NIS-Mediated Hofmann-Type Rearrangement to Acyl Isocyanates: A Novel Approach for N-Acylurea Synthesis

A green and efficient method for the assembly of N-acylureas through an NIS-promoted Hofmann-type rearrangement has been described. The advantages of this protocol include mild, metal-free conditions, operational simplicity, broad substrate scope, good functional group tolerance, and high chemoselectivity. The potential practicability and synthetic utility were demonstrated by its easy scalability and application in the concise synthesis of commercial pesticides and drugs. The process of the transformation in our work integrates an unconventional acyl transfer mechanism into the well-established framework of the classical Hofmann rearrangement, which enables the direct conversion of 2-oxoamides to acyl isocyanates.