Asymmetric Synthesis of a Quaternary Carbon Stereogenic Center by Organocatalysis Using a Primary Amino Acid and Its Salt

In this personal account, our recent developments on the asymmetric synthesis of a quaternary carbon stereogenic center by organocatalysis using a primary amino acid and its salt as a catalyst are described in three chapters: (1) conjugate addition to nitroalkenes and vinyl ketones, (2) nucleophilic addition to pi-allyl palladium complexes, and (3) nucleophilic substitution reactions with allyl and propargyl halides. By these methods, asymmetric alpha-allylation of alpha-branched aldehydes and ketones smoothly proceeded to give gamma-nitroaldehydes, ketoaldehydes, alpha-allylated aldehydes, and alpha-allylated beta-ketoesters possessing a quaternary carbon stereogenic center in good yields with high enantioselectivities.

Automated summary

This article describes recent developments in asymmetric synthesis of a quaternary carbon stereogenic center using organocatalysis with a primary amino acid and its salt as a catalyst. The three chapters cover conjugate addition to nitroalkenes and vinyl ketones, nucleophilic addition to pi-allyl palladium complexes, and nucleophilic substitution reactions with allyl and propargyl halides. These methods have successfully achieved asymmetric alpha-allylation of alpha-branched aldehydes and ketones, giving gamma-nitroaldehydes, ketoaldehydes, alpha-allylated aldehydes, and alpha-allylated beta-ketoesters with a quaternary carbon stereogenic center in good yields and high enantioselectivities.