Palladium-catalyzed regioselective cyclopropanating allenylation of (2,3-butadienyl)malonates with propargylic carbonates and their application to synthesize cyclopentenones.Org Lett. 2009 Jan 01; 11(1):117-20.OL
An efficient and highly regioselective route to synthesize polysubstituted 1,3,4-alkatrien-2-yl cyclopropane derivatives via Pd(0)-catalyzed highly regioselective coupling cyclization of (2,3-butadienyl)malonate or bis(phenylsulfonyl)methane with propargylic carbonates was reported. The reaction proceeded smoothly under neutral conditions to afford the products in 73-96% yields. The products may be efficiently converted to cyclopentenone derivatives via a catalytic Pauson-Khand reaction under ambient conditions.