We report a chemoselective, phosphine-catalyzed semireduction of primary and secondary propiolamides. In the presence of stoichiometric pinacolborane and catalytic n-tributylphosphine, a variety of propiolamides were successfully converted to the corresponding acrylamides in excellent yield with (E)-stereoselectivity. The reaction condition is tolerant of various functional groups including alkene
我们报告了初级和次级丙酰胺的
化学选择性、膦催化的半还原反应。在
化学计量的
频哪醇硼烷和催化正
三丁基膦的存在下,各种丙酰胺以优异的收率成功转化为相应的
丙烯酰胺,具有(E)-立体选择性。反应条件可以容忍各种官能团,包括烯烃、
炔烃、酮或酯。
氘标记研究表明,来自活化
频哪醇硼烷的
氢化物被添加到 α-碳,酰胺氮上的质子被 β-碳提取以提供 ( E )-
丙烯酰胺。DFT 计算揭示了 ( E )- 在 ( Z)-异构体。