Lithium Bromide, a Novel and Highly Effective Catalyst for Monothioacetalization of Acetals under Mild Reaction Conditions
作者:Fumiaki Ono、Ryojyu Negoro、Tsuneo Sato
DOI:10.1055/s-2001-17477
日期:——
Lithium bromide is efficient as a catalyst for the monothioacetalization of acetals under mild reaction conditions to provide products in excellent yields with high chemoselectivity.
Monothioacetals are obtained by treating the corresponding acetals with organotin thiophenoxides in the presence of BF2·OEt2. The reaction proceeds under mild conditions to provide the desired compounds with high selectivity.
Catalyst-Dependent Selective Synthesis of O/S- and S/S-Acetals from Enol Ethers
作者:Antonio L. Braga、Claudio C. Silveira、Luciano Dornelles、Gilson Zeni、Flavia A. D. Galarza、Ludger A. Wessjohann
DOI:10.1080/00397919508015466
日期:1995.10
Abstract Enol ethers are reacted with mercaptanes to give the corresponding O/S- or S/S-acetals in medium to high yield. Either product can be formed selectively depending on the acid catalyst and the reaction time applied.
Dicyanoketene acetals, a novel type of π-acid catalyst for monothioacetalization of acetals
作者:Tsuyoshi Miura、Yukio Masaki
DOI:10.1016/0040-4039(94)80022-7
日期:1994.10
Dicyanoketeneacetals such as dicyanoketene dimethyl acetal and ethylene are introduced to be a noveltype of π-acidcatalyst for the monothioacetalization of acetals. Particularly, the catalytic activity of dicyanoketene ethylene acetal was found to be superior to that of tetracyanoethylene and chemoselective in the crossover of the monothioacetalization of a ketone-, an aldehyde-acetal and an alcohol
Monothioacetalization of acetals catalyzed by dicyanoketene acetals
作者:Tsuyoshi Miura、Yukio Masaki
DOI:10.1016/0040-4020(95)00627-k
日期:1995.9
A type of capto-dative olefin, dicyanoketeneacetal such as dicyanoketene dimethyl acetal and ethylene acetal is introduced to be a noveltype of π-acidcatalyst for the monothioacetalization of acetals as well as the corresponding α,β-unsaturated systems. Particularly, the catalytic activity of dicyanoketene ethylene acetal was found to be superior to that of tetracyanoethylene and highly chemoselective