Cluster Catalysts of Zinc and Cobalt for Transesterification and Amide Alcoholysis

Seminar series
Inorganic Chemistry
Wed, May 21 4:30pm
Cram Conference Room, 3440 Mol Sci
Speaker Professor Kazushi Mashima
Osaka University
Graduate School of Engineering Science

The ester moiety represents one of the most ubiquitous functional groups in organic compounds, serving as both key intermediate and protecting group in organic transformations. Among various esterification reactions established so far, one of the most convenient synthetic methods is transesterification, in which methyl or ethyl esters react with various alcohols to give the corresponding esters in one step.  We developed m-oxo-tetranuclear zinc cluster Zn4(OCOCF3)6O as an efficiently catalyst for transesterification, including chemoselective acylation of hydroxy group in the presence of aliphatic amino group, catalytic acetylation of alcohols and catalytic deacetylation of acetates. Because of mildness of the reaction conditions, these reactions have a high degree of functional-group tolerance. Recently, cobalt clusters mediate the same chemoselectivity for transesterification.  Amide bond formation and degradation are also discussed.