We gratefully acknowledge the Swedish Research Council Formas for generous financial support.

メチル6-オキソ3,4,6- triphenylhexanoateの1グラムスケールの合成<ol><li> 10ミリバール、1時間、40℃でロータリーエバポレーター上で丸底フラスコ中で乾燥した1-エチル-3-メチルイミダゾリウムアセテート（EMIMAc）。 </li><li> 100 mlの乾燥EMIMAc 2.1gのと1.0gの1,3-ジフェニル-2-プロペン-1-オンを追加し、マグネチックスターラーを備えた丸底フラスコ。 </li><li>フラスコにメタノールの2.019ミリリットルとシンナムアルデヒドの2.3グラムを追加します。 </li><li>室温（22℃）で1分間撹拌し、ジクロロメタン60ml中の混合物を溶解します。 </li><li>続いて攪拌混合物（ステップ1.4）に1.8 mlの0.37ジアザビシクロ[5.4.0]ウンデカ-7-エン（DBU）を追加し、丸底フラスコをキャップ。 </li><li>室温（22℃）で500回転の速度で磁気攪拌棒で攪拌します。 </li><li> 1 H-NMR。7.8 ppmの領域でカルコンの二重結合の消失のための24ルックとの反応の完了を確認してください。 </li><li>反応に達したとき<html>完成は10ミリバール、15分間20℃で回転蒸発器上で揮発性物質を除去。 </li><li>磁気撹拌棒で撹拌することによりEMIMAcを溶解残渣にメタノール50mlを追加します。 </li><li> 30分間750回転の速度で磁気攪拌棒を激しく撹拌することにより、フラスコの壁から固形物を除去します。必要に応じて、壁から残りの固形物を除去するために、スパチュラを使用しています。 </li><li>フリット（孔径3）の混合物をフィルタリングします。 </li><li>追加のメタノール20mlで洗浄します。 EMIMAcのリサイクルを希望する場合は、メタノールろ液を蒸発させます。 （ステップ2.1）。 </li><li>それでもフリットで、穏やかにスパチュラで小片に（ステップ1.11）からフィルターケーキを分割し、予め秤量した丸底フラスコに粉末漏斗を介して固体を移し、真空下で固体を乾燥させます。 </li><li>フラスコの重量を測定し、歩留まりを計算します。 </li><li> 1 H NMR（ステップ1.7）で製品を分析します。報告のスペクトルと比較してください。24 </li></ol>EMIMAcのタイトル &quot;&gt; 2。リサイクル<ol><li> 30分間40℃で、10ミリバールの減圧下で（ステップ1.12から）のメタノール混合物から揮発性物質を除去します。 </li><li> EMIMAcが存在することを確認するには、1 H NMRおよび13 C NMRによって得られた油を分析します。24 </li><li>ステップ1.2から始まるリサイクルEMIMAcを使用してください。 </li></ol> 3.ゲル化<ol><li>ストック溶液の調製<ol><li>バイアルにメチル6-オキソ3,4,6- triphenylhexanoate（ステップ1.15）からの生成物および磁気撹拌棒を200mg追加します。ケトエステルを溶解させるために2.0ミリリットルのジクロロメタンを追加します。すべてが溶解するまで撹拌します。 </li></ol></li><li>ゲル化<ol><li> 500ミリリットルのビーカーに50mlのヘプタンを追加します。ヘプタンにストック溶液1.5mlを加えます。十分な混合を確保し、ゲル化が起こるまで周囲温度で撹拌することなく放置する迅速に攪拌します。 </li></ol></li></ol>

