Rhodium catalyzed asymmetric hydroformylation of vinylarenes with a diphosphite ligand forming a large chelating ring

摘要

A rhodium complex containing a sixteen membered chelated diphosphite, with the appropriate combination of stereogenic centers, produces ee's above 70% in the hydroformylation of vinylarenes, while a related diastereo-isomeric ligand renders very low ee's because it does not form a chelated species.