1,2-Addition <i>versus</i> homoconjugate addition reactions of indoles and electron-rich arenes to α-cyclopropyl <i>N</i>-acyliminium ions: synthetic and computational studies
作者:Greg M. Ryder、Uta Wille、Anthony C. Willis、Stephen G. Pyne
DOI:10.1039/c9ob01363f
日期:——
of these reactions, clearly showing that the 1,2-addition pathway is kinetically controlled. In reactions where the 1,2-adduct is destabilised, for example when the arene ring is less nucleophilic, the 1,2-addition is reversible and the thermodynamically preferred homoconjugate addition and subsequent rearrangement and cyclisation reactions become the major pathway.
对α-环丙基N-酰亚胺离子对吲哚的反应性的研究导致通过1,2-加成反应空前合成5-环丙基-5-(3-吲哚基)吡咯烷二-2-酮,在这种情况下通过在C-5四元立体中心通常进行高非对映选择性控制的顺序同质共轭和1,2-加成反应,制备高度缺乏电子的吲哚和富电子芳烃,螺杂环化合物。计算研究为这些反应的拟议机理和立体化学结果提供了支持,清楚地表明1,2-加成途径是动力学控制的。在1,2-加合物不稳定的反应中,例如,当芳烃环的亲核性较低时,1,