<ol>
	<li>Hallett, J. P., Welton, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Room-Temperature+Ionic+Liquids:+Solvents+for+Synthesis+and+Catalysis.+2.">Room-Temperature Ionic Liquids: Solvents for Synthesis and Catalysis. 2.</a> Chem. Rev. 111, 3508-3576 (2011).</li><li>Welton, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Room-Temperature+Ionic+Liquids.+Solvents+for+Synthesis+and+Catalysis.">Room-Temperature Ionic Liquids. Solvents for Synthesis and Catalysis.</a> Chem. Rev. 99, 2071-2084 (1999).</li><li>Vora, H. U., Wheeler, P., Rovis, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exploiting+acyl+and+enol+azolium+intermediates+via+N-hetero-+cyclic+carbene-catalyzed+reactions+of+&#945;-reducible+aldehydes.">Exploiting acyl and enol azolium intermediates via N-hetero- cyclic carbene-catalyzed reactions of &#945;-reducible aldehydes.</a> Adv. Synth. Catal. 354, 1617-1639 (2012).</li><li>Holloczki, O., 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=Carbenes+in+ionic+liquids.">Carbenes in ionic liquids.</a> New J. Chem. 34, 3004-3009 (2010).</li><li>Enders, D., Balensiefer, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nucleophilic+Carbenes+in+Asymmetric+Organocatalysis.">Nucleophilic Carbenes in Asymmetric Organocatalysis.</a> Acc. Chem. Res. 37, 534-541 (2004).</li><li>Enders, D., Niemeier, O., Henseler, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organocatalysis+by+N-Heterocyclic+Carbenes.">Organocatalysis by N-Heterocyclic Carbenes.</a> Chem. Rev. 107, 5606-5655 (2007).</li><li>List, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enamine+Catalysis+Is+a+Powerful+Strategy+for+the+Catalytic+Generation+and+Use+of+Carbanion+Equivalents.">Enamine Catalysis Is a Powerful Strategy for the Catalytic Generation and Use of Carbanion Equivalents.</a> Acc. Chem. Res. 37, 548-557 (2004).</li><li>Nair, V., Bindu, S., Sreekumar, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=N-Heterocyclic+carbenes:+Reagents,+not+just+ligands!.">N-Heterocyclic carbenes: Reagents, not just ligands!.</a> Angew. Chem. Int. Ed. 43, 5130-5135 (2004).</li><li>Marion, N., D&#236;ez-Gonz&#225;lez, S., Nolan, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=N-Heterocyclic+Carbenes+as+Organocatalysts.">N-Heterocyclic Carbenes as Organocatalysts.</a> Angew. Chem. Int. Ed. 46, 2988-3000 (2007).</li><li>Biju, A. T., Kuhl, N., Glorius, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extending+NHC-Catalysis:+Coupling+Aldehydes+with+Unconventional+Reaction+Partners.">Extending NHC-Catalysis: Coupling Aldehydes with Unconventional Reaction Partners.</a> Acc. Chem. Res. 44, 1182-1195 (2011).</li><li>Bugaut, X., Glorius, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organocatalytic+umpolung:+N-heterocyclic+carbenes+and+beyond.">Organocatalytic umpolung: N-heterocyclic carbenes and beyond.</a> Chem. Soc. Rev. 41, 3511-3522 (2012).</li><li>Davis, h. j., Forrester, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thiazolium-ion+based+organic+ionic+liquids+(OILs).1,2+Novel+OILs+which+promote+the+benzoin+condensation.">Thiazolium-ion based organic ionic liquids (OILs).1,2 Novel OILs which promote the benzoin condensation.</a> Tetrahedron Lett. 40, 1621-1622 (1999).</li><li>Xu, L. -. W., Gao, Y., Yin, J. -. J., Li, L., Xia, C. -. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+and+mild+benzoin+condensation+reaction+catalyzed+by+simple+1-N-alkyl-3-methylimidazolium+salts.">Efficient and mild benzoin condensation reaction catalyzed by simple 1-N-alkyl-3-methylimidazolium salts.</a> Tetrahedron Lett. 46, 5317-5320 (2005).</li><li>Jiang, F. S., Yu, H., Gao, G., Xie, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benzoin+condensation+in+imidazolium+based+room-temperature+ionic+liquids.">Benzoin condensation in imidazolium based room-temperature ionic liquids.</a> Chin. Chem. Lett. 16, 321-324 (2005).</li><li>Estager, J., L&#233;v&#234;que, J. M., Turgis, R., Draye, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solventless+and+swift+benzoin+condensation+catalyzed+by+1-alkyl-3-methylimidazolium+ionic+liquids+under+microwave+irradiation.">Solventless and swift benzoin condensation catalyzed by 1-alkyl-3-methylimidazolium ionic liquids under microwave irradiation.</a> J. Mol. Catal. A: Chem. 256, 261-264 (2006).</li><li>Estager, J., L&#233;v&#234;que, J. -. M., Turgis, R., Draye, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neat+benzoin+condensation+in+recyclable+room-temperature+ionic+liquids+under+ultrasonic+activation.">Neat benzoin condensation in recyclable room-temperature ionic liquids under ultrasonic activation.</a> Tetrahedron Lett. 48, 755-759 (2007).</li><li>Orsini, M., Chiarotto, I., Elinson, M. N., Sotgiu, G., Inesi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benzoin+condensation+in+1,3-dialkylimidazolium+ionic+liquids+via+electrochemical+generation+of+N-heterocyclic+carbene.">Benzoin condensation in 1,3-dialkylimidazolium ionic liquids via electrochemical generation of N-heterocyclic carbene.