W(CO)6-catalyzed oxidative carbonylation of primary amines to N,N'-disubstituted ureas in single or biphasic solvent systems. Optimization and functional group compatibility studies

JE McCusker; AD Main; KS Johnson; CA Grasso; L McElwee-White

doi:10.1021/jo000364+

W(CO)6-catalyzed oxidative carbonylation of primary amines to N,N'-disubstituted ureas in single or biphasic solvent systems. Optimization and functional group compatibility studies

J Org Chem. 2000 Aug 25;65(17):5216-22. doi: 10.1021/jo000364+.

Authors

JE McCusker¹, AD Main, KS Johnson, CA Grasso, L McElwee-White

Affiliation

¹ Department of Chemistry, University of Florida, Gainesville 32611, USA.

PMID: 10993349
DOI: 10.1021/jo000364+

Abstract

Primary amines undergo carbonylation to N,N'-disubstituted ureas using W(CO)6 as the catalyst, I2 as the oxidant, and CO as the carbonyl source. Preparation of various N,N'-disubstituted ureas from aliphatic primary amines, RNH2 (R = n-Pr, n-Bu, i-Pr, sec-Bu, or t-Bu), was achieved in good to excellent yields. Studies of functional group compatibility using a series of substituted benzylamines demonstrated broad tolerance of functionality during the carbonylation reaction. Preparation of various N,N'-disubstituted ureas from substituted benzylamines, R-C6H4CH2NH2 (R = H, p-OCH3, p-CO2H, p-CO2Et, p-CH2OH, p-SCH3, p-vinyl, p-Cl, p-Br, m-I, p-NH2, p-NO2, or p-CN), was achieved in good yields. For many substituted benzylamines, yields of ureas were higher when a two-phase CH2Cl2/H2O solvent system was used.