Halogen‐Free Synthesis of Carbamates from CO₂ and Amines Using Titanium Alkoxides

Abstract

Abstract A direct synthesis of carbamates from amines and carbon dioxide in the presence of Ti(OR) 4 (R= n Bu ( 1 ), Me ( 2 ), Et ( 3 ), n Pr ( 4 )) was investigated. Aniline was reacted with titanium n ‐butoxide ( 1 ) in the presence of carbon dioxide (5 MPa) to give the corresponding n ‐butyl N ‐phenylcarbamate (BPC) in nearly quantitative yield (99 %) within 20 min. Furthermore, 1 could be regenerated upon reaction with n ‐butanol during water removal. The recovered 1 could then be reused in a subsequent reaction.