</a> Electrochem. Commun. 11, 1013-1017 (2009).</li><li>Dunn, M. H., Cole, M. L., Harper, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+an+ionic+liquid+solvent+on+the+synthesis+of+[gamma]-butyrolactones+by+conjugate+addition+using+NHC+organocatalysts.">Effects of an ionic liquid solvent on the synthesis of [gamma]-butyrolactones by conjugate addition using NHC organocatalysts.</a> RSC Advances. 2, 10160-10162 (2012).</li><li>Kelemen, Z., Holloczki, O., Nagy, J., Nyulaszi, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+organocatalytic+ionic+liquid.">An organocatalytic ionic liquid.</a> Org. Biomol. Chem. 9, 5362-5364 (2011).</li><li>Yu, F. -. L., Zhang, R. -. L., Xie, C. -. X., Yu, S. -. T. <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+thermoregulated+phase-separable+triazolium+ionic+liquids+catalysts+and+application+for+Stetter+reaction.">Synthesis of thermoregulated phase-separable triazolium ionic liquids catalysts and application for Stetter reaction.</a> Tetrahedron. 66, 9145-9150 (2010).</li><li>Aupoix, A., Vo-Thanh, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solvent-free+synthesis+of+alkylthiazolium-based+ionic+liquids+and+their+use+as+catalysts+in+the+intramolecular+Stetter+reaction.">Solvent-free synthesis of alkylthiazolium-based ionic liquids and their use as catalysts in the intramolecular Stetter reaction.</a> Synlett. , 1915-1920 (2009).</li><li>Yu, F. -. L., Jiang, J. -. J., Zhao, D. -. M., Xie, C. -. X., Yu, S. -. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imidazolium+chiral+ionic+liquid+derived+carbene-catalyzed+conjugate+umpolung+for+synthesis+of+[gamma]-butyrolactones.">Imidazolium chiral ionic liquid derived carbene-catalyzed conjugate umpolung for synthesis of [gamma]-butyrolactones.</a> RSC Advances. 3, 3996-4000 (2013).</li><li>Liu, D., Zhang, Y., Chen, E. Y. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organocatalytic+upgrading+of+the+key+biorefining+building+block+by+a+catalytic+ionic+liquid+and+N-heterocyclic+carbenes.">Organocatalytic upgrading of the key biorefining building block by a catalytic ionic liquid and N-heterocyclic carbenes.</a> Green Chem. 14, 2738-2746 (2012).</li><li>Ta, L., Axelsson, A., Bijl, J., Haukka, M., Sund&#233;n, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ionic+Liquids+as+Precatalysts+in+the+Highly+Stereoselective+Conjugate+Addition+of+&#945;,&#946;-Unsaturated+Aldehydes+to+Chalcones.">Ionic Liquids as Precatalysts in the Highly Stereoselective Conjugate Addition of &#945;,&#946;-Unsaturated Aldehydes to Chalcones.</a> Chem. Eur. J. 20, 13889-13893 (2014).</li><li>Nair, V., 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=Nucleophilic+Heterocyclic+Carbene+Catalyzed+Annulation+of+Enals+to+Chalcones+in+Methanol:+A+Stereoselective+Synthesis+of+Highly+Functionalized+Cyclopentanes.">Nucleophilic Heterocyclic Carbene Catalyzed Annulation of Enals to Chalcones in Methanol: A Stereoselective Synthesis of Highly Functionalized Cyclopentanes.</a> Org. Lett. 11, 2507-2510 (2009).</li><li>Ma, J., Huang, Y., Chen, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=N-Heterocyclic+carbene-catalyzed+(NHC)+three-component+domino+reactions:+highly+stereoselective+synthesis+of+functionalized+acyclic+&#1013;-ketoesters.">N-Heterocyclic carbene-catalyzed (NHC) three-component domino reactions: highly stereoselective synthesis of functionalized acyclic &#1013;-ketoesters.</a> Org. Biomol. Chem. 9, 1791-1798 (2011).</li><li>Domingo, L. R., Saez, J. A., Arno, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+DFT+study+on+the+NHC+catalysed+Michael+addition+of+enols+to+&#945;,&#946;-unsaturated+acyl-azoliums.+A+base+catalysed+C-C+bond-formation+step.">A DFT study on the NHC catalysed Michael addition of enols to &#945;,&#946;-unsaturated acyl-azoliums. A base catalysed C-C bond-formation step.</a> Org. Biomol. Chem. 12, 895-904 (2014).</li><li>Kaeobamrung, J., Mahatthananchai, J., Zheng, P., Bode, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Enantioselective+Claisen+Rearrangement+Catalyzed+by+N-Heterocyclic+Carbenes.">An Enantioselective Claisen Rearrangement Catalyzed by N-Heterocyclic Carbenes.</a> J. Am. Chem. Soc. 132, 8810-8812 (2010).</li><li>Zweep, N., van Esch, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Functional Molecular Gels. , 1-29 (2014).</li><li>Chiang, P. -. C., Kaeobamrung, J., Bode, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enantioselective,+Cyclopentene-Forming+Annulations+via+NHC-Catalyzed+Benzoin&#8722;Oxy-Cope+Reactions.">Enantioselective, Cyclopentene-Forming Annulations via NHC-Catalyzed Benzoin&#8722;Oxy-Cope Reactions.</a> J. Am. Chem. Soc. 129, 3520-3521 (2007).</li></ol>

