Rhodium-Catalyzed Rearrangement of S/Se-Ylides for the Synthesis of Substituted Vinylogous Carbonates.

An efficient rhodium-catalyzed unprecedented oxa-[2,3]-sigmatropic rearrangement of sulfur ylide derived from α-thioesters/ketones and diazo carbonyl compounds has been accomplished for the synthesis of various sulfur-tethered vinylogous carbonates in good to excellent yields. Important features of the developed reaction include wide functional group tolerance, excellent chemo- and regioselectivity, and efficient rearrangement involving the carbonyl motif. The present reaction also equally works well with α-selenoesters for the synthesis of seleno-containing vinylogous carbonates.