We acknowledge generous start-up funds from the State University of New York at Stony Brook in support of this work. We also thank TOSOH F-Tech, Inc. for providing us TMSCF3 reagent for the synthesis of Togni reagent II.

1. Precursor Preparation: Synthesis of Methyl 4-(N-hydroxyacetamido)benzoate (1a)
<ol>
	<li>Reduction of methyl 4-nitrobenzoate.
	<ol>
		<li>Add 5.00 g of methyl 4-nitrobenzoate (27.6 mmol, 1.00 equiv), 159 mg of 5% Rhodium on carbon (Rh/C, 0.300 mol% Rh), and a magnetic stir-bar into an oven-dried 250 ml two-neck round-bottom flask (dried at 150 &#176;C for 18 hr). 
		NOTE: Reagents can be weighed out under ambient atmosphere. However, the reaction needs to be carried out under nitrogen atmosphere.</li>
		<li>Connect one neck of the flask to a nitrogen/vacuum manifold and cap the other neck with a septum. Perform three vacuum-refill cycles (i.e., pumping the air out of the flask and replacing the resulting vacuum with nitrogen gas) to replace the air in the flask with nitrogen gas.</li>
		<li>Add 138 ml anhydrous tetrahydrofuran (THF, 0.200 M) to the reaction flask using airtight syringe. Cool and stir the reaction mixture at 0 &#176;C for 15 min.</li>
		<li>Add 1.47 ml of hydrazine monohydrate (1.52 g, 30.4 mmol, 1.20 equiv) dropwise to the reaction mixture at 0 &#176;C using an airtight syringe. Monitor the reaction using a thin layer chromatography (TLC). Use hexanes:ethyl acetate (EtOAc) (4:1 v/v, Rf = 0.23) as an eluent to develop the TLC.</li>
		<li>When methyl 4-nitrobenzoate is completely consumed, filter the reaction mixture through a short pad of diatomaceous earth (i.e., Celite, 5 g) in a 60 ml frit Buchner funnel using vacuum filtration. Wash the filter with EtOAc (20 ml x 3 times). Concentrate the filtrate in vacuo using a rotary evaporator to afford the crude methyl 4-(N-hydroxyamino)benzoate, which is used directly without further purification.</li>
	</ol>
	</li>
	<li>Acetyl protection of methyl 4-(N-hydroxyamino)benzoate
	<ol>
		<li>Add 2.55 g of sodium bicarbonate (NaHCO3, 30.4 mmol, 1.20 equiv), all the crude methyl 4-(N-hydroxyamino)benzoate obtained from the previous step, and a stir-bar into an oven-dried 500 ml two-neck round-bottom flask.</li>
		<li>Cap one neck with a septum and connect another neck to a nitrogen/vacuum manifold. Perform three vacuum-refill cycles to replace the air in the flask with nitrogen gas.</li>
		<li>Add 138 ml anhydrous diethyl ether (Et2O, 0.200 M) to the reaction flask using an airtight syringe. Cool and stir the reaction mixture at 0 &#176;C for 15 min.</li>
		<li>Prepare a solution of acetyl chloride (2.17 ml, 2.39 g, 30.4 mmol, 1.20 equiv) in anhydrous Et2O (138 ml, 0.220 M). Add the solution to the reaction mixture at 0 &#176;C using a syringe pump at a rate of 10.0 ml/hr.</li>
		<li>At the end of the addition, filter the reaction mixture through a short pad of diatomaceous earth (i.e., Celite, 5 g) in 60 ml frit Buchner funnel using vacuum filtration. Wash the filter with EtOAc (20 ml x 3 times). Concentrate the filtrate in vacuo using a rotary evaporator.</li>
		<li>Purify the crude product with flash column chromatography35 eluting with hexanes:EtOAc (4:1 to 1:1 (v/v)) (Rf = 0.13, hexanes:EtOAc (4:1 (v/v)) to afford 5.31 g of methyl 4-(N-hydroxyacetamido)benzoate as a light yellow solid (25.4 mmol, 92% yield).</li>
	</ol>
	</li>
</ol>
2. Synthesis of Methyl 4-(N-(trifluoromethoxy)acetamido)benzoate (2a)
<ol>
	<li>Add 2.00 g of methyl 4-(N-hydroxyacetamido) benzoate (1a) (9.56 mmol, 1.00 equiv), 311 mg of Cs2CO3 (0.956 mmol, 10.0 mol%), 3.63 g of Togni reagent II (11.5 mmol, 1.20 equiv), and a magnetic stir-bar into an oven-dried 250 ml round-bottom flask inside a glovebox (nitrogen atmosphere). 
	NOTE: This reaction can also be performed using Schlenk techniques outside the glovebox. 
	Caution: Pure Togni reagent II is impact and friction sensitive, open flames, sparks, and/or grinding should be avoided. Soft and polished tools should be used for manipulations. In addition, the reaction mixture should be stirred behind a safety shield.36</li>
	<li>Add 95.6 ml of dried and degassed chloroform (CHCl3, 0.100 M) to the reaction flask.</li>
	<li>Cap the flask with septum and stir the reaction mixture at 23 &#176;C under N2 atmosphere either inside or outside of the glovebox for 16 hr.</li>
	<li>Filter the reaction mixture through a filter funnel to remove any solid residue. Concentrate the filtrate in vacuo using a rotary evaporator.</li>
	<li>Purify the crude product with flash column chromatography eluting with hexanes:dichloromethane (CH2Cl2) (7:3 to 0:1 (v/v)) (Rf = 0.44 (CH2Cl2) to afford 2.51 g of methyl 4-(N-(trifluoromethoxy)acetamido)benzoate (9.05 mmol, 95% yield). 
	NOTE: Togni reagent II is prepared according to the literature procedures37 and stored in the glovebox freezer at -35 &#176;C to maintain its quality over a long period of time. This reaction is oxygen sensitive. Although all the reagents can be weighed out under ambient atmosphere at RT, removal of all oxygen from the reaction flask is critical. Dried and degassed CHCl3 is prepared by distilling it from CaH2 under nitrogen atmosphere followed by performing a three cycles of the freeze-pump-thaw procedure.</li>
</ol>
3. Synthesis of Methyl 4-Acetamido-3-(trifluoromethoxy)benzoate via OCF3-migration (3a)
<ol>
	<li>Add 2.51 g methyl 4-(N-(trifluoromethoxy)acetamido)benzoate (9.05 mmol, 1.0 equiv), a magnetic stir-bar, and 9.05 ml of MeNO2 (1.00 M) into a 50 ml pressure vessel. Cap the vessel with a screw cap.</li>
	<li>Stir the reaction mixture at 120 &#176;C behind the safety shield for 20 hr. 
	Caution: Impure nitromethane is explosive, so the reaction mixture should be stirred behind the safety shield.</li>
	<li>Cool the reaction mixture to RT.</li>
	<li>Transfer the reaction mixture to a 100 ml round-bottom flask.</li>
	<li>Concentrate the reaction mixture in vacuo using a rotary evaporator.</li>
	<li>Purify the crude product with flash column chromatography eluting with hexanes:EtOAc (9:1 to 7:3 (v/v)) (Rf = 0.51 hexanes:EtOAc (4:1 (v/v)) to afford 2.13 g of methyl 4-acetamido-3-(trifluoromethoxy)benzoate (7.69 mmol, 85%). 
	NOTE: This reaction can be carried out under ambient atmosphere. Nitrogen atmosphere is not required. A round-bottom flask equipped with a water condenser can be used as an alternative reaction apparatus.</li>
</ol>
4. Characterization of New Products
<ol>
	<li>Characterize all the new compounds by 1H, 13C NMR spectroscopy and high-resolution mass spectroscopy and use 19F NMR spectroscopy to characterize compounds containing fluorine atoms.34</li>
</ol>

