Regioselective 1,2-insertion of Ru into the C–S bond in 3-substituted thiophenes

Abstract

Reactions of [Ru(cod)(cot)] 1 [cod = cycloocta-1,5-diene, cot = cycloocta-1,3,5-triene] with 3-acetyl(or formyl)thiophene and 2-acetyl(or formyl) thiophene in the presence of depe [1,2-bis(diethylphosphino)ethane] lead to completely regioselective 1,2- or 1,5-insertion into the C–S bond giving the new thiaruthenacycles [Ru(SCRCHCR′CH)(depe)₂] [R = H, R′ = COMe (2a); R = H, R′ = CHO (2b); R = COMe, R′ = H (3a); R = CHO,R′ = H (3b)], respectively.