Catalytic oxidative carbonylation of aliphatic secondary amines to tetrasubstituted ureas

Abstract

Secondary amines can be catalytically carbonylated to symmetrical tetrasubstituted ureas using W(CO)6 as the catalyst, I2 as the oxidant, and CO as the carbonyl source. Preparation of the corresponding tetrasubstituted ureas from the aliphatic secondary amines HNR2 (R = C2H5, n-Bu, i-Pr, PhCH2) and HNRR' (R,R' = -(CH2)4-; -(CH2)5-; PhCH2, CH3) was achieved in moderate yields. Aromatic secondary amines are unreactive. (C) 2000 Elsevier Science B.V.