<ol>
	<li>Yagupolskii, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sintez+proizvodnykh+feniltriftormetilovogo+efira.">Sintez proizvodnykh feniltriftormetilovogo efira.</a> Dokl. Akad. Nauk SSSR. 105, 100-102 (1955).</li><li>Booth, H. S., Burchfield, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorination+of+halogeno+methyl+ethers.+I.+Fluorination+of+trichlorodimethyl+ether.">Fluorination of halogeno methyl ethers. I. Fluorination of trichlorodimethyl ether.</a> J. Am. Chem. Soc. 57, 2070 (1935).</li><li>McClinton, M. A., McClinton, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trifluoromethylations+and+related+reactions+in+organic-chemistry.">Trifluoromethylations and related reactions in organic-chemistry.</a> Tetrahedron. 48, 6555-6666 (1992).</li><li>Hansch, C., Leo, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Substituent Constants for Correlation Analysis in Chemistry and Biology. , (1979).</li><li>Leroux, F., Jeschke, P., Schlosser, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alpha-fluorinated+ethers,+thioethers,+and+amines:+Anomerically+biased+species.">Alpha-fluorinated ethers, thioethers, and amines: Anomerically biased species.</a> Chem. Rev. 105, 827-856 (2005).</li><li>Jeschke, P., Baston, E., Leroux, F. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alpha-fluorinated+ethers+as+'exotic'+entity+in+medicinal+chemistry.">Alpha-fluorinated ethers as 'exotic' entity in medicinal chemistry.</a> Mini-Rev. Med. Chem. 7, 1027-1034 (2007).</li><li>Leroux, F. R., Manteau, B., Vors, J. P., Pazenok, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trifluoromethyl+ethers+-+synthesis+and+properties+of+an+unusual+substituent.">Trifluoromethyl ethers - synthesis and properties of an unusual substituent.</a> Beilstein J. Org. Chem. 4, (2008).</li><li>Fantasia, S., Welch, J. M., Togni, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reactivity+of+a+hypervalent+iodine+trifluoromethylating+reagent+toward+THF:+ring+opening+and+formation+of+trifluoromethyl+ethers.">Reactivity of a hypervalent iodine trifluoromethylating reagent toward THF: ring opening and formation of trifluoromethyl ethers.</a> J. Org. Chem. 75, 1779-1782 (2010).</li><li>Manteau, B., Pazenok, S., Vors, J. P., Leroux, F. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+trends+in+the+chemistry+of+alpha-fluorinated+ethers,+thioethers,+amines+and+phosphines.">New trends in the chemistry of alpha-fluorinated ethers, thioethers, amines and phosphines.</a> J. Fluorine Chem. 131, 140-158 (2010).</li><li>Landelle, G., Panossian, A., Leroux, F. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trifluoromethyl+ethers+and+-thioethers+as+tools+for+medicinal+chemistry+and+drug+discovery.">Trifluoromethyl ethers and -thioethers as tools for medicinal chemistry and drug discovery.</a> Curr. Top. Med. Chem. 14, 941-951 (2014).</li><li>Liang, T., Neumann, C. N., Ritter, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Introduction+of+fluorine+and+fluorine-containing+functional+groups.">Introduction of fluorine and fluorine-containing functional groups.</a> Angew. Chem. Int. Ed. 52, 8214-8264 (2013).</li><li>Yarovenko, N. N., Vasileva, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+method+for+the+introduction+of+trihalomethyl+groups+into+organic+molecules.">A new method for the introduction of trihalomethyl groups into organic molecules.</a> Zh. Obshch. Khim. 28, 2502-2504 (1958).</li><li>Yagupols, L., Troitskaya, V. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+phenyl+trifluoromethyl+ether+derivatives.">Synthesis of phenyl trifluoromethyl ether derivatives.</a> Zh. Obshch. Khim. 31, 915-924 (1961).</li><li>Yagupolskii, L. M., Orda, V. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bis(triftormetoksi+I+triftormetilmerkapto)-proizvodnye+benzola.">Bis(triftormetoksi I triftormetilmerkapto)-proizvodnye benzola.</a> Zh. Obshch. Khim. 34, 1979-1984 (1964).</li><li>Louw, R., Franken, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+side-chain+chlorination+of+methoxybenzenes.">Selective side-chain chlorination of methoxybenzenes.</a> Chem Ind-London. , 127-128 (1977).</li><li>Feiring, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemistry+in+hydrogen-fluoride.+7.+Novel+synthesis+of+aryl+trifluoromethyl+ethers.">Chemistry in hydrogen-fluoride. 7. Novel synthesis of aryl trifluoromethyl ethers.</a> J. Org. Chem. 44, 2907-2910 (1979).</li><li>Salome, J., Mauger, C., Brunet, S., Schanen, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+conditions+and+activity+of+various+Lewis+acids+for+the+fluorination+of+trichloromethoxy-benzene+by+HF+in+liquid+phase.">Synthesis conditions and activity of various Lewis acids for the fluorination of trichloromethoxy-benzene by HF in liquid phase.</a> J. Fluorine Chem. 125, 1947-1950 (2004).</li><li>Sheppard, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alpha-Fluorinated+Ethers.+I.+Aryl+Fluoroalkyl+Ethers.">Alpha-Fluorinated Ethers. I. Aryl Fluoroalkyl Ethers.</a> J. Org. Chem. 29, 1-11 (1964).</li><li>Kuroboshi, M., Suzuki, K., Hiyama, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidative+desulfurization-fluorination+of+xanthates+-+a+convenient+synthesis+of+trifluoromethyl+ethers+and+difluoro(methylthio)methyl+ethers.">Oxidative desulfurization-fluorination of xanthates - a convenient synthesis of trifluoromethyl ethers and difluoro(methylthio)methyl ethers.</a> Tetrahedron Lett. 33, 4173-4176 (1992).</li><li>Kanie, K., Tanaka, Y., Suzuki, K., Kuroboshi, M., Hiyama, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+convenient+synthesis+of+trifluoromethyl+ethers+by+oxidative+desulfurization-fluorination+of+dithio+carbonates.">A convenient synthesis of trifluoromethyl ethers by oxidative desulfurization-fluorination of dithio carbonates.