The authors have nothing to disclose.

ケトエステル3のX線分析およびボード線図および共同研究者30により提案されたメカニズムの調査に決定抗 -配置に基づいて、次の反応経路は、（ 図5）を提案しています。 ILの脱プロトン化は、NHC種を生成します。 NHCは、ブレスロー中間I.ザブレスロー中間体を形成する不飽和アルデヒドと反応し、カルコンはジエンIIを形成するために、クロスベンゾイン反応で?...

<img alt="目次1" src="/files/ftp_upload/53213/53213TOC.jpg" /> （上）1,6-ケトエステルの三成分合成：低分子量ゲル化剤の新しいクラス。 イオン液体（ILS）は、高安定性、低揮発性、非可燃性を有し、従って、リサイクルのための安全な反応媒体との理想的な溶剤として注目を描画している。1-3ジアルキルイミダゾリウムイオン性液体の特定のタイプであること、塩基の存在下で、N-複素環カルベン（NHC）をレンダリングするために脱プロトン化することができる。有機触媒の分野では4、NHCSは、明確な反応経路の下で動作し、一般的な反応の広い範囲に広範囲に使用を発見した。5月11日 これにもかかわらず、イオン液体およびCC結合forminとの間の接続G-NHC触媒反応は比較的未開拓です。それにもかかわらず、イオン液体由来NHCSは、ベンゾイン縮合とSTETTER反応などの反応を形成するC-C結合を触媒することが報告されている。12-22、例えば、DavisらN-アルキルthiazoliums由来のILがでプレ触媒として機能することを示しましたベンズアルデヒドからベンゾインを形成する。12 より最近では、Chenおよび共同研究者は、ILベースイミダゾリウムを使用してこの概念を拡張し、1-エチル-3-メチルイミダゾリウムアセテート（EMIMAc）、5,5 &#39;を生成するために、5-ヒドロキシメチルフルフラール（HMF）にベンゾイン縮合を行うためにジ（ヒドロキシメチル）furoin（DHMF）。23のILは、市販されており、NHCSを生成する安価な方法を提供することを考えると、我々は反応のILの他の種類が行うことができるものを調査に興味を持っていました。この目的のために、我々は、ジアルキルイミダゾリウムを効率的に正式な共役additiでプレ触媒として使用することができることを見出しました1,6-ケトエステルを与えるカルコンに不飽和アルデヒド（ 図1）の上。最も効率的なIL、EMIMAcは、シンナムアルデヒドとカルコンの間で高度に立体選択的反応を促進します。反応は 、抗-ジアステレオマーのために高い優先的に発生し、1,6-ケトエステルは、92％までの収率で単離することができる。24,25,26 <img alt="図1" src="/files/ftp_upload/53213/53213fig1.jpg" /> 図1：三成分、カルコンにシンナムアルデヒドの立体選択的付加を、IL-媒介。

<table>
	<tbody>
		<tr>
			<td>1-ethyl-3-methyl imidazolium acetate</td>
			<td>Aldrich</td>
			<td>51053-100G-F</td>
			<td>Produced by BASF &#8805;90%, dried on a rotary evaporated before use (10 mBar, 40 &#176;C, 1h) 
			CAS NUMBER: 143314-17-4</td>
		</tr>
		<tr>
			<td>1,3-diphenyl-2-propen-1-one</td>
			<td>Aldrich</td>
			<td>11970-100G</td>
			<td>98.0% 
			CAS NUMBER: 94-41-7</td>
		</tr>
		<tr>
			<td>trans-cinnamaldehyde&#160;</td>
			<td>Aldrich</td>
			<td>C80687-25G</td>
			<td>99%, stored under nitrogen prior to use 
			CAS NUMBER: 14371-10-9</td>
		</tr>
		<tr>
			<td>1,8-Diazobicyclo[5.4.0]undec-7-ene</td>
			<td>Aldrich</td>
			<td>139009-25G</td>
			<td>98% 
			CAS NUMBER: 6674-22-2</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Sigma-Aldrich</td>
			<td>32213N-2.5L</td>
			<td>puriss. P.a., ACS reagent, reag. ISO, reag. Ph. Eur. &#8805;99.8% (GC) 
			CAS NUMBER: 67-56-1</td>
		</tr>
		<tr>
			<td>Dichloromethane</td>
			<td>Fischer Chemical</td>
			<td>D/1852/17X</td>
			<td>Analytic reagent grade, stabilized with amylene 
			CAS NUMBER:9/2/1975</td>
		</tr>
		<tr>
			<td>n-Heptane</td>
			<td>Fischer Chemical</td>
			<td>H/0160/17X</td>
			<td>Analytic reagent grade 
			CAS NUMBER: 142-82-5</td>
		</tr>
	</tbody>
</table>

