Rh-Catalyzed Asymmetric Hydrogenation of Unsaturated Medium-Ring NH Lactams: Highly Enantioselective Synthesis of N-Unprotected 2,3-Dihydro-1,5-benzothiazepinones
Congcong Yin, Tao Yang, Yingmin Pan, Jialin Wen, Xumu Zhang
Abstract
A straightforward method to prepare 1,5-benzothiazepines was reported. Catalyzed by a Rh/Zhaophos complex, unsaturated cyclic NH lactams with a medium-size ring were hydrogenated smoothly, giving remarkably high enantioselectivities. The sulfur atom in the substrates did not bring an inhibition which was observed with commercially available bisphosphine ligands. This method was successfully applied in the scale-up synthesis of (R)-(−)-thiazesim.
Topics & Concepts
ChemistryEnantioselective synthesisCatalysisRing (chemistry)SulfurCombinatorial chemistryAsymmetric hydrogenationMedicinal chemistryStereochemistryOrganic chemistryAsymmetric Hydrogenation and CatalysisSynthesis and Catalytic ReactionsAsymmetric Synthesis and Catalysis