</a> Bull. Chem. Soc. Jpn. 73, 471-484 (2000).</li><li>Kuroboshi, M., Kanie, K., Hiyama, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidative+desulfurization-fluorination:+A+facile+entry+to+a+wide+variety+of+organofluorine+compounds+leading+to+novel+liquid-crystalline+materials.">Oxidative desulfurization-fluorination: A facile entry to a wide variety of organofluorine compounds leading to novel liquid-crystalline materials.</a> Adv. Synth. Catal. 343, 235-250 (2001).</li><li>Umemoto, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophilic+perfluoroalkylating+agents.">Electrophilic perfluoroalkylating agents.</a> Chem. Rev. 96, 1757-1777 (1996).</li><li>Umemoto, T., Adachi, K., Ishihara, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CF3+oxonium+salts,+O-(trifluoromethyl)dibenzofuranium+salts:+in+situ+synthesis,+properties,+and+application+as+a+real+CF3++species+reagent.">CF3 oxonium salts, O-(trifluoromethyl)dibenzofuranium salts: in situ synthesis, properties, and application as a real CF3+ species reagent.</a> J. Org. Chem. 72, 6905-6917 (2007).</li><li>Stanek, K., Koller, R., Togni, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reactivity+of+a+10-I-3+hypervalent+iodine+trifluoromethylation+reagent+with+phenols.">Reactivity of a 10-I-3 hypervalent iodine trifluoromethylation reagent with phenols.</a> J. Org. Chem. 73, 7678-7685 (2008).</li><li>Koller, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zinc-mediated+formation+of+trifluoromethyl+ethers+from+alcohols+and+hypervalent+iodine+trifluoromethylation+reagents.">Zinc-mediated formation of trifluoromethyl ethers from alcohols and hypervalent iodine trifluoromethylation reagents.</a> Angew. Chem. Int. Ed. 48, 4332-4336 (2009).</li><li>Trainor, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+preparation+of+O-trifluoromethyl+carbohydrates.">The preparation of O-trifluoromethyl carbohydrates.</a> J. Carbohydr. Chem. 4, 545-563 (1985).</li><li>Nishida, M., Vij, A., Kirchmeier, R. L., Shreeve, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+polyfluoro+aromatic+ethers+-+a+facile+route+using+polyfluoroalkoxides+generated+from+carbonyl+and+trimethysilyl+compounds.">Synthesis of polyfluoro aromatic ethers - a facile route using polyfluoroalkoxides generated from carbonyl and trimethysilyl compounds.</a> Inorg. Chem. 34, 6085-6092 (1995).</li><li>Kolomeitsev, A. A., Vorobyev, M., Gillandt, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Versatile+application+of+trifluoromethyl+triflate.">Versatile application of trifluoromethyl triflate.</a> Tetrahedron Lett. 49, 449-454 (2008).</li><li>Marrec, O., Billard, T., Vors, J. P., Pazenok, S., Langlois, B. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+deeper+insight+into+direct+trifluoromethoxylation+with+trifluoromethyl+triflate.">A deeper insight into direct trifluoromethoxylation with trifluoromethyl triflate.</a> J. Fluorine Chem. 131, 200-207 (2010).</li><li>Marrec, O., Billard, T., Vors, J. P., Pazenok, S., Langlois, B. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+and+direct+trifluoromethoxylation+of+aliphatic+substrates+with+2,4-dinitro(trifluoromethoxy)benzene.">A new and direct trifluoromethoxylation of aliphatic substrates with 2,4-dinitro(trifluoromethoxy)benzene.</a> Adv. Synth. Catal. 352, 2831-2837 (2010).</li><li>Huang, C. H., Liang, T., Harada, S., Lee, E., Ritter, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silver-mediated+trifluoromethoxylation+of+aryl+stannanes+and+arylboronic+acids.">Silver-mediated trifluoromethoxylation of aryl stannanes and arylboronic acids.</a> J. Am. Chem. Soc. 133, 13308-13310 (2011).</li><li>Rozen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+fluorinations+by+reagents+containing+the+OF+group.">Selective fluorinations by reagents containing the OF group.</a> Chem. Rev. 96, 1717-1736 (1996).</li><li>Venturini, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+trifluoro-methoxylation+of+aromatics+with+perfluoro-methyl-hypofluorite.">Direct trifluoro-methoxylation of aromatics with perfluoro-methyl-hypofluorite.</a> J. Fluorine Chem. 140, 43-48 (2012).</li><li>Hojczyk, K. N., Feng, P., Zhan, C., Ngai, M. -. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trifluoromethoxylation+of+arenes:+synthesis+of+ortho-trifluoromethoxylated+aniline+derivatives+by+OCF3+migration.">Trifluoromethoxylation of arenes: synthesis of ortho-trifluoromethoxylated aniline derivatives by OCF3 migration.</a> Angew. Chem. Int. Ed. 53, 14559-14563 (2014).</li><li>Still, W. C., Kahn, M., Mitra, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+chromatographic+technique+for+preparative+separations+with+moderate+Resolution.">Rapid chromatographic technique for preparative separations with moderate Resolution.</a> J. Org. Chem. 43, 2923-2925 (1978).</li><li>Fiederling, N., Haller, J., Schramm, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Notification+about+the+Explosive+Properties+of+Togni's+Reagent+II+and+One+of+Its+Precursors.">Notification about the Explosive Properties of Togni's Reagent II and One of Its Precursors.</a> Org. Process Res. Dev. 17, 318-319 (2013).</li><li>Matousek, V., Pietrasiak, E., Schwenk, R., Togni, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-pot+synthesis+of+hypervalent+iodine+reagents+for+electrophilic+trifluoromethylation.">One-pot synthesis of hypervalent iodine reagents for electrophilic trifluoromethylation.</a> J. Org. Chem. 78, 6763-6768 (2013).</li></ol>

