Palladium-catalyzed tandem cyclization/sulfonylation of homoallenyl amides with sodium sulfinates

Abstract

A palladium-catalyzed cyclizative sulfonylation of homoallenyl amides using sodium sulfinates as the sulfonylation reagent and PhI(O₂CCF₃)₂ as the oxidant has been realized. The reaction proceeds at room temperature and produces structurally diverse 2-amino-5-sulfonylmethylfurans in good to excellent yields. A Pd(II)/Pd(IV) catalytic cycle has been proposed for the formation of sulfonylated furans. The concurrent formation of a furan moiety and a C(sp³)–sulfur bond in a single operation makes it a very attractive method for organic synthesis.