著者は、ヴァンダービルト大学や金融支援のための化学生物学研究所を認めるみたいと思います。高分解能質量スペクトル分析のためバークレー エリス氏と教授ジョン ・ マクレーンを認めた

1. 代表的な電子レンジ-脱硝を支援
<ol><li>アジドフェニル硝酸エステルを配置 (1.0 当量、0.2 モル) 8 mL マイクロ波反応瓶で。反応のスケールは、反応の進行に悪影響を及ぼすことがなくいくつかのモルに増加できます。</li>
	<li>20% アセトン (0.1 M、2.0 mL) アジドフェニル硝酸エステルを溶解します。反応容器にピリジン (5.0 当量、0.08 mL、1.0 モル) を追加します。マイクロ波照射バイアルのキャップ、マイクロ波リアクター共振器で反応容器を配置します。</li>
	<li>攪拌と固定保持時間 15 分の 120 ° C でソリューションを照射します。保持時間は、照射が指定温度および結果の圧力で発生するどのくらいの期間を表します。2 分ランプ間報告された温度のすべての反応を加熱します。組み込み赤外線センサーによって温度を監視します。</li>
	<li>15 分後出発原料の消費量を確認するため薄層クロマトグラフィー (TLC) を用いた反応混合物を分析します。1:1 酢酸エチル/ヘキサンを溶離液として使用します。<ol>
<li>セリウム アンモニウム molybate 染色を用いた TLC 板を視覚化します。反応体およびプロダクトの Rfは異なりますが、削減のアルコールは一般に 0.05 を 0.1 低い Rf反応液より。</li>
	</ol>
</li>
</ol>2、trichloroacetimidate の形成
<ol><li>出発原料の完全な消費は、次の航空会社の使用量を削減する溶剤を蒸発します。(ジクロロ メタン) CH2Cl2 (1.0 mL) で希釈し、水層を除去する注射器を使用します。水層を削除すると、氷水浴を使用して 0 の ° C に反応混合物を冷却します。</li>
	<li>次に、反応容器に DBU (10 eq、0.3 mL、1.9 ミリ モル) と 2,2,2 trichloroacetonitrile (50 eq、1.0 mL、10 m モル) を追加します。ベースの 1 相当と 2,2,2 trichloroacetonitrile の 1 と同等の最小値を必要し、両方の試薬が過剰に追加されます。</li>
	<li>周囲温度に温暖化しながら攪拌反応混合物を許可します。出発原料の消費量を確認する TLC による反応を監視します。<ol>
<li>1:1 酢酸エチル/ヘキサンを溶離液として使用します。セリウム アンモニウム molybate 染色を用いた TLC 板を視覚化します。反応体およびプロダクトの Rfは、異なります。</li>
	</ol>
</li>
	<li>開始材料の完全な消費の後回復フラスコに反応混合物を転送し、30 ° C で真空中で混合物を集中溶剤の蒸発は茶色の油に原油淡黄色を提供します。</li>
	<li>溶離液として 1.5 cm クロマトグラフィー コラムと 1:4 酢酸エチル/ヘキサン シリカゲル カラムクロマトグラフィーにより粗製品を浄化します。イミダートの物理的な形を分子から分子へと変わります。</li>
</ol><img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56610/56610fig1v3.jpg"> 図 1.2 アジドフェニル 1 硝酸エステルの 2 アジドフェニル-1 trichloroimidates への 1 つの鍋変換の代表的な例です。<a href="//cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56610/56610fig1v3large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。