highly stereoselective synthesis of 1,6-ketoesters mediated by ionic liquids: a three-component reaction enabling rapid access to a new class of low molecular weight gelators

In organic chemistry ionic liquids (ILs) have emerged as safe and recyclable reaction solvents. In the presence of a base ILs can be deprotonated to form catalytically active N-Heterocyclic Carbenes (NHCs). Here we have used ILs as precatalysts in the addition of &#945;,&#946;-unsaturated aldehydes to chalcones to form 1,6-ketoesters, incorporating an anti-diphenyl moiety in a highly stereoselective fashion. The reaction has a broad substrate scope and several functional groups and heteroaromatics can be integrated into the ketoester backbone in generally good yields with maintained stereoselectivity. The reaction protocol is robust and scalable. The starting materials are inexpensive and the products can be obtained after simple filtration, avoiding solvent-demanding chromatography. Furthermore, the IL can be recycled up to 5 times without any loss of reactivity. Moreover, the 1,6-ketoester end product is a potent gelator in several hydrocarbon based solvents. The method enables rapid access to and evaluation of a new class of low molecular weight gelators (LMWGs) from recyclable and inexpensive starting materials.

上記例示したように、EMIMAcはカルコンのα、β不飽和アルデヒドの正式な共役付加における触媒前駆体としての役割を果たす。例えば1-エチル-3-メチルイミダゾリウムクロリド（EMIMCl）及び1-ブチル-3-メチルイミダゾリウムクロリド（BMIMCl）などの他の市販のイミダゾリウムベースのイオン液体も調べたが、酢酸アニオンがあってもよいことを示すより低い収率で進行し、これらの...

Watch this Scientific Journal Video about Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular

Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators

Ionic liquids (ILs) mediate fast, simple and cheap access to 1,6-ketoesters in high diastereoselectivities and good yields. The reaction protocol is robust and the 1,6-ketoesters can be obtained in gram scale after a simple filtration protocol. Moreover, the 1,6-ketoesters are potent gelators in hydrocarbon solvents.

イオン液体によって媒介1,6-ケトエステルの高立体選択的合成：低分子ゲル化剤の新しいクラスへの迅速なアクセスを有効にする三成分の反応

In organic chemistry ionic liquids (ILs) have emerged as safe and recyclable reaction solvents. In the presence of a base ILs can be deprotonated to form ...

highly-stereoselective-synthesis-16-ketoesters-mediated-ionic-liquids

Research

JoVE Journal

Chemistry

8.6K ビュー.  Chalmers University of Technology. Ionic liquids (ILs) mediate fast, simple and cheap access to 1,6-ketoesters in high diastereoselectivities and good yields. The reaction protocol is robust and the 1,6-ketoesters can be obtained in gram scale after a simple filtration protocol. Moreover, the 1,6-ketoesters are potent gelators in hydrocarbon solvents. 

