Asymmetric synthesis of a to nitrogen substituted azaheterocycles. Application to the total synthesis of S-(-)-Anabasine.

Chiral azaheterocycles substituted a to nitrogen represent the core unit of a wide range of alkaloids and biologically active compounds. They also play an important role as key targets for the pharmaceutical industry. Consequently, the stereocontrol of carbon centers embedded in these azaheterocycles is a permanent synthetic task for organic chemists. In this regard, we have developed an alternative and conceptually new synthetic approach to a variety of 2-heteroaryl cyclic amines and 6-aryl piperidin-2-ones which is based upon the asymmetric reduction of chiral endocyclic enenydrazides bearing a (S)-methylprolinol chiral auxiliary (SMP). This new synthetic methodology has then been illustrated by the total synthesis of S-(‑)-Anabasine and the stereoselective synthesis of cis-2,6-diarylated piperidines in high yields and high level of enantioselectivity.