Carbamoyl complexes as a source of isocyanates or carbamyl chlorides

Abstract

Isocyanates or carbamyl chlorides have been prepared by reaction of carbamoyl complexes of nickel and palladium with CuCl 2. Isocyanates are selectively produced from the carbamoyl complexes of primary amines, [LNiCl(CONHR)], (L = 2,6-bis(diphenyl-phosphinomethyl) pyridine; R = C 6H 5, p-CH 3C 6H 4, or p-ClC 6H 4)) and [Pd(PPh 3) 2Cl(CONHCH 2COOCH 3)], whereas carbamoyl complexes of secondary amines, such as [Pd(PPh 3) 2Cl(CO N(CH 2) 4C H 2)], afford carbamyl chloride. As expected, the reaction of the resulting isocyanates or carbamyl chlorides in situ with alcohols or amines produces carbamates or N, N′-substituted ureas, respectively.