Highly Z-Selective Synthesis of Highly Substituted 1,3-Oxathiolane-2-imines via TfOH-Catalyzed Formal [3+2] Cycloaddition of Donor-Acceptor Oxiranes and Isothiocyanates

摘要

TfOH-catalyzed [3+2] cycloaddition of donor-acceptor oxiranes with isothiocyanates via chemoselective C-bond breakage of D-A oxiranes was developed under metal-and additive-free conditions. This method providing a facile access to a diverse range of highly substituted 1,3-oxathiolane-2-imines in good to excellent yields and with high Z-selectivity and excellent functional group tolerance. In addition, the established proto- col can be easily scaled up to gram level in excellent yield.