Highly diastereo- and enantioselective Mannich reaction of lactones with N-Boc-aldimines catalyzed by bifunctional rosin-derived amine thiourea catalysts

A highly efficient diastereo- and enantioselective Mannich reaction of lactones with a variety of N-Boc-aldimines by using bifunctional rosin-derived amine thiourea catalysts was investigated for the first time, in general, affording the adducts bearing quaternary stereogenic centers with high levels of enantio-and diastereoselectivity (up to 99% ee, and > 20 : 1 dr).