Insight into the Metal‐free Reduction of Isocyanates to N‐methyl Anilines at Room Temperature

A simple and sustainable protocol has been developed to reduce isocyanates to the N‐methyl anilines under metal‐free conditions. The reaction proceeds with BF3·OEt2 as a catalyst and ammonia borane as a hydrogen source in THF at room temperature, leading to the formation of a wide range of substituted aniline derivatives. Control experiments and deuterium labeling studies were performed to understand the mechanism of the present procedure. A detailed computational study was also conducted to shed light on the possible mechanism and free energies of the intermediates and transition states involved in this present protocol.