作者:Hai Dong、Martin Rahm、Niranjan Thota、Lingquan Deng、Tore Brinck、Olof Ramström
DOI:10.1039/c2ob26980e
日期:——
triflate inversion, whereas with neighbouring benzyl ether groups or axial ester groups, mixtures are generally produced. In the present study, the origin of this difference was addressed. The ambident reactivity of the nitrite ion has been found to be the cause of the complex product formation observed, which can be controlled by a neighbouring equatorial ester group. Both N-attack and O-attack occur
在以前的研究中,据报道,相邻的赤道酯基对于亚硝酸盐介导的三氟甲磺酸盐转化的良好收率是必不可少的,而对于相邻的苄基醚基或轴向酯基,通常会产生混合物。在本研究中,解决了这种差异的根源。已发现亚硝酸根离子的环境反应性是观察到形成复杂产物的原因,其可以由相邻的赤道酯基团控制。N-攻击和O-攻击都在不存在酯基的情况下发生,而O-攻击在存在酯基的情况下是有利的。除了空间效应外,还基于邻近酯基团与传入亲核试剂之间的次要相互作用,提出了一种邻近基团辅助机制。为了描述这种影响,进行了高级量子力学计算。理论结果与实验非常吻合,并暗示了对邻近的赤道酯基的催化作用。