有用シクロプロパンカルボン酸類の接触的不整合成 カルベン‐銅錯体の不整合成への応用

Abstract

Reaction of alkyl diazoacetate with an olefin catalyzed by a chiral copper complex gives an optically active alkyl cyclopropanecarboxylate. This chiral copper carbenoid reaction was successfully applied to the synthesis of industrially valuable cyclopropanecarboxylic acids : (+) -trans-chrysanthemic acid, (+) -cis-permethrinic acid and (+) -2, 2-dimethylcyclopropanecarboxylic acid. A series of effective catalysts, chiral Schiff base-copper complexes, was prepared starting with an optically active α-amino acid to achieve more than 90 % e.e. of the products. The chirality of the products was correlated with that of the catalyst on the basis of metallacyclobutane intermediates.