<ol>
	<li>Nicolaou, K. C., Mitchell, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adventures+in+Carbohydrate+Chemistry:+New+Synthetic+Technologies,+Chemical+Synthesis,+Molecular+Design,+and+Chemical+Biology+A+list+of+abbreviations+can+be+found+at+the+end+of+this+article.+Telemachos+Charalambous+was+an+inspiring+teacher+at+the+Pancyprian+Gymnasium,+Nicosia,+Cyprus.">Adventures in Carbohydrate Chemistry: New Synthetic Technologies, Chemical Synthesis, Molecular Design, and Chemical Biology A list of abbreviations can be found at the end of this article. Telemachos Charalambous was an inspiring teacher at the Pancyprian Gymnasium, Nicosia, Cyprus.</a> Angew. Chem. Int. Ed. Engl. 40 (9), 1576-1624 (2001).</li><li>Danishefsky, S. J., Allen, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+the+laboratory+to+the+clinic:+A+retrospective+on+fully+synthetic+carbohydrate-based+anticancer+vaccines.">From the laboratory to the clinic: A retrospective on fully synthetic carbohydrate-based anticancer vaccines.</a> Angew. Chem. Int. Ed. Engl. 39 (5), 836-863 (2000).</li><li>Nicolaou, K. C., Hale, C. R. H., Nilewski, C., Ioannidou, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Constructing+molecular+complexity+and+diversity:+total+synthesis+of+natural+products+of+biological+and+medicinal+importance.">Constructing molecular complexity and diversity: total synthesis of natural products of biological and medicinal importance.</a> Chemical Society Reviews. 41 (15), 5185-5238 (2012).</li><li>Zhu, X., Schmidt, R. 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+principles+for+glycoside-bond+formation.">New principles for glycoside-bond formation.</a> Angew. Chem. Int. Ed. Engl. 48 (11), 1900-1934 (2009).</li><li>Danishefsky, S. J., Bilodeau, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glycals+in+organic+synthesis:+The+evolution+of+comprehensive+strategies+for+the+assembly+of+oligosaccharides+and+glycoconjugates+of+biological+consequence.">Glycals in organic synthesis: The evolution of comprehensive strategies for the assembly of oligosaccharides and glycoconjugates of biological consequence.</a> Angew. Chem. Int. Ed. Engl. 35 (13-14), 1380-1419 (1996).</li><li>Bongat, A. F., Demchenko, A. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+trends+in+the+synthesis+of+O-glycosides+of+2-amino-2-deoxysugars.">Recent trends in the synthesis of O-glycosides of 2-amino-2-deoxysugars.</a> Carbohydr. Res. 342 (3-4), 374-406 (2007).</li><li>Feizi, T., Fazio, F., Chai, W. C., Wong, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbohydrate+microarrays+-+a+new+set+of+technologies+at+the+frontiers+of+glycomics.">Carbohydrate microarrays - a new set of technologies at the frontiers of glycomics.</a> Curr. Opin. Struct. Biol. 13 (5), 637-645 (2003).</li><li>Palmacci, E. R., Plante, O. J., Seeberger, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oligosaccharide+synthesis+in+solution+and+on+solid+support+with+glycosyl+phosphates.">Oligosaccharide synthesis in solution and on solid support with glycosyl phosphates.</a> Eur. J. Org. Chem. (4), 595-606 (2002).</li><li>Stallforth, P., Lepenies, B., Adibekian, A., Seeberger, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=2009+Claude+S.+Hudson+Award+in+Carbohydrate+Chemistry.+Carbohydrates:+a+frontier+in+medicinal+chemistry.">2009 Claude S. Hudson Award in Carbohydrate Chemistry. Carbohydrates: a frontier in medicinal chemistry.</a> J. Med. Chem. 52 (18), 5561-5577 (2009).</li><li>Danishefsky, S. J., Mcclure, K. F., Randolph, J. T., Ruggeri, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Strategy+for+the+Solid-Phase+Synthesis+of+Oligosaccharides.">A Strategy for the Solid-Phase Synthesis of Oligosaccharides.</a> Science. 260 (5112), 1307-1309 (1993).</li><li>Demchenko, A. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stereoselective+chemical+1,2-cis+O-glycosylation:+From+'sugar+ray'+to+modern+techniques+of+the+21st+century.">Stereoselective chemical 1,2-cis O-glycosylation: From 'sugar ray' to modern techniques of the 21st century.</a> Synlett. (9), 1225-1240 (2003).</li><li>Fraserreid, B., Wu, Z. F., Udodong, U. E., Ottosson, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Armed-Disarmed+Effects+in+Glycosyl+Donors+-+Rationalization+and+Sidetracking.">Armed-Disarmed Effects in Glycosyl Donors - Rationalization and Sidetracking.</a> J. Org. Chem. 55 (25), 6068-6070 (1990).</li><li>Bohe, L., Crich, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+propos+of+glycosyl+cations+and+the+mechanism+of+chemical+glycosylation;+the+current+state+of+the+art.">A propos of glycosyl cations and the mechanism of chemical glycosylation; the current state of the art.</a> Carbohydr. Res. 403, 48-59 (2015).</li><li>Toshima, K., Tatsuta, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+Progress+in+O-Glycosylation+Methods+and+Its+Application+to+Natural-Products+Synthesis.">Recent Progress in O-Glycosylation Methods and Its Application to Natural-Products Synthesis.</a> Chem. Rev. 93 (4), 1503-1531 (1993).</li><li>Koenigs, W., Knorr, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ueber+einige+Derivate+des+Traubenzuckers+und+der+Galactose.">Ueber einige Derivate des Traubenzuckers und der Galactose.</a> Chem. Ber. 34 (1), 957-981 (1901).</li><li>Mukaiyama, T., Murai, Y., Shoda, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Efficient+Method+for+Glucosylation+of+Hydroxy+Compounds+Using+Glucopyranosyl+Fluoride.">An Efficient Method for Glucosylation of Hydroxy Compounds Using Glucopyranosyl Fluoride.</a> Chem. Lett. (3), 431-432 (1981).</li><li>Meloncelli, P. J., Martin, A. D., Lowary, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glycosyl+iodides.+History+and+recent+advances.">Glycosyl iodides. History and recent advances.</a> Carbohydrate Research. 344 (9), 1110-1122 (2009).</li><li>Lian, G., Zhang, X., Yu, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thioglycosides+in+carbohydrate+research.">Thioglycosides in carbohydrate research.</a> Carbohydr. Res. 403, 13-22 (2015).</li><li>Schmidt, R. R., Kinzy, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anomeric-Oxygen+Activation+for+Glycoside+Synthesis+-+the+Trichloroacetimidate+Method.">Anomeric-Oxygen Activation for Glycoside Synthesis - the Trichloroacetimidate Method.</a> Advances in Carbohydrate Chemistry and Biochemistry. 50, 21-123 (1994).</li><li>Schmidt, R. R., Toepfer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glycosylation+with+highly+reactive+glycosyl+donors:+efficiency+of+the+inverse+procedure.">Glycosylation with highly reactive glycosyl donors: efficiency of the inverse procedure.</a> Tetrahedron Lett. 32 (28), 3353-3356 (1991).</li><li>Keith, D. J., Townsend, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct,+microwave-assisted+substitution+of+anomeric+nitrate-esters.">Direct, microwave-assisted substitution of anomeric nitrate-esters.</a> Carbohydr. Res. 442, 20-24 (2017).</li><li>Bukowski, 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=Synthesis+and+Conformational+Analysis+of+the+T-Antigen+Disaccharide(B-D-Gal-(1->3)-a-D-GalNAc-OMe).">Synthesis and Conformational Analysis of the T-Antigen Disaccharide(B-D-Gal-(1->3)-a-D-GalNAc-OMe).</a> Eur. J. Org. Chem. 14, 2697-2705 (2001).</li></ol>