The authors declare no competing financial interests.

Due to the lack of a general and user-friendly procedure for the synthesis of trifluoromethoxylated arenes, many OCF3-containing aromatic compounds are extremely expensive.34 Our strategy displaces a broad functional group tolerance and provides an easy access to various trifluoromethoxylated arenes. These compounds could serve as valuable building blocks for the discovery and development of new pharmaceuticals, agrochemicals, and materials.
Hydrazine was used as a hydrogen source for the rhodium-catalyzed reduction of nitroarenes. Its quality is one of the keys in obtaining the reduction products in high yields. The reduction yields dropped when a few-month old hydrazine was used. To ensure the reproducibility, we transferred some of the hydrazine from a large commercial bottle to a smaller 20 ml vial and used it from the 20 ml vial. In addition, we stored it in the refrigerator (4 &#176;C) to slow down the rate of decomposition. Moreover, slow addition of hydrazine is crucial in getting clean hydroxylamines in good yields.
The O-trifluoromethylation is a radical mediated process, so exclusion of oxygen from the reaction mixture is critical. Using un-degassed chloroform as the solvent or performing the reaction under ambient atmosphere resulted in lower yield. Our preliminary mechanistic studies shown that the OCF3-migration process involved thermally induced heterolytic cleavage of the N-OCF3 bond to generate a tight ion pair of nitrenium ion and trifluoromethoxide.34 Trifluoromethoxide attacks the ortho-position of the nitrenium ion followed by the tautomerization to afford the desired ortho-trifluoromethoxylated aniline derivatives. Formation of the nitrenium ion in electron deficient substrates is energetically disfavored and thus requires higher reaction temperature.
In summary, we reported a general and laboratory scale synthetic protocol for the regioselective synthesis of ortho-OCF3 aniline derivatives. This strategy has several unique features: (i) a wide range of functional groups and substitution patterns are tolerated; (ii) the operational simplicity of our protocol would render trifluoromethoxylation available to broader synthetic community; and (iii) the final products are novel and could be used as useful synthetic building blocks for life and materials science research. Some troubleshooting procedures are outlined here: (i) store the reduction product, aryl hydroxyl amine, in the freezer or immediately use it for the next step; (ii) monitor the reduction/protection reactions closely with TLC to avoid over reduction of nitroarenes or protection of N-hydroxyamines; (iii) exclusion of oxygen from the reaction mixtures is critical for the reduction of nitroarenes and O-trifluoromethylation; (iv) higher reaction temperature is needed for electron deficient arenes in the intramolecular OCF3-migration step.

The trifluoromethoxy (OCF3) group has made a profound impact on life and materials science research since the first synthesis of trifluoromethyl ether in 1935.2 Due to its unique combination of high electronegativity (&#967; = 3.7)3 and excellent lipophilicity (&#928;x = 1.04),4 the trifluoromethoxy group has found broad applications in medicine, agriculture, and materials industry.5-10 However, facile introduction of the OCF3 group into organic molecules, especially aromatic compounds, remains a major challenge in synthetic chemistry.
Over the last few decades, efforts to address this challenge led to the development of a handful of transformations for the synthesis of trifluoromethoxylated arenes.5-7,9-11 These include (i) chlorine/fluorine exchange on trichlorinated precursors;1,12-17 (ii) deoxyfluorination of fluoroformates;18 (iii) oxidative fluorodesulfurization;19-21 (iv) electrophilic trifluoromethylation of alcohols;22-25 (v) nucleophilic trifluoromethoxylation;26-30, (vi) transition metal-mediated trifluoromethoxylation of aryl borates and stannanes;31 and (vii) radical trifluoromethoxylation.32,33 Nevertheless, many of these approaches either suffer from poor substrate scope or require use of highly toxic and/or thermally labile reagents. Therefore, due to the lack of a general and user-friendly method to synthesize OCF3-containing compounds, the potential of the OCF3 group has not been fully exploited in chemistry.
As part of our interest in trifluoromethoxylation reactions,34 we describe herein a two-step protocol (i.e., radical&#160;O-trifluoromethylation and thermally induced OCF3-migration) for the synthesis of methyl 4-acetamido-3-(trifluoromethoxy)benzoate (3a) from methyl 4-(N-hydroxyacetamido)benzoate (1a). The strategy is easy-to-operate and applicable to the synthesis of a wide range of ortho-trifluoromethoxylated aniline derivatives.