ビデオ: Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators

Preparation and Use of Samarium Diiodide (SmI2) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of molecular iodine to samarium metal in THF.1,2-3 It is a mild and selective single electron reductant and its versatility is a result of its ability to initiate a wide range of reductions including C-C bond-forming and cascade or sequential reactions. SmI2 can reduce a variety of functional groups including sulfoxides and sulfones, phosphine oxides, epoxides, alkyl and aryl halides, carbonyls, and conjugated double bonds.2-12 One of the fascinating features of SmI-2-mediated reactions is the ability to manipulate the outcome of reactions through the selective use of cosolvents or additives. In most instances, additives are essential in controlling the rate of reduction and the chemo- or stereoselectivity of reactions.13-14 Additives commonly utilized to fine tune the reactivity of SmI2 can be classified into three major groups: (1) Lewis bases (HMPA, other electron-donor ligands, chelating ethers, etc.), (2) proton sources (alcohols, water etc.), and (3) inorganic additives (Ni(acac)2, FeCl3, etc).3
Understanding the mechanism of SmI2 reactions and the role of the additives enables utilization of the full potential of the reagent in organic synthesis. The Sm-Barbier reaction is chosen to illustrate the synthetic importance and mechanistic role of two common additives: HMPA and Ni(II) in this reaction. The Sm-Barbier reaction is similar to the traditional Grignard reaction with the only difference being that the alkyl halide, carbonyl, and Sm reductant are mixed simultaneously in one pot.1,15 Examples of Sm-mediated Barbier reactions with a range of coupling partners have been reported,1,3,7,10,12 and have been utilized in key steps of the synthesis of large natural products.16,17 Previous studies on the effect of additives on SmI2 reactions have shown that HMPA enhances the reduction potential of SmI2 by coordinating to the samarium metal center, producing a more powerful,13-14,18 sterically encumbered reductant19-21 and in some cases playing an integral role in post electron-transfer steps facilitating subsequent bond-forming events.22 In the Sm-Barbier reaction, HMPA has been shown to additionally activate the alkyl halide by forming a complex in a pre-equilibrium step.23
Ni(II) salts are a catalytic additive used frequently in Sm-mediated transformations.24-27 Though critical for success, the mechanistic role of Ni(II) was not known in these reactions. Recently it has been shown that SmI2 reduces Ni(II) to Ni(0), and the reaction is then carried out through organometallic Ni(0) chemistry.28
These mechanistic studies highlight that although the same Barbier product is obtained, the use of different additives in the SmI2 reaction drastically alters the mechanistic pathway of the reaction. The protocol for running these SmI2-initiated reactions is described.

Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction

A straightforward procedure for the preparation of samarium diiodide (SmI2) in THF is described. The role of two main additives namely hexamethylphosphoramide (HMPA) and Ni(acac)2 in Sm mediated reactions is demonstrated in the Sm-Barbier reaction.

二ヨウ化サマリウム（SMIの調製および使用<sub&gt; 2</sub&gt;）有機合成における：サマリウムバルビエ反応におけるHMPAとNi（II）塩の力学的役割

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of ...

化学

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150&#160;nm. The nMST material was found to have a Brunauer-Emmett-Teller (BET) surface area of 285 m2g-1, which is more than an order of magnitude higher than the micron-sized MST. The isoelectric point of the nMST measured 3.34 pH units, which is a pH unit lower than that measured for the micron-size MST. The nMST material was found to serve as an effective ion exchanger under weakly acidic conditions for the preparation of an Au(III)-exchange nanotitanate. In addition, the formation of the corresponding peroxotitanate was demonstrated by reaction of the nMST with hydrogen peroxide.

The surfactant mediated sol-gel synthesis of nanosized monosodium titanate is described, along with preparation of the corresponding peroxide modified material. An ion-exchange reaction with Au(III) is also presented.

ナノサイズ一ナトリウムチタン酸の合成と反応化学

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the ...

Synthesis and Exfoliation of Discotic Zirconium Phosphates to Obtain Colloidal Liquid Crystals

Due to their abundance in natural clay and potential applications in advanced materials, discotic nanoparticles are of interest to scientists and engineers. Growth of such anisotropic nanocrystals through a simple chemical method is a challenging task. In this study, we fabricate discotic nanodisks of zirconium phosphate [Zr(HPO4)2&#183;H2O] as a model material using hydrothermal, reflux and microwave-assisted methods. Growth of crystals is controlled by duration time, temperature, and concentration of reacting species. The novelty of the adopted methods is that discotic crystals of size ranging from hundred nanometers to few micrometers can be obtained while keeping the polydispersity well within control. The layered discotic crystals are converted to monolayers by exfoliation with tetra-(n)-butyl ammonium hydroxide [(C4H9)4NOH, TBAOH]. Exfoliated disks show isotropic and nematic liquid crystal phases. Size and polydispersity of disk suspensions is highly important in deciding their phase behavior.

A two dimensional model material of discotic zirconium phosphate was developed. The inorganic crystal with lamellar structure was synthesized by hydrothermal, reflux, and microwave-assisted methods. On exfoliation with organic molecules, layered crystals can be converted to monolayers, and nematic liquid crystal phase was formed at sufficient concentration of monolayers.

コロイド液の結晶を得ることが合成とディスコティックリン酸ジルコニウムの剥離

Due to their abundance in natural clay and potential applications in advanced materials, discotic nanoparticles are of interest to scientists and ...

Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction

This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline elastomers (LCEs) with facile control over network structure and programming of an aligned monodomain. Tailored LCE networks were synthesized using routine mixing of commercially available starting materials and pouring monomer solutions into molds to cure. An initial polydomain LCE network is formed via a self-limiting thiol-acrylate Michael-addition reaction. Strain-to-failure and glass transition behavior were investigated as a function of crosslinking monomer, pentaerythritol tetrakis(3-mercaptopropionate) (PETMP). An example non-stoichiometric system of 15 mol% PETMP thiol groups and an excess of 15 mol% acrylate groups was used to demonstrate the robust nature of the material. The LCE formed an aligned and transparent monodomain when stretched, with a maximum failure strain over 600%. Stretched LCE samples were able to demonstrate both stress-driven thermal actuation when held under a constant bias stress or the shape-memory effect when stretched and unloaded. A permanently programmed monodomain was achieved via a second-stage photopolymerization reaction of the excess acrylate groups when the sample was in the stretched state. LCE samples were photo-cured and programmed at 100%, 200%, 300%, and 400% strain, with all samples demonstrating over 90% shape fixity when unloaded. The magnitude of total stress-free actuation increased from 35% to 115% with increased programming strain. Overall, the two-stage TAMAP methodology is presented as a powerful tool to prepare main-chain LCE systems and explore structure-property-performance relationships in these fascinating stimuli-sensitive materials.

A novel methodology is presented to synthesize and program main-chain liquid-crystalline elastomers using commercially available starting monomers. A wide range of thermomechanical properties was tailored by adjusting the amount of crosslinker, while the actuation performance was dependent on the amount of applied strain during programming.

二段チオールアクリレート反応を使用してプログラム可能な、主鎖液晶エラストマーの合成

This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline ...

Synthesis of Cd-free InP/ZnS Quantum Dots Suitable for Biomedical Applications

Fluorescent nanocrystals, specifically quantum dots, have been a useful tool for many biomedical applications. For successful use in biological systems, quantum dots should be highly fluorescent and small/monodisperse in size. While commonly used cadmium-based quantum dots possess these qualities, they are potentially toxic due to the possible release of Cd2+ ions through nanoparticle degradation. Indium-based quantum dots, specifically InP/ZnS, have recently been explored as a viable alternative to cadmium-based quantum dots due to their relatively similar fluorescence characteristics and size. The synthesis presented here uses standard hot-injection techniques for effective nanoparticle growth; however, nanoparticle properties such as size, emission wavelength, and emission intensity can drastically change due to small changes in the reaction conditions. Therefore, reaction conditions such temperature, reaction duration, and precursor concentration should be maintained precisely to yield reproducible products. Because quantum dots are not inherently soluble in aqueous solutions, they must also undergo surface modification to impart solubility in water. In this protocol, an amphiphilic polymer is used to interact with both hydrophobic ligands on the quantum dot surface and bulk solvent water molecules. Here, a detailed protocol is provided for the synthesis of highly fluorescent InP/ZnS quantum dots that are suitable for use in biomedical applications.

In this protocol, the synthesis of Cd-free InP/ZnS quantum dots (QDs) is detailed. InP-based QDs are gaining popularity due to the toxicity of Cd2+ ions that may be released through nanoparticle degradation. After synthesis, QDs are solubilized in water using an amphiphilic polymer for use in biomedical applications.

バイオメディカル応用のための適切なカドミウムフリーのInP / ZnSの量子ドットの合成

Fluorescent nanocrystals, specifically quantum dots, have been a useful tool for many biomedical applications. For successful use in biological systems, ...

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.

Photoredox触媒を用いた可視光媒介分散重合によるワームのようなミセルの簡便な合成

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

Controlled Synthesis and Fluorescence Tracking of Highly Uniform Poly(N-isopropylacrylamide) Microgels

Stimuli-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have various prospective practical applications and uses in fundamental research. In this work, we use single particle tracking of fluorescently labeled PNIPAM microgels as a showcase for tuning microgel size by a rapid non-stirred precipitation polymerization procedure. This approach is well suited for prototyping new reaction compositions and conditions or for applications that do not require large amounts of product. Microgel synthesis, particle size and structure determination by dynamic and static light scattering are detailed in the protocol. It is shown that the addition of functional comonomers can have a large influence on the particle nucleation and structure. Single particle tracking by wide-field fluorescence microscopy allows for an investigation of the diffusion of labeled tracer microgels in a concentrated matrix of non-labeled microgels, a system not easily investigated by other methods such as dynamic light scattering.

Controlled Synthesis and Fluorescence Tracking of Highly Uniform PolyN-isopropylacrylamide Microgels

Non-stirred precipitation polymerization provides a rapid, reproducible prototyping approach to the synthesis of stimuli-sensitive poly(N-isopropylacrylamide) microgels of narrow size distribution. In this protocol synthesis, light scattering characterization and single particle fluorescence tracking of these microgels in a wide-field microscopy setup are demonstrated.

制御された合成および均一性の高いポリの蛍光トラッキング（<em&gt; N</em&gt; -isopropylacrylamide）ミクロゲル

Stimuli-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have various prospective practical applications and uses in fundamental research. In this ...