著者は競合する金融興味を持ってないです。

このチュートリアルで説明されているプロトコルは、反応性、役に立つ機能を硝酸エステルに変換するメソッドを提供します。広い意味で安易な日常難しい変換をする可能性があります炭水化物の合成の過程で特定の演習を完了するマイクロ波リアクターを採用します。このチュートリアルで私たちの目標は、マイクロ波照射のコンテキストで炭水化物を処理する方法を示すことです。
親の反応の場合脱硝を達成するために以前の努力は通常強く求核試薬との反応時間が延長されたに頼ってきました。ここ記載されている技術の強みは、電子レンジがアノマー硝酸エステルの定量操作を可能にする非常に短い間隔でハイパワー暖房を提供することです。C2 の構成糖である化合物のメソッドに最適、これまでこの位置で「赤道」アルコールすなわち。C2 での「軸」のマンノースの構成を特色にする化合物は、彼らは耐加水分解性の長期照射を受ける必要があります。酸ではない分子基盤を除くことができる・ デ ・ ニトロ化で生成される酸を隔離する存在下での反応が行われている間不安定。また、反応 (すなわち peracetylated 糖) に耐性のある分子を加水分解する反応時間を増加できます。浄化に関して、マイクロ波反応後生産アルコールを浄化できます。

分子生物学の彼らの普及のため、炭水化物は化学合成の長年の目標をされています。1,2,3合成キャンペーンの成功の中核となる糖鎖を構築するグリコシル化反応の正しい展開です。4,5,6,7,8,9,10,11,12当然、グリコシド結合をインストールする方法の大きい数があります。13,14 Koenigs クノール メソッドは最も早く知られている手順の 1 つですし、結合糖塩化または臭化通常重金属 (水銀や銀) 活性化の下でのアルコール成分が含まれます。15関連糖フッ化物向山グループの 1981 年にドナーとして初めて導入され、彼らの高められた熱・化学安定性のための広範なアプリケーションを発見しました。16反応スペクトルの反対側に糖ヨウ化物、他のハロゲン化物よりもはるかに反応であります。特に α 結合型糖鎖形成増加の立体制御反応性が伴っています。17 "haloglycosides"に加えチオグリコシドを発見したワイドなユーティリティ、一部、形成、反応条件と求電子試薬の活性化の多数の安定性の容易にするため。18
上記フォーカス活性化およびアクセプター分子からアルコールによって最終的に転置されているグループを残して潜在的な「非酸素」を含むにアノマー アルコールに変換するメソッド。アノマー酸素活性化シュミット学校で記述として C1 酸素自体を残してグループに変換するのに焦点を当てください。19このメソッドは、最も強力なは、広く化学グリコシル化反応で。Trichloroacetimidate ドナーは、還元糖、炭酸カリウム (K2CO3) または 1, 8-diazabicyclo [5.4.0] undec-7-エン (DBU) などの塩基の存在下で trichloroacetonitrile から容易に用意しています。これらの種は、ルイス酸を用いたアクティブ化されます。20
最近では、我々 は 2 アジドフェニル-1 trichloroacetimidate ドナーがグリカールから直接調製することができますを報告しています。プロセスには、2 つの反応、2 アジドフェニル 1 硝酸エステルからプロシージャを 1 つの鍋が含まれます。21この詳細なプロトコルは、正常に高収率で変換を完了するために専門家を支援するものです。特定の関心の下で電子レンジの熱脱硝焦点を当てて補助暖房のシーケンスの最初のステップです。また有機合成におけるマイクロ波反応を採用にビジュアル チュートリアルを提供してまいります。

<table>
	<tbody>
		<tr>
			<td>230 400 mesh silica gel</td>
			<td>SiliCycle Inc</td>
			<td>R10030B</td>
			<td></td>
		</tr>
		<tr>
			<td>TLC plates</td>
			<td>SiliCycle Inc</td>
			<td>TLG-R10014B-527</td>
			<td></td>
		</tr>
		<tr>
			<td>Ceric ammonium molybdate</td>
			<td>Sigma-Aldrich</td>
			<td>A1343</td>
			<td></td>
		</tr>
		<tr>
			<td>Solvent Still</td>
			<td>Mbraun</td>
			<td>MB-SPS-800</td>
			<td></td>
		</tr>
		<tr>
			<td>Infared spectrometer</td>
			<td>Thermo</td>
			<td>Thermo Electron IR100</td>
			<td></td>
		</tr>
		<tr>
			<td>Nuclear Magnetic Resonance</td>
			<td>Bruker</td>
			<td></td>
			<td>400, 600 MHz</td>
		</tr>
		<tr>
			<td>LC/MS</td>
			<td>Thermo/Dionex</td>
			<td></td>
			<td>Single quad, ESI</td>
		</tr>
		<tr>
			<td>HRMS</td>
			<td>Agilent</td>
			<td>Synapt G2 S HDMS</td>
			<td></td>
		</tr>
		<tr>
			<td>Microwave reactor</td>
			<td>Anton Parr</td>
			<td>Anton Parr G10 Monowave 200</td>
			<td></td>
		</tr>
		<tr>
			<td>DBU</td>
			<td>Sigma-Aldrich</td>
			<td>139009</td>
			<td></td>
		</tr>
		<tr>
			<td>CCl3CN</td>
			<td>Sigma-Aldrich</td>
			<td>T53805</td>
			<td></td>
		</tr>
		<tr>
			<td>Pyridine</td>
			<td>Sigma-Aldrich</td>
			<td>270970</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Fisher Scientific</td>
			<td>A18-20</td>
			<td>Tech. grade</td>
		</tr>
		<tr>
			<td>Phase separator</td>
			<td>Biotage</td>
			<td>120-1901-A</td>
			<td></td>
		</tr>
		<tr>
			<td>Rotary evaporator</td>
			<td>Buchi</td>
			<td>R-100</td>
			<td></td>
		</tr>
	</tbody>
</table>

one-pot microwave-assisted conversion of anomeric nitrate-esters to trichloroacetimidates

