Catalytic Asymmetric Intramolecular Homologation of Ketones with alpha-Diazoesters: Synthesis of Cyclic alpha-Aryl/Alkyl beta-Ketoesters

摘要

A catalytic asymmetric intramolecular homologation of simple ketones with alpha-diazoesters was firstly accomplished with a chiral N,N'-dioxide-Sc(OTf)(3) complex. This method provides an efficient access to chiral cyclic alpha-aryl/alkyl beta-ketoesters containing an all-carbon quaternary stereocenter. Under mild conditions, a variety of aryl-and alkyl-substituted ketone groups reacted with alpha-diazoester groups smoothly through an intramolecular addition/rearrangement process, producing the beta-ketoesters in high yield and enantiomeric excess.