The compatibility of the generation of furylhydroperoxides by a radical chain process with the presence of oxygen acceptors and transition metal catalysts allows the achievement of a modified Sharpless procedure for the epoxidation of allylic alcohols and oxidation of sulphides to sulphoxides.
Carbonylation of Epoxides to Substituted 3-Hydroxy-δ-Lactones
作者:John W. Kramer、Daniel Y. Joh、Geoffrey W. Coates
DOI:10.1021/ol702475e
日期:2007.12.1
Substituted 3-hydroxy-delta-lactones (3HLs) are valuable intermediates in the synthesis of pharmaceuticals and other biologically active-natural products. Herein we report the first example of the catalytic carbonylation of substituted homoglycidols to 3HLs using HCo(CO)(4). Upon optimization of the catalyst and reaction conditions, a functionally diverse set of 3HLs was prepared. Mechanistic insight was gained by observation of the carbonylation reaction using in situ IR spectroscopy, and we propose a mechanism that is consistent with previously studied epoxide carbonylation systems.
Vanadium‐Catalyzed Enantioselective Desymmetrization of
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Secondary Allylic Alcohols and Homoallylic Alcohols
作者:Zhi Li、Wei Zhang、Hisashi Yamamoto
DOI:10.1002/anie.200802523
日期:2008.9.15
Vanadium-catalyzed epoxidation has extended substrate scope. In addition to various bis-allylic alcohols, bis-homoallylic alcohols can also be desymmetrized using our Vanadium-Bis-hydroxamic acid complexes.