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

Herein, we demonstrate that a bottom-up approach, based on halogen bonding (XB), can be successfully applied for the design of a new type of ionic liquid crystals (ILCs). Taking advantages of the high specificity of XB for haloperfluorocarbons and the ability of anions to act as XB-acceptors, we obtained supramolecular complexes based on 1-alkyl-3-methylimidazolium iodides and iodoperfluorocarbons, overcoming the well-known immiscibility between hydrocarbons (HCs) and perfluorocarbons (PFCs). The high directionality of the XB combined with the fluorophobic effect, allowed us to obtain enantiotropic liquid crystals where a rigid, non-aromatic, XB supramolecular anion acts as mesogenic core.
X-ray structure analysis of the complex between 1-ethyl-3-methylimidazolium iodide and iodoperfluorooctane showed the presence of a layered structure, which is a manifestation of the well-known tendency to segregation of perfluoroalkyl chains. This is consistent with the observation of smectic mesophases. Moreover, all the reported complexes melt below 100 &#176;C, and most are mesomorphic even at room temperature, despite that the starting materials were non-mesomorphic in nature.
The supramolecular strategy reported here provides new design principles for mesogen design allowing a totally new class of functional materials.

A protocol for the synthesis of a new type of mesogens, based on the halogen-bonded supramolecular anion [CnF2n+1-I&#183;&#183;&#183;I&#183;&#183;&#183;I-CnF2n+1]&#8722;, is reported.

分子から素材まで: ハロゲン結合を介して新しいイオン液体結晶工学

Herein, we demonstrate that a bottom-up approach, based on halogen bonding (XB), can be successfully applied for the design of a new type of ionic liquid ...

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity and convenient colorimetric readout. However, high densities of nanoparticles are typically needed for detection. The available synthesis-based enhancement protocols are either limited to gold and silver nanoparticles or rely on precise enzymatic control and optimization. Here, we present a protocol to enhance the colorimetric readout of gold, silver, silica, and iron oxide nanoprobes. It was observed that the colorimetric signal can be improved by up to a 10000-fold factor. The basis for such signal enhancement strategies is the chemical reduction of Au3+ to Au0. There are several chemical reactions that enable the reduction of Au3+ to Au0. In the protocol, Good&#39;s buffers and H2O2 are used and it is possible to favor the deposition of Au0 onto the surface of existing nanoprobes, in detriment of the formation of new gold nanoparticles. The protocol consists of the incubation of the microarray with a solution consisting of chloroauric acid and H2O2 in 2-(N-morpholino)ethanesulfonic acid pH 6 buffer following the nanoprobe-based detection assay. The enhancement solution can be applied to paper and glass-based sensors. Moreover, it can be used in commercially available immunoassays as demonstrated by the application of the method to a commercial allergen microarray. The signal development requires less than 5 min of incubation with the enhancement solution and the readout can be assessed by naked eye or low-end image acquisition devices such as a table-top scanner or a digital camera.

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

In this work, a protocol for signal enhancement of nanoprobe-based biosensing is presented. The protocol is based on the reduction of chloroauric acid onto the surface of existing nanoprobes that consist of gold, silver, silica or iron-oxide nanoparticles.

原金ナノ粒子合成による急速なナノプローブ信号強調

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity ...

Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain

Barium titanate (BaTiO3, hereafter BT) is an established ferroelectric material first discovered in the 1940s and still widely used because of its well-balanced ferroelectricity, piezoelectricity, and dielectric constant. In addition, BT does not contain any toxic elements. Therefore, it is considered to be an eco-friendly material, which has attracted considerable interest as a replacement for lead zirconate titanate (PZT). However, bulk BT loses its ferroelectricity at approximately 130 &#176;C, thus, it cannot be used at high temperatures. Because of the growing demand for high-temperature ferroelectric materials, it is important to enhance the thermal stability of ferroelectricity in BT. In previous studies, strain originating from the lattice mismatch at hetero-interfaces has been used. However, the sample preparation in this approach requires complicated and expensive physical processes, which are undesirable for practical applications.
In this study, we propose a chemical synthesis of a porous material as an alternative means of introducing strain. We synthesized a porous BT thin film using a surfactant-assisted sol-gel method, in which self-assembled amphipathic surfactant micelles were used as an organic template. Through a series of studies, we clarified that the introduction of pores had a similar effect on distorting the BT crystal lattice, to that of a hetero-interface, leading to the enhancement and stabilization of ferroelectricity. Owing to its simplicity and cost effectiveness, this fabrication process has considerable advantages over conventional methods.

Here, we present a protocol for the synthesis of porous barium titanate (BaTiO3) thin film by a surfactant-assisted sol-gel method, in which self-assembled amphipathic surfactant micelles are used as an organic template.