Gold-catalyzed rearrangement of propargylic tert-butyl carbonates

Diversely substituted 4-alkylidene-1,3-dioxolan-2-ones are efficiently synthesized by a gold(I)-catalyzed rearrangement of propargylic tert-butyl carbonates. The substrates are readily accessible and the transformation, which is performed under mild reaction conditions using a low loading of catalyst, allows the synthesis of cyclic carbonates, which would be less efficiently obtained using traditional methods. This procedure has also been applied to the stereoselective synthesis of (E)- or (Z)-4-halomethylene-1,3-dioxolan-2-ones, which proved to be suitable substrates for palladium-catalyzed cross-coupling reactions.