<table border="0" cellpadding="0" cellspacing="0" width="573">
	<tbody>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">5% Rhodium on carbon</td>
			<td style="width:71px;">Aspira Scientific</td>
			<td style="width:119px;">300835</td>
			<td style="width:167px;">5% wt% dry loading</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">hydrazine monohydrate</td>
			<td style="width:71px;">Sigma-Alderich</td>
			<td style="width:119px;">13696HMV</td>
			<td style="width:167px;">Reagent grade, 98%</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">Acetyl chloride</td>
			<td style="width:71px;">Alfa Aesar</td>
			<td style="width:119px;">10176887</td>
			<td style="width:167px;">98%</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">Sodium bicarbonate</td>
			<td style="width:71px;">Fisher Scientific</td>
			<td style="width:119px;">134826</td>
			<td style="width:167px;">Chemical pure</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">Cesium carbonate</td>
			<td style="width:71px;">Alfa Aesar</td>
			<td style="width:119px;">12887</td>
			<td style="width:167px;">99.9%, metals basis</td>
		</tr>
		<tr height="148">
			<td height="148" style="height:148px;width:216px;">Togni Reagent II</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td style="width:167px;">Prepared according to the literature procedure (ref 37). Caution: Pure Togni reagent II is impact and friction sensitive, treat it with great care (see ref. 36).</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:216px;">Tetrahydrofuran</td>
			<td style="width:71px;">BDH</td>
			<td style="width:119px;">BDH1149-4LG</td>
			<td style="width:167px;">Distilled from deep purple sodium benzophenone ketyl.</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:216px;">Diethyl Ether</td>
			<td style="width:71px;">Fisher Scientific</td>
			<td style="width:119px;">148221</td>
			<td style="width:167px;">Distilled from deep purple sodium benzophenone ketyl.</td>
		</tr>
		<tr height="47">
			<td height="47" style="height:47px;width:216px;">Chloroform</td>
			<td style="width:71px;">Fisher Scientific</td>
			<td style="width:119px;">141739</td>
			<td style="width:167px;">Dried over CaH2 and distilled</td>
		</tr>
		<tr height="47">
			<td height="47" style="height:47px;width:216px;">nitro methane</td>
			<td style="width:71px;">Alfa Aesar</td>
			<td style="width:119px;">J03z053</td>
			<td style="width:167px;">Dried over CaSO4 and distilled</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">Silica gel</td>
			<td style="width:71px;">SILICYCLE</td>
			<td style="width:119px;">60514</td>
			<td style="width:167px;">40-63 &#181;m (230-400 mesh)</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:216px;">Cilite</td>
			<td style="width:71px;">EMD</td>
			<td style="width:119px;">2012040674</td>
			<td style="width:167px;">Not acid washed</td>
		</tr>
	</tbody>
</table>

protocol for the synthesis of ortho-trifluoromethoxylated aniline derivatives

Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of trifluoromethoxylated aromatic compounds remains a formidable challenge in organic synthesis. Conventional approaches often suffer from poor substrate scope, or require use of highly toxic, difficult-to-handle, and/or thermally labile reagents. Herein, we report a user-friendly protocol for the synthesis of methyl 4-acetamido-3-(trifluoromethoxy)benzoate using 1-trifluoromethyl-1,2-benziodoxol-3(1H)-one (Togni reagent II). Treating methyl 4-(N-hydroxyacetamido)benzoate (1a) with Togni reagent II in the presence of a catalytic amount of cesium carbonate (Cs2CO3) in chloroform at RT afforded methyl 4-(N-(trifluoromethoxy)acetamido)benzoate (2a). This intermediate was then converted to the final product methyl 4-acetamido-3-(trifluoromethoxy)benzoate (3a) in nitromethane at 120 &#176;C. This procedure is general and can be applied to the synthesis of a broad spectrum of ortho-trifluoromethoxylated aniline derivatives, which could serve as useful synthetic building blocks for the discovery and development of new pharmaceuticals, agrochemicals, and functional materials.

Methyl 4-(N-hydroxyacetamido)benzoate (1a) was synthesized in 92% isolated yield through a two-step procedure (i.e., reducing methyl 4-nitrobenzoate with hydrazine using 5% Rh/C as a catalyst to form methyl 4-(N-hydroxyamino)benzoate, followed by acetyl protection of the resulting hydroxylamine). O-Trifluoromethylation of 1a with Togni reagent II in the presence of catalytic amount of cesium carbonate (Cs2CO3) in chloroform at RT afforded the desired 4-(N-(trifluoromethoxy)acetamido)benzoate (2a) in 95% isolated yield. This compound underwent thermally induced OCF3-migration in MeNO2 at 120 &#176;C to give the desired methyl 4-acetamido-3-(trifluoromethoxy)benzoate (3a) in 85% isolated yield.
The 1H, 13C, and 19F NMR spectrum of the final product 3a are depicted in Figure 1, Figure 2, and Figure 3, respectively. A distinguish quartet peak at 120.6 ppm with a large coupling constant (258.9 Hz) in 13C NMR spectra corresponds to the CF3 carbon. When the OCF3-migration takes place, a sharp change in the 19F NMR from -65 ppm (2a) to -58.1ppm (3a) is observed. The detail characterization data of 3a is reported as follow: Rf = 0.51 (hexanes/EtOAc 4:1 (v/v)). NMR Spectroscopy: 1H NMR (700 MHz, CDCl3, 25 &#176;C, &#948;): 8.56 (d, J = 8.6 Hz, 1H), 7.97 (d, J = 8.6 Hz, 1H), 7.93 (s, 1H), 7.56 (br. s, 1H), 3.92 (s, 3H), 2.27 (s, 3H). 13C NMR (175 MHz, CDCl3, 25 &#176;C, &#948;): 168.5, 165.6, 137.2, 134.7, 129.3, 125.8, 121.5, 120.8, 120.6 (q, J = 258.9 Hz), 52.5, 25.2. 19F NMR (376 MHz, CDCl3, 25 &#176;C, &#948;): -58.1 (s). Mass Spectrometry: HRMS (ESI-TOF) (m/z): calcd for C11H11NO4F3 ([M + H]+) 278.0640, found 278.0643.
This protocol is general and applicable to a wide array of aromatic compounds (Table 1). The reaction tolerates a broad spectrum of functional groups including ester (3a, 3d), ketone (3b), nitrile (3c), ethers (3e, 3m), halogens (3g - 3l), CF3 group (3m, 3n), amide (3o) and heterocycle substituent (3o). The halogen substituents, especially Br and I, are particularly useful because they provide synthetic handles for further functionalization. In addition, high levels of ortho- over para-selectivity are observed (3f, 3k - 3l). In the presence of two non-identical ortho positions, low levels of regiocontrol are obtained (3d, 3e, 3k, 3m). Furthermore, the reaction temperature for the OCF3-migration step depends on the electronic nature of arenes. Generally, more electron deficient arenes require higher reaction temperature.
<img alt="Figure 1" src="/files/ftp_upload/53789/53789fig1.jpg" />
Figure 1. 1H NMR spectrum of 3a. Chemical shift and relative integration of characteristic protons are labeled. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53789/53789fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" src="/files/ftp_upload/53789/53789fig2.jpg" />
Figure 2. 13C NMR spectrum of 3a. Chemical shift of characteristic carbons is labeled. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53789/53789fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" src="/files/ftp_upload/53789/53789fig3.jpg" />
Figure 3. 19F NMR spectrum of 3a. Chemical shift of characteristic fluorine is labeled using trifluorotoluene (-63.3 ppm) as internal reference. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53789/53789fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Table 1" src="/files/ftp_upload/53789/53789table1highres.jpg" width="700" />
Table 1. Selected examples of trifluoromethoxylation of arenes. Reaction time: 11-48 hr. Cited yields and isomeric ratios are for OCF3-migration step (from 2 to 3) and of isolated material by flash column chromatography. [a] 50 &#176;C. [b] 120 &#176;C. [c] 140 &#176;C. [d] Less than 5% para-product was detected. THF = Tetrahydrofuran; AcCl = acetyl chloride. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53789/53789table1highres.jpg" target="_blank">Please click here to view a larger version of this table.</a>

