Copper-Mediated SN2′ Allyl-Alkyl and Allyl-Boryl Couplings of Vinyl Cyclic Carbonates

A method for the copper-catalyzed borylmethylation and borylation of vinyl cyclic carbonates through an S(N)2' mechanism is reported. These singular reactions involve selective S(N)2' allylic substitutions with concomitant ring opening of the cyclic carbonate and with extrusion of CO2 and formation of a useful hydroxyl functionality in a single step. The stereoselectivity of the homoallylic borylation and allylic borylation processes can be controlled, and synthetically useful unsaturated (E)-pent-2-ene-1,5-diols and (E)-but-2-ene-1,4-diols are accessed.