Monoalkylation of aniline can be readily achieved using trichloroacetimidate as an alkylating agent and a Brønsted acid, such as (±)-camphorsulfonic acid, as a catalyst. In this study, systematic theoretical calculations were performed to understand the reaction mechanism for the monoalkylation of 2,5-dichloroaniline with trichloroacetimidate catalyzed by (±)-camphorsulfonic acid; moreover, the judgement about whether the reaction takes place via an S_N1 or S_N2 mechanism was elaborated. The two possible proton-transfer reaction mechanisms proposed herein based on the experimental results were investigated; moreover, another two possible reaction mechanisms involving the activation of both 2,5-dichloroaniline and trichloroacetimidate by (±)-camphorsulfonic acid via dual hydrogen-bonding activation modes were evaluated. The calculated results suggest that the reaction between 2,5-dichloroaniline and trichloroacetimidate catalyzed by (±)-camphorsulfonic acid preferentially occurs through the S_N1 mechanism based on the dual hydrogen-bonding activation modes.

中文翻译：

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（±）-樟脑磺酸通过双氢键激活方式的SN1反应催化苯胺与三氯乙酰亚胺的单烷基化

使用三氯乙酰亚胺酸酯作为烷基化剂，并使用布朗斯台德酸，例如（±）-樟脑磺酸，作为催化剂，可以轻松实现苯胺的单烷基化。在这项研究中，进行了系统的理论计​​算以了解2,5-二氯苯胺与（±）-樟脑磺酸催化的三氯乙酰亚氨酸单烷基化的反应机理。此外，通过S _N 1或S _N判断反应是否发生阐述了2个机制。根据实验结果，对本文提出的两种可能的质子转移反应机理进行了研究。此外，还评估了另外两种可能的反应机理，涉及通过双氢键活化方式通过（±）-樟脑磺酸活化2，5-二氯苯胺和三氯乙酰亚胺酸酯。所计算出的结果表明，2,5-二氯苯胺和三氯乙酰亚胺酯由（±） -樟脑磺酸催化的反应通过S优先发生_Ñ基于双氢键的激活模式1家机构。