The indium(III) chloride-catalysed hydrolysis and in situ Mukaiyama-type reaction of arylmethyl ketone derived silyl enol ethers under solvent-free conditions
摘要:
Treatment of trimethylsilyl enol ethers of arylmethyl ketones with catalytic amounts of indium(111) chloride under solvent-free conditions leads to a remarkably efficient process of in situ hydrolysis and Mukaiyama-type addition to the resulting ketones. (C) 2003 Elsevier Ltd. All rights reserved.
Homogeneous catalysis. transition metal based lewis acid catalysts.
作者:T. Keith Hollis、William Odenkirk、N.P. Robinson、John Whelan、B. Bosnich
DOI:10.1016/s0040-4020(01)87259-8
日期:1993.1
Transition metal basedLewisacids provide catalysts for the Diels-Alder and Mukaiyama reactions. These catalysts must possess an electron deficient axophilic metal center and a labile coordination position. Unlike traditional Lewisacids, those derived from transition metals can function in the presence of water and have welldefined structures. It is shown how a normally electron rich ruthenium atom
In the presence of a mesoporous aluminosilicate Al-MCM-41, aldolreaction of various silyl enol ethers with both aromatic and aliphatic aldehydes proceeded under mild reaction conditions to afford the corresponding O-silylated aldol adducts in high yields. The solid acid catalyst was easily recovered and reusable three times.
Electrogenerated Acid-Catalyzed Reactions of Acetals, Aldehydes, and Ketones with Organosilicon Compounds, Leading to Aldol Reactions, Allylations, Cyanations, and Hydride Additions
electrogenerated acid (EG acid) in the silicon-mediated acid-catalyzed reactions; e.g., aldol reactions, allylations, cyanations, and hydride additions is described. The aldol reaction of acetals 1 with enol trimethylsilyl ethers 3 and 1,2-bis(trimethylsiloxy)alkenes 4 gives the corresponding adducts 5 and 6, respectively. The reaction proceeds smoothly with EG acid derived from perchlorate salts such
Unprecedented alkylation of silicon enolates with alcohols via carbenium ion formations catalyzed by tin hydroxide-embedded montmorillonite
作者:Michael Andreas Tandiary、Masashi Asano、Taiki Hattori、Satoshi Takehira、Yoichi Masui、Makoto Onaka
DOI:10.1016/j.tetlet.2017.03.073
日期:2017.5
The solid acid, tin hydroxide-embedded montmorillonite, catalyzes the unprecedentedalkylation of various silicon enolates with primary, secondary and tertiary benzylic alcohols as well as secondary allylic alcohols. The acid catalysis of Sn-Mont was not only higher than that of the other ion-exchanged montmorillonites (M-Mont; M = H, Ti, Fe and Al), but also higher than that of the typical homogeneous
固体酸,氢氧化锡包埋的蒙脱石可催化各种烯醇硅与伯,仲和叔苄醇以及仲烯丙基醇的空前烷基化。Sn-Mont的酸催化作用不仅高于其他离子交换的蒙脱土(M-Mont; M = H,Ti,Fe和Al),而且高于典型的均相酸催化剂(如BF)3 ·OEt 2,TMSOTf和TfOH。
Cationic iridium complex is a new and efficient Lewis acid catalyst for aldol and Mannich reactions
A cationic iridium complex [Ir(cod)2]SbF6 was found to be a new and efficient Lewis acid catalyst for Mukaiyama aldol and Mannich reactions. Aldehydes react smoothly with silyl enol ethers to give β-siloxy ketones in the presence of 0.5 mol % of [Ir(cod)2]SbF6. The reaction of N-alkyl arylaldimines with ketene silyl acetals in the presence of 5 mol % [Ir(cod)2]SbF6/P(OPh)3 gave β-amino esters. After