Construction of Quaternary Stereogenic Carbon Centers through Copper- Catalyzed Enantioselective Allylic Cross- Coupling with Alkylboranes**

A combination of an in situ generated chiral Cu-I/DTBM-MeO-BIPHEP catalyst system and EtOK enabled the enantioselective S(N)2-type allylic cross-coupling between alkylborane reagents and ,-disubstituted primary allyl chlorides with enantiocontrol at a useful level. The reaction generates a stereogenic quaternary carbon center having three sp(3)-alkyl groups and a vinyl group. This protocol allowed the use of terminal alkenes as nucleophile precursors, thus representing a formal reductive allylic cross-coupling of terminal alkenes. A reaction pathway involving addition/elimination of a neutral alkylcopper(I) species with the allyl chloride substrate is proposed.