Watch this Scientific Journal Video about Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives at JoVE.com

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

An operationally simple procedure for the synthesis of ortho-trifluoromethoxylated aniline derivatives via a two-step sequence of O-trifluoromethylation of N-aryl-N-hydroxyacetamide followed by thermally induced intramolecular OCF3-migration is reported.

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of ...

protocol-for-synthesis-ortho-trifluoromethoxylated-aniline

Nanyang Technological University

Research

Education

JoVE Core

JoVE Journal

Organic Chemistry

Chemistry

Unit 1

Aromatic Compounds

SCIENTISTS IN ACTION

9.8K Views.  State University of New York at Stony Brook. An operationally simple procedure for the synthesis of ortho-trifluoromethoxylated aniline derivatives via a two-step sequence of O-trifluoromethylation of N-aryl-N-hydroxyacetamide followed by thermally induced intramolecular OCF3-migration is reported.

Video: Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes

The procedures described in this article involve the synthesis and isolation of hypervalent iodonium alkynyl triflates (HIATs) and their subsequent reactions with azides to form cyanocarbene intermediates. The synthesis of hypervalent iodonium alkynyl triflates can be facile, but difficulties stem from their isolation and reactivity. In particular, the necessity to use filtration under inert atmosphere at -45 &deg;C for some HIATs requires special care and equipment. Once isolated, the compounds can be stored and used in reactions with azides to form cyanocarbene intermediates. 
The evidence for cyanocarbene generation is shown by visible extrusion of dinitrogen as well as the characterization of products that occur from O-H insertion, sulfoxide complexation, and cyclopropanation. A side reaction of the cyanocarbene formation is the generation of a vinylidene-carbene and the conditions to control this process are discussed. There is also potential to form a hypervalent iodonium alkenyl triflate and the means of isolation and control of its generation are provided. The O-H insertion reaction involves using a HIAT, sodium azide or tetrabutylammonium azide, and methanol as solvent/substrate. The sulfoxide complexation reaction uses a HIAT, sodium azide or tetrabutylammonium azide, and dimethyl sulfoxide as solvent. The cyclopropanations can be performed with or without the use of solvent. The azide source must be tetrabutylammonium azide and the substrate shown is styrene.

Herein is described the synthesis, isolation, and reactions of hypervalent iodonium alkynyl triflates (HIATs) with azides to generate cyanocarbenes. The procedures will involve air-sensitive and cryogen techniques, including cold filtration under an inert atmosphere. Handling and safety of the synthesized compounds will also be discussed.

The procedures described in this article involve the synthesis and isolation of hypervalent iodonium alkynyl triflates (HIATs) and their subsequent ...

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides (CHIPS)

The direct functionalization of C-H bonds is an important and long standing goal in organic chemistry. Such transformations can be very powerful in order to streamline synthesis by saving steps, time and material compared to conventional methods that require the introduction and removal of activating or directing groups. Therefore, the functionalization of C-H bonds is also attractive for green chemistry. Under oxidative conditions, two C-H bonds or one C-H and one heteroatom-H bond can be transformed to C-C and C-heteroatom bonds, respectively. Often these oxidative coupling reactions require synthetic oxidants, expensive catalysts or high temperatures. Here, we describe a two-step procedure to functionalize indole derivatives, more specifically tetrahydrocarbazoles, by C-H amination using only elemental oxygen as oxidant. The reaction uses the principle of C-H functionalization via Intermediate PeroxideS (CHIPS). In the first step, a hydroperoxide is generated oxidatively using visible light, a photosensitizer and elemental oxygen. In the second step, the N-nucleophile, an aniline, is introduced by Br&#248;nsted-acid catalyzed activation of the hydroperoxide leaving group. The products of the first and second step often precipitate and can be conveniently filtered off. The synthesis of a biologically active compound is shown.

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides CHIPS

A two-step procedure for the synthesis of pharmaceutically active indole-derivatives by C-H functionalization with anilines is described, using photo- and Br&#248;nsted acid catalysis.

The direct functionalization of C-H bonds is an important and long standing goal in organic chemistry. Such transformations can be very powerful in order ...

A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products

The guanidine functional group, displayed most prominently in the amino acid arginine, one of the fundamental building blocks of life, is an important structural element found in many complex natural products and pharmaceuticals. Owing to the continual discovery of new guanidine-containing natural products and designed small molecules, rapid and efficient guanidinylation methods are of keen interest to synthetic and medicinal organic chemists. Because the nucleophilicity and basicity of guanidines can affect subsequent chemical transformations, traditional, indirect guanidinylation is typically pursued. Indirect methods commonly employ multiple protection steps involving a latent amine precursor, such as an azide, phthalimide, or carbamate. By circumventing these circuitous methods and employing a direct guanidinylation reaction early in the synthetic sequence, it was possible to forge the linear terminal guanidine containing backbone of clavatadine A to realize a short and streamlined synthesis of this potent factor XIa inhibitor. In practice, guanidine hydrochloride is elaborated with a carefully constructed protecting array that is optimized to survive the synthetic steps to come. In the preparation of clavatadine A, direct guanidinylation of a commercially available diamine eliminated two unnecessary steps from its synthesis. Coupled with the wide variety of known guanidine protecting groups, direct guanidinylation evinces a succinct and efficient practicality inherent to methods that find a home in a synthetic chemist&#39;s toolbox.

