Asymmetric Oxa-Diels-Alder Reaction Catalyzed by a TetrahedralChiral-at-Zinc Complex with a Tridentate Achiral Ligand

摘要

Development of chiral catalysts has provided easy and efficient access to constructhomochiral molecular scaffolds that are ubiquitous in the fine chemical and pharmaceuticalindustries.For asymmetric reactions using chiral metal-complex catalysts,in general,thechirality results from the chiral ligand bound to the metal center.However,metal center itselfcan act not only as a catalytic center but also as a chiral source due to the space arrangementand symmetry of ligands.This type of catalyst is called"Chiral-at-metal catalyst”,which canbe prepared from relatively simple,achiral and unsymmetrical ligands.