Synthesis of γ-amino esters via Mn-mediated radical addition to chiral γ-hydrazonoesters

Abstract

Highly stereoselective Mn-mediated couplings of alkyl iodides with chiral N-acylhydrazones bearing ester functionality afford a series of gamma;-hydrazino esters, including gamma;-substituted, α,gamma;-disubstituted, and α,α,gamma;-trisubstituted examples. In contrast to prior work with chiral N-acylhydrazones, high stereoselectivity was observed even in the absence of Lewis acid. Microwave-assisted acylation with trifluoroacetic anhydride and reductive N-N bond cleavage provided the γ-amino ester functionality in a synthetically useful N-TFA-protected form. © 2009 American Chemical Society.