Synthesis of Unsymmetrically Substituted 1,3-Butadiynes and 1,3,5-Hexatriynes via Alkylidene Carbenoid Rearrangements
作者:Annabelle L. K. Shi Shun、Erin T. Chernick、Sara Eisler、Rik R. Tykwinski
DOI:10.1021/jo026481h
日期:2003.2.1
Unsymmetrically substituted 1,3-butadiynes and 1,3,5-hexatriynes are synthesized in four steps from commercially available aldehydes or carboxylic acids. The key step in this process involves a Fritsch-Buttenberg-Wiechell rearrangement, in which an alkylidene carbenoid intermediate subsequently rearranges to the desired polyyne. This rearrangement proceeds under mild conditions, and it is tolerant
A fine addition! A highlyenantioselective and efficient procedure for the amino‐alcohol–zinc‐catalyzedaddition of trimethylsilylacetylene to aromatic, α,β‐unsaturated, and aliphatic aldehydes has been developed (see scheme; R=aryl, alkynyl, or alkyl; TMS=trimethylsilyl; TBDMS=tert‐butyldimethylsilyl). The present protocol was successfully applied in the concise synthesis of the natural products marine
很好的补充!已开发出一种高度对映选择性和高效的程序,用于氨基醇锌催化的三甲基甲硅烷基乙炔加成到芳族,α,β-不饱和和脂肪族醛中(见方案; R =芳基,炔基或烷基; TMS =三甲基甲硅烷基; TBDMS =叔丁基二甲基甲硅烷基)。本协议已成功地应用于天然产物海洋炔醇和法卡林二醇的简明合成中。
Ionic-Surfactant-Coated Burkholderia cepacia Lipase as a Highly Active and Enantioselective Catalyst for the Dynamic Kinetic Resolution of Secondary Alcohols
作者:Hyunjin Kim、Yoon Kyung Choi、Jusuk Lee、Eungyeong Lee、Jaiwook Park、Mahn-Joo Kim
DOI:10.1002/anie.201104141
日期:2011.11.11
With a coat for activity: A highly active enzyme was prepared by coating Burkholderia cepacia lipase with an ionic surfactant for use in dynamic kineticresolution (DKR). Important features of this enzyme include: the fastest DKR of 1‐phenylethanol, the highlyenantioselective DKR of a wide range of secondary alcohols (RCH(OH)Ar), and the switching of lipase enantioselectivity in DKR depending on the shape
Modification of the Fritsch–Buttenberg–Wiechell rearrangement: a facile route to unsymmetrical butadiynes
作者:Erin T Chernick、Sara Eisler、Rik R Tykwinski
DOI:10.1016/s0040-4039(01)01901-3
日期:2001.12
echell rearrangement has been used to form unsymmetrically substituted 1,3-butadiynes from 1,1-dibromo-olefin precursors. The reaction proceeds via lithium–halogen exchange, followed by migration of the aryl or alkynyl moiety to provide the butadiyne framework. The facile formation of the dibromo-olefins in three steps from commercially available aryl aldehydes or carboxylic acid chlorides makes this
Design and Synthesis of Co‐initiators via Base‐Catalysed Sequential Conjugate Addition: Application in Photoinduced Radical Polymerisation Reaction
作者:Asrar Ahmad、Shakir Ali Siddiqui、Garvisha Mittal、N. Sukumar、Kshatresh Dutta Dubey、Ajoy Kapat
DOI:10.1002/chem.202301844
日期:2023.10.13
A highly efficient synthesis of a co-initiator for a type-II photoinitiator promoted photoinduced radical polymerzation reaction via a barrierless catalyticsequentialconjugate addition reaction. The computational study confirms the presence of a low HOMO-LUMO gap for the newly developed addition reaction. The 1,2-benzenedithiol-based co-initiator turned out to be very efficient for the polymerization
II型光引发剂共引发剂的高效合成通过无势垒催化顺序共轭加成反应促进了光诱导自由基聚合反应。计算研究证实了新开发的加成反应存在较低的 HOMO-LUMO 间隙。事实证明,基于 1,2-苯二硫醇的共引发剂对于聚合反应非常有效,并且所得聚合物材料对于牙齿修复和 3D 打印具有优异的物理性能。