Here, we present a protocol for direct, early stage guanidinylation that enables rapid total synthesis of aminoguanidine-containing small organic molecules. An advanced synthetic intermediate used in the synthesis of a blood coagulation factor XIa inhibitor was prepared using this protocol.

The guanidine functional group, displayed most prominently in the amino acid arginine, one of the fundamental building blocks of life, is an important ...

HKUST-1 as a Heterogeneous Catalyst for the Synthesis of Vanillin

Vanillin (4-hydoxy-3-methoxybenzaldehyde) is the main component of the extract of vanilla bean. The natural vanilla scent is a mixture of approximately 200 different odorant compounds in addition to vanillin. The natural extraction of vanillin (from the orchid Vanilla planifolia, Vanilla tahitiensis and Vanilla pompon) represents only 1% of the worldwide production and since this process is expensive and very long, the rest of the production of vanillin is synthesized. Many biotechnological approaches can be used for the synthesis of vanillin from lignin, phenolic stilbenes, isoeugenol, eugenol, guaicol, etc., with the disadvantage of harming the environment since these processes use strong oxidizing agents and toxic solvents. Thus, eco-friendly alternatives on the production of vanillin are very desirable and thus, under current investigation. Porous coordination polymers (PCPs) are a new class of highly crystalline materials that recently have been used for catalysis. HKUST-1 (Cu3(BTC)2(H2O)3, BTC = 1,3,5-benzene-tricarboxylate) is a very well known PCP which has been extensively studied as a heterogeneous catalyst. Here, we report a synthetic strategy for the production of vanillin by the oxidation of trans-ferulic acid using HKUST-1 as a catalyst.

The conversion of trans-ferulic acid to vanillin was achieved by heterogeneous catalysis. HKUST-1 was employed in this synthesis and the essential step in the catalytic process was the generation of unsaturated metal sites. Thus, when the catalyst was activated under vacuum, full vanillin conversion (yield of 95%) was obtained.

Vanillin (4-hydoxy-3-methoxybenzaldehyde) is the main component of the extract of vanilla bean. The natural vanilla scent is a mixture of approximately ...

A Protocol for the Production of Gliadin-cyanoacrylate Nanoparticles for Hydrophilic Coating

This article presents a protocol for the production of protein-based nanoparticles that changes the hydrophobic surface to hydrophilic by a simple spray coating. These nanoparticles are produced by the polymerization reaction of alkyl cyanoacrylate on the surface of cereal protein (gliadin) molecules. Alkyl cyanoacrylate is a monomer that instantly polymerizes at RT when it is applied to the surface of materials. Its polymerization reaction is initiated by the trace amounts of weakly basic or nucleophilic species on the surface, including moisture. Once polymerized, the polymerized alkyl cyanoacrylates show a strong affinity with the object materials because nitrile groups are in the backbone of poly (alkyl cyanoacrylate). Proteins also work as initiator for this polymerization because they contain amine groups that can initiate the polymerization of cyanoacrylate. If aggregated protein is used as an initiator, protein aggregate is surrounded by the hydrophobic poly(alkyl cyanoacrylate) chains after the polymerization reaction of alkyl cyanoacrylate. By controlling the experimental condition, particles in the nanometer range are produced. The produced nanoparticles readily adsorb to the surface of most materials including glass, metals, plastics, wood, leather, and fabrics. When the surface of a material is sprayed with the produced nanoparticle suspension and rinsed with water, the micellar structure of nanoparticle changes its conformation, and the hydrophilic proteins are exposed to the air. As a result, the nanoparticle-coated surface changes to hydrophilic.

This article presents a protocol for the production of protein-based nanoparticles that changes the hydrophobic surface to hydrophilic. The produced nanoparticle is an assembly of gliadin-cyanoacrylate diblock copolymers. Spray coating with the produced nanoparticle changes the surface of target material to a hydrophilic surface.

This article presents a protocol for the production of protein-based nanoparticles that changes the hydrophobic surface to hydrophilic by a simple spray ...

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the development of antibody drug conjugates (ADCs) and nanomedicine, fluorescent microscopy and systems chemistry. For many of these applications, specificity of the bioconjugation method used is of prime concern. The Michael addition of maleimides with cysteine(s) on the target proteins is highly selective and proceeds rapidly under mild conditions, making it one of the most popular methods for protein bioconjugation.
We demonstrate here the modification of the only surface-accessible cysteine residue on yeast cytochrome c with a ruthenium(II) bisterpyridine maleimide. The protein bioconjugation is verified by gel electrophoresis and purified by aqueous-based fast protein liquid chromatography in 27% yield of isolated protein material. Structural characterization with MALDI-TOF MS and UV-Vis is then used to verify that the bioconjugation is successful. The protocol shown here is easily applicable to other cysteine - maleimide coupling of proteins to other proteins, dyes, drugs or polymers.

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

This protocol details the important steps required for the bioconjugation of a cysteine containing protein to a maleimide, including reagent purification, reaction conditions, bioconjugate purification and bioconjugate characterization.

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the ...

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins with the synthesis of a hydrophilic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) homopolymer using reversible addition-fragmentation chain-transfer (RAFT) polymerization. Under mild visible light irradiation (&#955; = 460 nm, 0.7 mW/cm2), this macro-chain transfer agent (macro-CTA) in the presence of a ruthenium based photoredox catalyst, Ru(bpy)3Cl2 can be chain extended with a second monomer to form a well-defined block copolymer in a process known as Photoinduced Electron Transfer RAFT (PET-RAFT). When PET-RAFT is used to chain extend POEGMA with benzyl methacrylate (BzMA) in ethanol (EtOH), polymeric nanoparticles with different morphologies are formed in situ according to a polymerization-induced self-assembly (PISA) mechanism. Self-assembly into nanoparticles presenting POEGMA chains at the corona and poly(benzyl methacrylate) (PBzMA) chains in the core occurs in situ due to the growing insolubility of the PBzMA block in ethanol. Interestingly, the formation of highly pure worm-like micelles can be readily monitored by observing the onset of a highly viscous gel in situ due to nanoparticle entanglements occurring during the polymerization. This process thereby allows for a more reproducible synthesis of worm-like micelles simply by monitoring the solution viscosity during the course of the polymerization. In addition, the light stimulus can be intermittently applied in an ON/OFF manner demonstrating temporal control over the nanoparticle morphology.

