Synthesis of 4-substituted imino-4H-benzo[d][1,3] thiazin-2-amines via palladium-catalysed isocyanide insertion in 2-bromophenylthioureas

Abstract

The palladium-catalysed isocyanide insertion in 2-bromophenylthioureas results in the formation of 4-substituted imino-4H-benzo[d][1,3]thiazin-2-amines via C–S cross coupling reaction of the intermediate imidoylpalladium species. The investigations into the substrate scope revealed that whereas reactions of cyclohexyl isocyanide were successful with aromatic as well as aliphatic thioureas, reactions of all other isocyanides (except ethyl 2-isocyanoacetate) were successful with aromatic thioureas only.