Facile access to chiral 1-pyrrolines through Rh-catalyzed enantioselective partial hydrogenation of unprotected simple pyrroles

摘要

Highly enantioselective Rh-catalyzed partial hydrogenation of unprotected simple 2-alkyl-5-aryl-disubstituted pyrroles has been successfully developed,generating a series of chiral 1-pyrroline derivatives generally with excellent results(95%-99%yields,91%-96%ee).Moreover,2,5-aryl-1H-pyrroles were hydrogenated well in high yields and good enantioselectivities.This efficient protocol features easily accessible substrates,wide substrate scope,well functional group compatibility,commercially available rhodium precursor and chiral ligand.It provides a versatile route to access chiral 1-pyrroline derivatives that are of great importance in organic synthesis and pharmaceutical chemistry.