次の手順の目的は、2-アジドフェニル-1-硝酸-エステルの trichloroacetimidate 糖ドナーへの 1 つの鍋変換のデモを提供することです。アジドフェニル-、glycal のニトロ化、次、マイクロ波照射下で製品 2 アジドフェニル 1 硝酸エステルを加水分解することができます。この変換では、強く求核試薬との反応時間が延長された使用は行われます通常。マイクロ波照射は、試薬と短い反応時間の不在で、加水分解を誘導します。次の脱硝、中間アノマー アルコールは、対応する 2-アジドフェニル-1-trichloroacetimidate に、同じ鍋に変換されます。

3 2 アジドフェニル 1 硝酸エステルのプールに記載の技術を示した。それぞれのケースで反応の最初のステップは、20 分以内で完了しました。
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56610/56610fig2v3.jpg"> 図 2 。加水分解の代表例 (1 -2)、および1の 2 アジドフェニル 1 硝酸エステルのワンポット変換 (1-3)。<a href="//cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56610/56610fig2v3large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
(2S,3R,4S,5S,6R)-2-(((2R,3S,4R,5R,6R)-4-acetoxy-2-(acetoxymethyl)-5-azido-6-(imino(2l3-trichloran-2-yl)methoxy)tetrahydro-2H-pyran-3-yl)oxy)-6-(acetoxymethyl)tetrahydro-2H-pyran-3,4,5-triyl アセテート (3)11 の混合物: 1:6 (アルファまんのう-/アルファに関する-/ベータ版に関する-) 構成されている azidonitrate エステル1 (1.0 当量, 0.133 g, 0.20 mmol) 20% アセトン (2.0 mL) に溶解し、ピリジン (5.0 当量、1.0 ミリ モル、0.8 mL) と扱われます。反応は、10 分の 120 ° C にマイクロ波によって加熱されました。次に、反応混合物を 0 ° C に冷却し、CH2Cl2 (1.0 mL) と扱われます。反応の水層を除去します。その後、反応は DBU (10 当量、0.3 mL、1.9 ミリ モル) と 2,2,2 trichloroacetonitrile (50 当量、1.0 mL、10 m モル) を追加しました。15反応は、rt にウォーム アップをさせて頂きました。出発原料の完全な消費の後混合物は集中して真空中であった。フラッシュ クロマトグラフィーによって精製された原油 (10:3 - 1:1 ヘキサン/エチル) 5:1 を与える (に関する-/満濃-) アルファ イミダート製品3 (0.133 g、0.174 モル、全体の 87%) の混合物。これらの反応条件下でまんのう - 構成開始材料は前述の加水分解に強いです。この反応で > に関する-構成されている原料の 95% が正常に、満濃の 62% アルファ イミダート 3 に変換-構成された原料はイミダート製品に変換されました。分光データは、以前に報告されたデータ21に同意しました。複雑な C-2 異性体の混合物として: 1H NMR (400 MHz、CDCl3) δ (s, 1 H)、8.64 6.46 (d、 J = 3.6 Hz、1 H) 5.54、(m、 J = 9.6 Hz) 5.33、(d、 J = 3.6 Hz)、5.11 (dd、 J = 10.6 Hz、 J = 7.9 Hz)、5.04 (dd, J= 3.6 Hz 9.6)、4.93 (dd、 J = 10.6, 3.6 Hz、1 H)、4.49 (d、 J = 7.9 Hz、1 H)、4.48 (m, 1 H)、4.10 (m, 4 H)、3.85 (m, 2 H)、2.14 (s, 3 H)、(s, 3 H) 2.09、2.06 (s, 3 H)、2.02 (s、6 H)、1.99 (s, 3 H)、1.95 (s, 3 H);13C NMR (100 MHz、CDCl3) δ 同期比 171.2、170.4, 170.2、170.1、169.4、169.2、対し 169.0、162.1、101.3、92.9、76.6、71.2、70.9、70.8、69.8, 69.5、69.2、66.7、61.5、60.8、21.1、21.0、20.7、20.6。
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/56610/56610fig3v3.jpg"> 図 3.加水分解の代表例 (4 →5)、および4の 2 アジドフェニル 1 硝酸エステルの変換を 1 つの鍋 (4→6)。<a href="//cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56610/56610fig3v3large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
((3aR,4R,7R,7aR)-7-azido-6-hydroxy-2,2-dimethyltetrahydro-4H-[1,3]dioxolo[4,5-c]pyran-4-yl)methyl 酢酸 (6)。Azidonitrate エステル4 (1.0 当量、0.451 モル 0.150 g 1:4 水/アセトン (4.0 mL) と (5.0 当量、0.18 mL、2.26 モル) ピリジン溶液で) は、10 分の 110 ° C にマイクロ波照射によって加熱されました。その後、反応はバイアルは、最初のボリューム ~1/2 に溶剤の混合物を減らすために空気の流れの下で濃縮しました。粗反応混合物は、CH2Cl2 (4.0 mL) を追加しました。反応の水層を除去します。その後、反応されました DBU (2.0 当量、0.14 mL、0.90 モル) と 2,2,2 trichloroacetonitrile (10 当量、0.45 mL、4.51 mmol) 0 ° C で30 分で反応は暗い茶色の原油に集中していた。