This study investigates the synthesis of unsymmetrical ureas involving tetra‐ n ‐butylammonium fluoride (TBAF) catalyzed in situ generation of isocyanate of N ‐alkyl/aryl O ‐phenyl carbamates at room temperature that subsequently reacts with alkyl/aromatic amines to yield unsymmetrical urea with moderate to excellent yields including gram scale synthesis of celiprolol intermediate. The process of employing TBAF an organocatalyst, thus, eliminates the use of hazardous reagents, hence making the process sustainable, cost‐effective, and additive free.
Singh et al. (Fri,) studied this question.