Amide-Directed Highly Enantioselective Hydrogenation of Diverse Acyclic Multisubstituted Alkenes Under Mild Conditions

Abstract

Enantioselective hydrogenation of tetrasubstituted alkenes to form 1,2-contiguous stereocenters is a particularly appealing but highly challenging transformation in asymmetric catalysis. Despite the notable progress achieved in enantioselective hydrogenation over the past decades, enantioselective hydrogenation of all-carbon tetrasubstituted alkenes containing multiple alkyl groups remains an unsolved challenge. Here, we report a rhodium-catalyzed highly diastereo- and enantioselective hydrogenation of diverse acyclic multisubstituted alkenes under mild conditions. The coordination assistance of the amide group to the metal center generates a highly active catalyst that effectively overcomes the low reactivity of substrates and precisely controls the stereoselectivity. The generality of this catalyst system is exemplified by its efficacy across at least three types of alkenes including β,γ-unsaturated amides, α,β-unsaturated amides, and enamides.

Keywords: acyclic olefins; asymmetric hydrogenation; contiguous stereocenters; rhodium catalysis; tetrasubstituted alkenes.