原油の漏斗フィルターのシリカゲルのプラグを通過し、集中して、フラッシュ ・ クロマトグラフィー (2:5 エチル/ヘキサン) 34: 1 混合物 (アルファ/ベータ版) イミダート6を与えることによって浄化 (0.189 g、0.438 モル、> 95%) 黄色の油として。分光データは、以前に報告されたデータ21に同意しました。Rƒ 0.26 (1:3 エチル/ヘキサン);[Α]D20 +6.63 ° (c 0.3, CHCl3);IR (薄膜、cm 1) 3943.02、3689.98、3053.89、2986.53、2684.50、2409.92、2304.81、2115.20、1735.63、1674.77、1616.82、1421.56、1265.14、741.47、705.37。1 H NMR (400 MHz、CDCl3): α アノマー δ8.75 (s, 1 H)、6.34 (d、J = 3.4 Hz、1 H)、4.48 (dd、1 H、J 5.5 7.9 Hz、1 H =)、4.44-4.24 (m, 4 H)、3.76 (dd、J 3.4, 7.7 Hz、1 H =)、2.04 (s, 3 H)、(s, 3 H) 1.54、1.36 (s, 3 H);13 C (100 MHz、CDCl3): δ170.69、94.34、90.67、73.35、72.32、68.13、63.13 110.54、160.47 60.11、27.92、26.00、20.75;HRQ-飛行時間型質量 (m/z): [m+Na] calcd+C13H17Cl3N4O6453.0111、453.1277 を発見しました。
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/56610/56610fig4v3.jpg"> 図 4 。加水分解の代表例 (7 →8)、および7の 2 アジドフェニル 1 硝酸エステルのワンポット変換 (7→9)。<a href="//cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56610/56610fig4v3large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
2R,3S,4R,5R,6R)-2-(acetoxymethyl)-5-azido-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4-diyl ジアセテートと (2R,3S,4R,5S,6R)-2-(acetoxymethyl)-5-azido-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4-diylジアセテート (9)。1:14.4:27.4 (ベータ版に関する - アルファ/満濃-/アルファに関する-) アセテート7 (1.0 当量、1.164 モル 0.438 g 1:4 水/アセトン (10.0 mL) とピリジン (5.0 当量、0.47 mL、5.82 mmol) の溶液中) の混合物が 20 の 120 ° C でマイクロ波照射による加熱しました。分。その後、反応のバイアルは、最初のボリュームの ~1/2 に混合溶媒の量を減らすために空気の流れの下で集中していた。粗反応混合物は、CH2Cl2 (10.0 mL) を追加しました。反応の水層を除去します。その後、反応されました DBU (1.0 当量、0.18 mL、1.164 モル) と 2,2,2 trichloroacetonitrile (10 当量、1.2 mL、11.64 モル) 0 ° C で1 h で、反応は薄いオレンジと pH の反応の混合物であった 7。追加 DBU (1.0 当量、0.18 mL、1.164 モル) が追加され、反応を仰いだその特徴的なダークブラウン色。3 h で、反応は暗い茶色原油に集中していた。原油は 1:1.7 に関する-を与えるフラッシュ クロマトグラフィー (2:5 エチル/ヘキサン) によって精製された/満濃 - 黄色の油としてアルファ イミダート9 (0.3758 g、0.790 ミリ モル、68%) の混合物で構成されています。分光データは、以前に報告されたデータ21に同意しました。1H NMR (400 MHz、CDCl3): 異性体の複雑な混合物として: δ 8.68 (s), 6.51 (d、 J = 3.7 Hz)、5.51 (m), 5.13 (m), 5.09 (dd、 J = 10.3、3.7 Hz)、4.24 (dd、 J = 12.0, 3.8 Hz)、4.19 4.15 (m) 4.09 (dd、 J = 12.0, 1.8 Hz)、2.02 (s)、2.00 (s), 1.98 (s), 1.97 (s);13C NMR (100 MHz、CDCl3): δ 170.5、170.0, 169.8, 169.5, 160.7、92.9、90.7、70.0、69.8、69.7、67.7、61.4、20.7、20.6, 20.5。
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/56610/56610fig5.jpg"> 図 5 。13H と13C のスペクトル。<a href="//cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56610/56610fig5large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/56610/56610fig6.jpg"> 図 6 。16H と13C のスペクトル。<a href="//cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56610/56610fig6large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/56610/56610fig7.jpg"> 図 7 。19H と13C のスペクトル。<a href="//cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56610/56610fig7large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。

