An Efficient Catalytic Asymmetric Epoxidation Method
作者:Zhi-Xian Wang、Yong Tu、Michael Frohn、Jian-Rong Zhang、Yian Shi
DOI:10.1021/ja972272g
日期:1997.11.1
This article describes a highly effective catalyticasymmetricepoxidation method for olefins using potassium peroxomonosulfate (Oxone, Dupont) as oxidant and a fructose-derived ketone (1) as catalyst. High enantioselectivies have been obtained for trans-disubstituted and trisubstituted olefins which can bear functional groups such as tributylsilyl ether, acetal, chloride, and ester. The enantiomeric
1,3-Disubstituted tetrabutyldistannoxanes catalyze acetilization of carbonyl compounds undermildconditions. Thorough investigations of factors influencing this reaction are given. A variety of synthetically useful carbonyl compounds are efficiently converted to acetals. In particular, acetilization of cyclic α,β-unsaturated ketones is readily achieved which have met with only limited success so far
Selective Transdithioacetalization of Acetals, Ketals, Oxathioacetals and Oxathioketals Catalyzed by Envirocat EPZ10R
作者:A. S. Gajare、M. S. Shingare、B. P. Bandgar
DOI:10.1039/a800864g
日期:——
Envirocat EPZ10R has been found to be a remarkable reusable heterogeneous catalyst for selective transdithioacetalization of acetals, ketals, oxathioacetals and oxathioketals with HSCH2CH2SH and HSCH2CH2CH2SH.