Synthesis of Isothiocyanates and Unsymmetrical Thioureas with the Bench-Stable Solid Reagent (Me₄N)SCF₃

A highly efficient, selective, and rapid transformation of primary amines and diamines to isothiocyanates and cyclic thioureas is disclosed. As opposed to established approaches that employ toxic or volatile electrophilic liquids and require reaction control (i.e., slow addition, cooling), this protocol utilizes the bench-stable, solid reagent (Me₄N)SCF₃ at room temperature. The method is characterized by operational simplicity, high speed, efficiency, high functional group tolerance, and late-stage applicability. The byproducts are solids, allowing isolation of the target compounds by filtration.