Watch this Scientific Journal Video about One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates at JoVE.com

One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates

1 つの鍋マイクロ波への変換アノマー硝酸エステルの Trichloroacetimidates

2-アジドフェニル-1-硝酸のエステルは、対応する 2-アジドフェニル-1-trichloroacetimidate 1 つの鍋の手順でに変換できます。原稿の目標は、炭水化物の合成におけるマイクロ波リアクターの有用性を示すことです。

The goal of the following procedure is to provide a demonstration of the one-pot conversion of a 2-azido-1-nitrate-ester to a trichloroacetimidate ...

one-pot-microwave-assisted-conversion-anomeric-nitrate-esters-to

Nanyang Technological University

Research

JoVE Journal

Chemistry

7.4K ビュー.  Vanderbilt University. 2-アジドフェニル-1-硝酸のエステルは、対応する 2-アジドフェニル-1-trichloroacetimidate 1 つの鍋の手順でに変換できます。原稿の目標は、炭水化物の合成におけるマイクロ波リアクターの有用性を示すことです。

ビデオ: One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates

Microwave-assisted Intramolecular Dehydrogenative Diels-Alder Reactions for the Synthesis of Functionalized Naphthalenes/Solvatochromic Dyes

Functionalized naphthalenes have applications in a variety of research fields ranging from the synthesis of natural or biologically active molecules to the preparation of new organic dyes. Although numerous strategies have been reported to access naphthalene scaffolds, many procedures still present limitations in terms of incorporating functionality, which in turn narrows the range of available substrates. The development of versatile methods for direct access to substituted naphthalenes is therefore highly desirable.
The Diels-Alder (DA) cycloaddition reaction is a powerful and attractive method for the formation of saturated and unsaturated ring systems from readily available starting materials. A new microwave-assisted intramolecular dehydrogenative DA reaction of styrenyl derivatives described herein generates a variety of functionalized cyclopenta[b]naphthalenes that could not be prepared using existing synthetic methods. When compared to conventional heating, microwave irradiation accelerates reaction rates, enhances yields, and limits the formation of undesired byproducts.
The utility of this protocol is further demonstrated by the conversion of a DA cycloadduct into a novel solvatochromic fluorescent dye via a Buchwald-Hartwig palladium-catalyzed cross-coupling reaction. Fluorescence spectroscopy, as an informative and sensitive analytical technique, plays a key role in research fields including environmental science, medicine, pharmacology, and cellular biology. Access to a variety of new organic fluorophores provided by the microwave-assisted dehydrogenative DA reaction allows for further advancement in these fields.

Microwave-assisted intramolecular dehydrogenative Diels-Alder (DA) reactions provide concise access to functionalized cyclopenta[b]naphthalene building blocks. The utility of this methodology is demonstrated by one-step conversion of the dehydrogenative DA cycloadducts into novel solvatochromic fluorescent dyes via Buchwald-Hartwig palladium-catalyzed cross-coupling reactions.

官能ナフタレン/ソルバトクロミック色素の合成のためのマイクロ波支援分子内脱水素Diels-Alder反応

Functionalized naphthalenes have applications in a variety of research fields ranging from the synthesis of natural or biologically active molecules to ...

化学

Microwave-assisted Functionalization of Poly(ethylene glycol) and On-resin Peptides for Use in Chain Polymerizations and Hydrogel Formation

One of the main benefits to using poly(ethylene glycol) (PEG) macromers in hydrogel formation is synthetic versatility. The ability to draw from a large variety of PEG molecular weights and configurations (arm number, arm length, and branching pattern) affords researchers tight control over resulting hydrogel structures and properties, including Young&#8217;s modulus and mesh size. This video will illustrate a rapid, efficient, solvent-free, microwave-assisted method to methacrylate PEG precursors into poly(ethylene glycol) dimethacrylate (PEGDM). This synthetic method provides much-needed starting materials for applications in drug delivery and regenerative medicine. The demonstrated method is superior to traditional methacrylation methods as it is significantly faster and simpler, as well as more economical and environmentally friendly, using smaller amounts of reagents and solvents. We will also demonstrate an adaptation of this technique for on-resin methacrylamide functionalization of peptides. This on-resin method allows the N-terminus of peptides to be functionalized with methacrylamide groups prior to deprotection and cleavage from resin. This allows for selective addition of methacrylamide groups to the N-termini of the peptides while amino acids with reactive side groups (e.g.&#160;primary amine of lysine, primary alcohol of serine, secondary alcohols of threonine, and phenol of tyrosine) remain protected, preventing functionalization at multiple sites. This article will detail common analytical methods (proton Nuclear Magnetic Resonance spectroscopy (;H-NMR) and Matrix Assisted Laser Desorption Ionization Time of Flight mass spectrometry (MALDI-ToF)) to assess the efficiency of the functionalizations. Common pitfalls and suggested troubleshooting methods will be addressed, as will modifications of the technique which can be used to further tune macromer functionality and resulting hydrogel physical and chemical properties. Use of synthesized products for the formation of hydrogels for drug delivery and cell-material interaction studies will be demonstrated, with particular attention paid to modifying hydrogel composition to affect mesh size, controlling hydrogel stiffness and drug release.

Microwave-assisted Functionalization of Polyethylene glycol and On-resin Peptides for Use in Chain Polymerizations and Hydrogel Formation

This video will illustrate a rapid, efficient method to methacrylate poly(ethylene glycol), enabling chain polymerizations and hydrogel synthesis. It will demonstrate how to similarly introduce methacrylamide functionalities into peptides, detail common analytical methods to assess functionalization efficiency, provide suggestions for troubleshooting and advanced modifications, and demonstrate typical hydrogel characterization techniques.

マイクロ波支援ポリの機能化（エチレングリコール）と連鎖重合で使用するためには樹脂ペプチドおよびヒドロゲル形成

One of the main benefits to using poly(ethylene glycol) (PEG) macromers in hydrogel formation is synthetic versatility. The ability to draw from a large ...

Preparation of Silica Nanoparticles Through Microwave-assisted Acid-catalysis

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle diameters ranging from 30-250 nm by varying the reaction conditions. Through the selection of a microwave compatible solvent, silicic acid precursor, catalyst, and microwave irradiation time, these microwave-assisted methods were capable of overcoming the previously reported shortcomings associated with synthesis of silica nanoparticles using microwave reactors. The siloxane precursor was hydrolyzed using the acid catalyst, HCl. Acetone, a low-tan &#948; solvent, mediates the condensation reactions and has minimal interaction with the electromagnetic field. Condensation reactions begin when the silicic acid precursor couples with the microwave radiation, leading to silica nanoparticle sol formation. The silica nanoparticles were characterized by dynamic light scattering data and scanning electron microscopy, which show the materials&#39; morphology and size to be dependent on the reaction conditions. Microwave-assisted reactions produce silica nanoparticles with roughened textured surfaces that are atypical for silica sols produced by St&#246;ber&#39;s methods, which have smooth surfaces.

Silica nanoparticles were prepared using acid-catalysis of a siloxane precursor and microwave-assisted synthetic techniques resulting in the controlled growth of nanomaterials ranging from 30-250 nm in diameter. The growth dynamics can be controlled by varying the initial silicic acid concentration, time of the reaction, and temperature of reaction.

