[Ir(P-OP)]-Catalyzed Asymmetric Hydrogenation of Diversely Substituted C+N-Containing Heterocycles

Iridium(I) complexes of enantiomerically pure phosphine-phosphite ligands ([Ir(Cl)(cod)(P-OP)]) efficiently catalyze the enantioselective hydrogenation of diverse C=N-contg. heterocyclic compds. (benzoxazines, benzoxazinones, benzothiazinones, and quinoxalinones; 25 examples, up to 99% ee). A substrate-to-catalyst ratio as high as 2000:1 was reached.