General Metal-Free Baeyer–Villiger-Type Synthesis of Vinyl Acetates
摘要:
Ozone, a cheap, stable, and nonhazardous oxidizing reagent, transforms alpha,beta-unsaturated ketones of defined stereochemistry into their corresponding vinyl acetates through a Baeyer-Villiger reaction. This process is general and straightforward, tolerating a wide range of functional groups.
Supported Ionic Liquids. New Recyclable Materials for theL-Proline-Catalyzed Aldol Reaction
作者:Michelangelo Gruttadauria、Serena Riela、Carmela Aprile、Paolo Lo Meo、Francesca D'Anna、Renato Noto
DOI:10.1002/adsc.200505227
日期:2006.1
Newmaterials for L-proline recycling have been developed. These materials have been applied to the L-proline-catalyzed aldolreaction between acetone and several aldehydes. The L-proline has been supported on the surface of modified silica gels with a monolayer of covalently attached ionicliquid with or without additional adsorbed ionicliquid. Good yields and ee values, comparable with those obtained
Direct Organocatalytic Asymmetric Heterodomino Reactions: The Knoevenagel/Diels−Alder/Epimerization Sequence for the Highly Diastereoselective Synthesis of Symmetrical and Nonsymmetrical Synthons of Benzoannelated Centropolyquinanes
作者:D. B. Ramachary、K. Anebouselvy、Naidu S. Chowdari、Carlos F. Barbas
DOI:10.1021/jo049581r
日期:2004.9.1
Aminoacids and amines have been used to catalyze three component hetero-domino Knoevenagel/Diels−Alder/epimerization reactions of readily available various precursor enones (1a−l), aldehydes (2a−p), and 1,3-indandione (3). The reaction provided excellent yields of highly substituted, symmetrical and nonsymmetrical spiro[cyclohexane-1,2‘-indan]-1‘,3‘,4-triones (5) in a highly diastereoselective fashion
Optically pure (R) allylic alcohols and (R) 4-phenylbutan-2-ols were prepared via oxidative kinetic resolution using whole cells of Candida papapsilosis ATCC 7330.
Palladium-catalyzed Mizoroki–Heck reactions were carried out in the presence of calcium carbonate in alcoholic solvents. Under these conditions an efficient preparation of functionalized benzalacetones was developed. The reactions were carried out at room temperature and aerobic conditions, giving the products within several minutes in up to 95% isolated yields. Furthermore, some kinetic investigations
of α,β-unsaturated methyl ketone/nitro compounds from benzylic amines through an oxidation–aldol/Henry reaction is reported. The reaction proceeded well by using MCPBA as oxidant and CuCl2·2H2O as catalyst. A variety of functionalized α,β-unsaturated methyl ketone/nitro compounds were assembled in moderate yields by application of this catalytic one-pot reaction.