Abstract：
Neighboring group participation, the assistance of non-conjugated electrons to a reaction center, is a fundamental phenomenon in chemistry. In the framework of nucleophilic substitution reactions, neighboring group participation is known to cause rate acceleration, first order kinetics (SN1), and retention of configuration. The latter phenomenon is a result of double inversion: the first one when the neighboring group displaces the leaving group, and the second when a nucleophile substitutes the neighboring group. This powerful control of stereoretention has been widely used in organic synthesis for more than a century. However, neighboring group participation may also lead to inversion of configuration, a phenomenon which is often overlooked. Herein, we review this unique mode of stereoinversion, dividing the relevant reactions into three classes with the aim to introduce a fresh perspective on the different modes of stereoinversion via neighboring group participation as well as the factors that control this stereochemical outcome.
摘要：
邻组参与,非共轭电子对反应中心的帮助，是化学中的一个基本现象。在亲核取代反应的框架中，已知邻近的群体参与会导致速率加速，一级动力学(SN1)，和配置的保留。后一种现象是双重反转的结果：第一个是当相邻组取代离开组时，和第二个当亲核试剂取代相邻基团时。这种强有力的立体留着控制已经在有机合成中广泛使用了一个多世纪。然而,相邻群体参与也可能导致配置倒置，一个经常被忽视的现象。在这里，我们回顾了这种独特的立体倒置模式，将相关反应分为三类，目的是通过邻近群体的参与以及控制这种立体化学结果的因素，对立体倒置的不同模式提出新的看法。
