A method for the copper-catalyzed borylmethylation and borylation of vinyl cyclic carbonates through an SN2’ mech- anism is reported. These singular reactions involve selective SN2’ 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 accessed.