Step-economical access to valuable Weinreb amide 2,5-disubstituted pyrrolidines by a sequential one-pot two-directional cross-metathesis/cyclizing aza-Michael process

摘要

Double cross-metathesis of 1,5-hexadiene with a variety of electron-deficient alkenes including the reluctant Weinreb acrylamide has been successfully accomplished. It was found that the process is quite general, and microwave irradiation effectively accelerates cross-coupling metathesis. This promotes a very versatile and high yielding methodology for the synthesis of symmetric Michael acceptors, which can be transformed into 2,5-disubstituted pyrrolidines through a sequential one-pot two-directional cross-metathesis/ring- closing double aza-Michael process.