マイクロ波支援酸 - 触媒反応によりシリカナノ粒子の調製

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle ...

Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

Decomposition of N-tosyl-1,2,3-triazoles with rhodium(II) acetate dimer in the presence of alcohols forms synthetically versatile N-(2-alkoxyvinyl)sulfonamides, which react under a variety of conditions to afford useful N- and O-containing compounds. Acid-catalyzed addition of alcohols or thiols to N-(2-alkoxyvinyl)sulfonamide-containing phthalans provides access to ketals and thioketals, respectively. Selective reduction of the vinyl group in N-(2-alkoxyvinyl)sulfonamide-containing phthalans via hydrogenation yields the corresponding phthalan in good yield, whereas reduction with sodium bis(2-methoxyethoxy)aluminumhydride generates a ring-opened phenethylamine analogue. Because the N-(2-alkoxyvinyl)sulfonamide functional group is synthetically versatile, but often hydrolytically unstable, this protocol emphasizes key techniques in preparing, handling, and reacting these pivotal substrates in several useful transformations.

Preparation of N-2-alkoxyvinylsulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

Representative experimental procedures for the synthesis of N-(2-alkoxyvinyl)sulfonamides and subsequent conversion to phthalan and phenethylamine derivatives are presented in detail.

Nの準備-(2-alkoxyvinyl) N- トシル-1,2,3-トリアゾールと置換 Phthalans とフェネチルアミンに後続の変換からサルファ剤

Decomposition of N-tosyl-1,2,3-triazoles with rhodium(II) acetate dimer in the presence of alcohols forms synthetically versatile ...

Reducing Willow Wood Fuel Emission by Low Temperature Microwave Assisted Hydrothermal Carbonization

Biomass is a sustainable fuel, as its CO2 emissions are reintegrated in biomass growth. However, the inorganic precursors in the biomass cause a negative environmental impact and slag formation. The selected short rotation coppice (SRC) willow wood has a high ash content (<img alt="Equation 1" src="/files/ftp_upload/58970/58970eq1.jpg" /> = 1.96%) and, therefore, a high content of emission and slag precursors. Therefore, the reduction of minerals from SRC willow wood by low temperature microwave assisted hydrothermal carbonization (MAHC) at 150 &#176;C, 170 &#176;C, and 185 &#176;C is investigated. An advantage of MAHC over conventional reactors is an even temperature conductance in the reaction medium, as microwaves penetrate the whole reactor volume. This allows a better temperature control and a faster cooldown. Therefore, a succession of depolymerization, transformation and repolymerization reactions can be analyzed effectively. In this study, the analysis of the mass loss, ash content and composition, heating values and molar O/C and H/C ratios of the treated and untreated SCR willow wood showed that the mineral content of the MAHC coal was reduced and the heating value increased. The process water showed a decreasing pH and contained furfural and 5-methylfurfural. A process temperature of 170 &#176;C showed the best combination of energy input and ash component reduction. The MAHC allows a better understanding of the hydrothermal carbonization process, while a large-scale industrial application is unlikely because of the high investment costs.

A protocol for the emission precursor depletion from low quality biomass by low temperature microwave assisted hydrothermal carbonization treatment is presented. This protocol includes the microwave parameters and the analysis of the biocoal product and process water.

低温マイクロ波支援によるウィローウッド燃料排出量の削減補助熱炭化

Biomass is a sustainable fuel, as its CO2 emissions are reintegrated in biomass growth. However, the inorganic precursors in the biomass cause a negative ...

Synthesis of In37P20(O2CR)51 Clusters and Their Conversion to InP Quantum Dots

This text presents a method for the synthesis of In37P20(O2C14H27)51 clusters and their conversion to indium phosphide quantum dots. The In37P20(O2CR)51 clusters have been observed as intermediates in the synthesis of InP quantum dots from molecular precursors (In(O2CR)3, HO2CR, and P(SiMe3)3) and may be isolated as a pure reagent for subsequent study and use as a single-source precursor. These clusters readily convert to crystalline and relatively monodisperse samples of quasi-spherical InP quantum dots when subjected to thermolysis conditions in the absence of additional precursors above 200 &#176;C. The optical properties, morphology, and structure of both the clusters and quantum dots are confirmed using UV-Vis spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, and powder X-ray diffraction. The molecular symmetry of the clusters is additionally confirmed by solution-phase 31P NMR spectroscopy. This protocol demonstrates the preparation and isolation of atomically-precise InP clusters, and their reliable and scalable conversion to InP QDs.

Synthesis of In37P20O2CR51 Clusters and Their Conversion to InP Quantum Dots

A protocol for the synthesis of In37P20(O2C14H27)51 clusters and their conversion to indium phosphide quantum dots is presented.

37P20(o2 CR)51クラスターの合成と InP 量子ドットへの変換

This text presents a method for the synthesis of In37P20(O2C14H27)51 clusters and their conversion to indium phosphide quantum dots. The In37P20(O2CR)51 ...

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

A synthetic process for the preparation of a variety of 1-aryl-1H-pyrazole-5-amines was developed. The microwave-mediated nature of this method makes it efficient in both time and resources and utilizes water as the solvent. 3-Aminocrotononitrile or an appropriate &#945;-cyanoketone is combined with an aryl hydrazine and dissolved in 1 M HCl. The mixture is then heated in a microwave reactor at 150 &#176;C, typically for 10-15 min. The product can be readily obtained by basifying the solution with 10% NaOH and isolating the desired compound with a simple vacuum filtration. The use of water as a solvent in this reaction lends to its ease and utility in production, and this method is easily reproducible with a variety of functional groups. Typical isolated yields range from 70-90%, and reactions can be performed on the milligram to gram scale with little to no change in observed yields. Some of the applications of these molecules and their derivatives include pesticides, anti-malarials, and chemotherapeutics, among many others.

