Catalytic Enantioselective Hydroxylation of Tertiary Propargylic C(sp3)–H Bonds in Acyclic Systems: a Kinetic Resolution Study

Abstract

Direct site-selective and enantioselective oxyfunctionalization of C(sp³)–H bonds to form alcohols with a general scope, with predictable selectivities, and in preparatively useful yields represents a paradigm shift in the standard logic of synthetic organic chemistry. However, the knowledge of either enzymatic or nonenzymatic asymmetric hydroxylation of tertiary C–H bonds for enantioenriched tertiary alcohol synthesis is sorely lacking. Here, we report a practical manganese-catalyzed enantio-differentiating hydroxylation of tertiary propargylic C–H bonds in acyclic systems, producing a wide range of structurally diverse enantioenriched tertiary propargyl alcohols in high efficiency with extremely efficient chemo- and enantio-discrimination. Other features include the use of C–H substrates as the limiting reagent, noteworthy functional group compatibility, great synthetic utilities, and scalability. The findings serve as a blueprint for the development of metal-catalyzed asymmetric oxidation of challenging substrates.