Palladium-catalyzed multi-component Heck alkynylcarbonylation of unactivated alkenes for synthesis of β,γ-alkynoates†
Abstract
Controlling the selectivity of reactions of palladium catalysts with various substrates is challenging. Herein, a general and unprecedented Pd-catalysed four-component inter-molecular Heck alkynylcarbonylation involving haloalkynes, alkenes, carbon monoxide (CO) and alcohols based on a molecular queuing strategy is presented. This efficient methodology proceeds via overall multiple Csp–Csp3 bond and C–O bond formations and provides a divergent approach for the efficient and selective construction of multi-substituted β,γ-alkynoates under mild reaction conditions. Experimental and density functional theory calculation results demonstrate that high selectivity olefin insertion and the following CO insertion are crucial catalytic steps.