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

1-Aryl-1H-pyrazole-5-amines are prepared from aryl hydrazines combined with either 3-aminocrotononitrile or an &#945;-cyanoketone in a 1 M HCl solution using a microwave reactor. Most reactions are done in 10-15 minutes and pure product can be obtained via vacuum filtration with typical isolated yields of 70-90%.

1-アリル-1 H-ピラゾール-5-アミンのマイクロ波支援調製

A synthetic process for the preparation of a variety of 1-aryl-1H-pyrazole-5-amines was developed. The microwave-mediated nature of this method makes it ...

Hierarchical and Programmable One-Pot Oligosaccharide Synthesis

This article presents a general experimental protocol for programmable one-pot oligosaccharide synthesis and demonstrates how to use Auto-CHO software for generating potential synthetic solutions. The programmable one-pot oligosaccharide synthesis approach is designed to empower fast oligosaccharide synthesis of large amounts using thioglycoside building blocks (BBLs) with the appropriate sequential order of relative reactivity values (RRVs). Auto-CHO is a cross-platform software with a graphical user interface that provides possible synthetic solutions for programmable one-pot oligosaccharide synthesis by searching a BBL library (containing about 150 validated and &#62;50,000 virtual BBLs) with accurately predicted RRVs by support vector regression. The algorithm for hierarchical one-pot synthesis has been implemented in Auto-CHO and uses fragments generated by one-pot reactions as new BBLs. In addition, Auto-CHO allows users to give feedback for virtual BBLs to keep valuable ones for further use. One-pot synthesis of stage-specific embryonic antigen 4 (SSEA-4), which is a pluripotent human embryonic stem cell marker, is demonstrated in this work.

This protocol demonstrates how to use the Auto-CHO software for hierarchical and programmable one-pot synthesis of oligosaccharides. It also describes the general procedure for RRV determination&#160;experiments and one-pot glycosylation of SSEA-4.

階層的でプログラム可能なワンポットオリゴ糖合成

This article presents a general experimental protocol for programmable one-pot oligosaccharide synthesis and demonstrates how to use Auto-CHO software for ...

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

CO2 transformations using a one-pot two-step method are presented herein. The purpose of the method is to give access to a variety of value-added products and notably to generate chiral carbon centers. The crucial first step consists in the selective double hydroboration of CO2 catalyzed by an iron hydride complex. The product obtained with this 4 e- reduction is a rare bis(boryl)acetal, compound 1, which is subjected in situ to three different reactions in a second step. The first reaction concerns a condensation reaction with (diisopropyl)phenylamine affording the corresponding imine 2. In the second and third reaction, intermediate 1 reacts with triazol-5-ylidene (Enders&#39; carbene) to afford compounds 3 or 4, depending on the reaction conditions. In both compounds, C-C bonds are formed, and chiral centers are generated from CO2 as the only source of carbon. Compound 4 exhibits two chiral centers obtained in a diastereoselective manner in a formose-type mechanism. We proved that the remaining boryl fragment plays a key role in this unprecedented stereocontrol. The interest of the method stands on the reactive and versatile nature of 1, giving rise to various complex molecules from a single intermediate. The complexity of a two-step method is compensated by the overall short reaction time (2 h for the larger reaction time), and mild reaction conditions (25 &#176;C to 80 &#176;C and 1 to 3 atm of CO2).

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

CO2 transformations are conducted in a one-pot two-step procedure for the synthesis of complex molecules. The selective 4 e- reduction of CO2 with a hydroborane reductant affords a reactive and versatile bis(boryl)acetal intermediate which is subsequently involved in condensation reaction or carbene-mediated C-C coupling generation.

多彩なCO2の複雑な製品への変革:ワンポット2段階戦略

CO2 transformations using a one-pot two-step method are presented herein. The purpose of the method is to give access to a variety of value-added products ...

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Heteroarylation introduces heteroaryl fragments to organic molecules. Despite the numerous available reactions reported for arylation via transition metal catalysis, the literature on direct heteroarylation is scarce. The presence of heteroatoms such as nitrogen, sulfur and oxygen often make heteroarylation a challenging research field due to catalyst poisoning, product decomposition and the rest. This protocol details a highly efficient direct &#945;-C(sp3) heteroarylation of ketones under microwave irradiation. Key factors for successful heteroarylation include the use of XPhos Palladacycle Gen. 4 Catalyst, excess base to suppress side reactions and the high temperature and pressure achieved in a sealed reaction vial under microwave irradiation. The heteroarylation compounds prepared by this method were fully characterized by proton nuclear magnetic resonance spectroscopy (1H NMR), carbon nuclear magnetic resonance spectroscopy (13C NMR) and high-resolution mass spectrometry (HRMS). This methodology has several advantages over literature precedents including broad substrate scope, rapid reaction time, greener procedure and operational simplicity by eliminating the preparation of intermediates such as silyl enol ether. Possible applications for this protocol include, but are not limited to, diversity-oriented synthesis for the discovery of biologically active small molecules, domino synthesis for the preparation of natural products and ligand development for new transition metal catalytic systems.

Heteroaryl compounds are important molecules utilized in organic synthesis, medicinal and biological chemistry. A microwave-assisted heteroarylation using palladium catalysis provides a rapid and efficient method to attach heteroaryl moieties directly to ketone substrates.

遷移金属触媒を用いたケトンのマイクロ波アシスト直接ヘテロリル化

Heteroarylation introduces heteroaryl fragments to organic molecules. Despite the numerous available reactions reported for arylation via transition metal ...