Copper-Catalyzed Enantioselective Borylative Allyl-Allyl Coupling of Allenes and Allylic -Dichlorides.

A catalytic asymmetric reaction between allenes, bis(pinacolato)diboron, and allylic -dichlorides is reported. The method involves the coupling of a catalytically generated allyl copper species with the allylic -dichloride and provides chiral internal 1,5-dienes featuring ()-configured alkenyl boronate and alkenyl chloride units with high levels of chemo-, regio-, enantio-, and diastereoselectivity. The synthetic utility of the products is demonstrated with the synthesis of a range of optically active compounds. DFT calculations reveal key noncovalent substrate-ligand interactions that account for the enantioselectivity outcome and the diastereoselective formation of the ()-alkenyl chloride.