InCl<sub>3</sub>/Me<sub>3</sub>SiBr-Catalyzed Direct Coupling between Silyl Ethers and Enol Acetates
作者:Yoshiharu Onishi、Yoshihiro Nishimoto、Makoto Yasuda、Akio Baba
DOI:10.1021/ol200875m
日期:2011.5.20
A combined Lewis acid catalyst of InCl3 and Me3SiBr promoted the direct use of enol acetates in the coupling with low-reactive silyl ethers, in which functional groups including ketones and aldehydes survived. Sterically hindered silyl ethers such as ROSiEt3, ROSiPh3, ROSit-BuMe2, and ROSii-Pr3 were also applicable.
Indium-catalyzed coupling reaction between silyl enolates and alkyl chlorides or alkyl ethers
作者:Yoshihiro Nishimoto、Takahiro Saito、Makoto Yasuda、Akio Baba
DOI:10.1016/j.tet.2009.03.106
日期:2009.7
The coupling reactions of alkyl chlorides with silyl enolates catalyzed by InBr3, and the coupling reactions of alkylethers with silyl enolates catalyzed by the combined Lewis acid of InBr3/Me3SiBr are described. In both reaction systems, various types of silyl enolates were used to give corresponding α-alkylated esters, ketones, carboxylic acids, amides, thioesters, and aldehydes.
描述了烷基氯化物与InBr 3催化的烯醇硅酸酯的偶联反应,以及烷基醚与InBr 3 / Me 3 SiBr的路易斯酸催化的烯醇硅酸酯的偶联反应。在两个反应系统中,都使用了各种类型的甲硅烷基烯酸酯,以生成相应的α-烷基化的酯,酮,羧酸,酰胺,硫代酯和醛。
α-Alkylation of Ketones by Addition of Zinc Enamides to Unactivated Olefins
A zinc enamide generated from the corresponding N-aryl imine undergoes addition to an unactivatedolefin, such as ethylene, 1-octene, and isobutylene, to generate an alpha-alkylated gamma-zincioimine intermediate in good to excellent yield. Terminal and gem-disubstituted olefins react with >99% regioselectivity, allowing the C-C bond formation to take place at the more hindered carbon of the double
由相应的 N-芳基亚胺生成的锌烯酰胺与未活化的烯烃(例如乙烯、1-辛烯和异丁烯)加成,以良好至极好的收率生成 α-烷基化 γ-锌亚胺中间体。末端和偕二取代的烯烃以>99% 的区域选择性反应,使得 CC 键的形成发生在双键的受阻更大的碳上。有机锌中间体与碳亲电子试剂进一步形成 CC 键,在亚胺水解后,生成带有各种官能化伯、仲和叔烷基的 α-烷基化酮。
α-Alkylation of Carbonyl Compounds by Direct Addition of Alcohols to Enol Acetates
作者:Yoshihiro Nishimoto、Yoshiharu Onishi、Makoto Yasuda、Akio Baba
DOI:10.1002/anie.200904069
日期:2009.11.16
A practical α‐alkylation of ketones and aldehydes has been achieved by the directaddition of alcohols to enolacetates. The moderate Lewis acidity of InI3, GaBr3, and FeBr3 is a key factor in the catalytic cycle, and many different alcohols and enolacetates have been successfully used in this procedure.
Lewis and mediated α-alkylation of ketones using SN1 reactive alkylating agents
作者:M.T. Reetz、S. Hüttenhain、P. Walz、U. Löwe
DOI:10.1016/s0040-4039(01)86764-2
日期:——
Alkylation of ketones via silyl enol ethers is possible using aryl activated secondary alkyl halides or thio ketals. In case of prenyl halides the ratio fo primary to tertiary alkylation is governed by steric factors and by the nature of the Lewis acid.