Electrochemical Synthesis of 2-Amino-1,3-benzoxazines via TBAI-mediated Desulfurative Cyclization of Isothiocyanates and 2-Aminobenzyl Alcohols.

An efficient one-step protocol has been developed to access a variety of 2-amino-1,3-benzoxazine derivatives via tetrabutylammonium iodide-mediated electrochemical desulfurative cyclization of isothiocyanates and 2-aminobenzyl alcohols. The reaction proceeds through a cycle involving in situ iodine generation, desulfurative cyclization, and iodide regeneration, efficiently forming intermolecular C-O and C-N bonds and affording 2-amino-1,3-benzoxazines in moderate to excellent yields. The practical utility of this strategy is evidenced by its broad substrate scope, good functional group compatibility, scalability to gram-scale synthesis, and metal- and oxidant-free conditions.