Efficient catalytic enantioselective synthesis of unsaturated amines: Preparation of small- and medium-ring cyclic amines through Mo-catalyzed asymmetric ring-closing metathesis in the absence of solvent

The first catalytic asymmetric ring-closing metathesis method for the synthesis of N-containing heterocycles is reported; this is accomplished through Mo-catalyzed kinetic resolution or desymmetrization of unsaturated amines. Importantly, this catalytic asymmetric method delivers medium-ring unsaturated amines (including eight-membered rings) in high yield, with exceptional enantioselectivity and without the need for solvents. These enantioselective reactions can be effected by catalysts prepared in situ from commercially available reagents.