This article describes a process for producing polymeric self-assembled nanoparticles using visible light mediated dispersion polymerization. Using low energy visible light to control the polymerization allows for the reproducible formation of self-assembled worm-like micelles at high solids content.

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins ...

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2'-O-thiophenylmethyl Modification and Characterization via Circular Dichroism

Solid-phase synthesis has been used to obtain canonical and modified polymers of nucleic acids, specifically of DNA or RNA, which has made it a popular methodology for applications in various fields and for different research purposes. The procedure described herein focuses on the synthesis, purification, and characterization of dodecamers of RNA 5&#39;-[CUA CGG AAU CAU]-3&#39; containing zero, one, or two modifications located at the C2&#39;-O-position. The probes are based on 2-thiophenylmethyl groups, incorporated into RNA nucleotides via standard organic synthesis and introduced into the corresponding oligonucleotides via their respective phosphoramidites. This report makes use of phosphoramidite chemistry via the four canonical nucleobases (Uridine (U), Cytosine (C), Guanosine (G), Adenosine (A)), as well as 2-thiophenylmethyl functionalized nucleotides modified at the 2&#39;-O-position; however, the methodology is amenable for a large variety of modifications that have been developed over the years. The oligonucleotides were synthesized on a controlled-pore glass (CPG) support followed by cleavage from the resin and deprotection under standard conditions, i.e., a mixture of ammonia and methylamine (AMA) followed by hydrogen fluoride/triethylamine/N-methylpyrrolidinone. The corresponding oligonucleotides were purified via polyacrylamide electrophoresis (20% denaturing) followed by elution, desalting, and isolation via reversed-phase chromatography (Sep-pak, C18-column). Quantification and structural parameters were assessed via ultraviolet-visible (UV-vis) and circular dichroism (CD) photometric analysis, respectively. This report aims to serve as a resource and guide for beginner and expert researchers interested in embarking in this field. It is expected to serve as a work-in-progress as new technologies and methodologies are developed. The description of the methodologies and techniques within this document correspond to a DNA/RNA synthesizer (refurbished and purchased in 2013) that uses phosphoramidite chemistry.

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2'-O-thiophenylmethyl Modification and Characterization via Circular Dichroism

This article provides a detailed procedure on the solid-phase synthesis, purification, and characterization of dodecamers of RNA modified at the C2&#39;-O-position. UV-vis and circular dichroism photometric analyses are used to quantify and characterize structural aspects, i.e., single-strands or double-strands.

Solid-phase synthesis has been used to obtain canonical and modified polymers of nucleic acids, specifically of DNA or RNA, which has made it a popular ...

Synthesis and Mass Spectrometry Analysis of Oligo-peptoids

Peptoids are sequence-controlled peptide-mimicking oligomers consisting of N-alkylated glycine units. Among many potential applications, peptoids have been thought of as a type of molecular information storage. Mass spectrometry analysis has been considered the method of choice for sequencing peptoids. Peptoids can be synthesized via solid phase chemistry using a repeating two-step reaction cycle. Here we present a method to manually synthesize oligo-peptoids and to analyze the sequence of the peptoids using tandem mass spectrometry (MS/MS) techniques. The sample peptoid is a nonamer consisting of alternating N-(2-methyloxyethyl)glycine (Nme) and N-(2-phenylethyl)glycine (Npe), as well as an N-(2-aminoethyl)glycine (Nae) at the N-terminus. The sequence formula of the peptoid is Ac-Nae-(Npe-Nme)4-NH2, where Ac is the acetyl group. The synthesis takes place in a commercially available solid-phase reaction vessel. The rink amide resin is used as the solid support to yield the peptoid with an amide group at the C-terminus. The resulting peptoid product is subjected to sequence analysis using a triple-quadrupole mass spectrometer coupled to an electrospray ionization source. The MS/MS measurement produces a spectrum of fragment ions resulting from the dissociation of charged peptoid. The fragment ions are sorted out based on the values of their mass-to-charge ratio (m/z). The m/z values of the fragment ions are compared against the nominal masses of theoretically predicted fragment ions, according to the scheme of peptoid fragmentation. The analysis generates a fragmentation pattern of the charged peptoid. The fragmentation pattern is correlated to the monomer sequence of the neutral peptoid. In this regard, MS analysis reads out the sequence information of the peptoids.

A protocol is described for the manual synthesis of oligo-peptoids followed by sequence analysis by mass spectrometry.

Peptoids are sequence-controlled peptide-mimicking oligomers consisting of N-alkylated glycine units. Among many potential applications, peptoids have ...

The MPLEx Protocol for Multi-omic Analyses of Soil Samples

Mass spectrometry (MS)-based integrated metaproteomic, metabolomic, and lipidomic (multi-omic) studies are transforming our ability to understand and characterize microbial communities in environmental and biological systems. These measurements are even enabling enhanced analyses of complex soil microbial communities, which are the most complex microbial systems known to date. Multi-omic analyses, however, do have sample preparation challenges, since separate extractions are typically needed for each omic study, thereby greatly amplifying the preparation time and amount of sample required. To address this limitation, a 3-in-1 method for the simultaneous extraction of metabolites, proteins, and lipids (MPLEx) from the same soil sample was created by adapting a solvent-based approach. This MPLEx protocol has proven to be both simple and robust for many sample types, even when utilized for limited quantities of complex soil samples. The MPLEx method also greatly enabled the rapid multi-omic measurements needed to gain a better understanding of the members of each microbial community, while evaluating the changes taking place upon biological and environmental perturbations.

A protocol is presented for simultaneously extracting metabolites, proteins, and lipids from a single soil sample, allowing reduced sample preparation times and enabling multi-omic mass spectrometry analyses of samples with limited quantities.

Mass spectrometry (MS)-based integrated metaproteomic, metabolomic, and lipidomic (multi-omic) studies are transforming our ability to understand and ...