The mechanism of selenium-catalyzed allylic amination reactions with different ligands has been explored using density functional theory calculations. The mechanism consists of the generation of the key active catalyst selenium bis(imide), an ene reaction, a [2,3]-sigmatropic shift, and ligand-assisted hydrogen transfer. The ene reaction step plays a critical role in determining the regioselectivity of the reaction. Under two different catalytic conditions (Cy₃PSe and IMeSe), OPCy₃ and OIMe were identified as the most optimal ligands. The computational results indicate that the ene reaction does not occur through a simultaneous ligand dissociation process but rather proceeds in a stepwise manner where the ligand dissociates before engaging in the ene reaction with the substrate. Furthermore, the regioselectivity mainly originates from the orbital interaction for acyclic trisubstituted alkenes and the distortion energy for cyclic trisubstituted alkenes.

中文翻译：

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硒催化的烯丙基胺化反应区域选择性的机制和来源


使用密度泛函理论计算探讨了硒催化的烯丙基胺化反应与不同配体的机制。该机制包括关键活性催化剂双硒（酰亚胺）的产生、烯反应、[2,3]-σ-sigmatropic shift 和配体辅助氢转移。ene 反应步骤在确定反应的区域选择性方面起着关键作用。在两种不同的催化条件 （Cy₃PSe 和 IMeSe） 下，OPCy₃ 和 OIMe 被确定为最佳配体。计算结果表明，烯反应不是通过同时进行的配体解离过程发生的，而是以逐步的方式进行，其中配体在与底物进行烯反应之前解离。此外，区域选择性主要来源于非环三取代烯烃的轨道相互作用和环状三取代烯烃的畸变能。