Asymmetric Aza-Wittig Reactions: Enantioselective Synthesis of β-Quaternary Azacycles

摘要

Polysubstituted nitrogen heterocycles are prevalent in pharmaceuticals and biologically important natural product targets, and new approaches to these systems are in constantdemand. A frequently occurring motif is the presence of anasymmetric all-carbon quaternary center in the 3-position ofpyrrolidines, piperidines, and their polycyclic derivatives. Allcarbon quaternary stereocenters are amongst the most challenging constructs in modern synthesis,[1] and a new approach to such functionality would be of considerableutility.