Theoretical calculations have been carried out to illustrate the mechanisms and origins of regio/stereoselective hydrosilylation of 1,3-disubstituted allenes catalyzed by Pd and Ni catalysts. Investigations indicated that the mechanisms are divided into three important steps: coordination of silane and allene to the metal center, concerted oxidative addition, and silyl/hydride migration as well as C–H/C–Si bond reductive elimination. We found that concerted oxidative addition is the rate-limiting and regioselective step for the allene-hydrosilylation reaction. Moreover, the utilization of different palladium and nickel catalysts containing N-heterocyclic carbene (NHC) ligands can lead to switchable regioselectivity in allene hydrosilylations. The reaction with Pd–NHC catalysts favors allylsilane products, whereas the reaction with Ni–NHC catalysts affords alkenylsilane products. Intrinsic electronic effects of Pd or Ni catalysts and steric repulsions between catalysts and substrates (silyl and allene) can significantly affect the regioselectivity. These computations are in accordance with observations from experiments and can help to design new palladium and nickel catalysts for the regio/stereoselectivities of allene-hydrosilylation reactions.

中文翻译：

---

DFT研究钯和镍催化的1,3-二取代的烯丙基的区域选择性和立体选择性氢化硅烷化

已经进行了理论计算以说明由Pd和Ni催化剂催化的1，3-二取代的烯的区域/立体选择性氢化硅烷化的机理和起源。研究表明，该机理分为三个重要步骤：硅烷和丙二烯与金属中心的配位，协同的氧化加成，甲硅烷基/氢化物迁移以及C–H / C–Si键的还原性消除。我们发现一致的氧化加成是丙二烯-氢化硅烷化反应的限速和区域选择性步骤。而且，利用包含N-杂环卡宾（NHC）配体的不同钯和镍催化剂可导致丙二烯氢化硅烷化反应中区域选择性的转换。与Pd–NHC催化剂的反应有利于烯丙基硅烷产品，而与Ni–NHC催化剂反应可得到烯基硅烷产物。Pd或Ni催化剂的内在电子效应以及催化剂与底物（甲硅烷基和异戊二烯）之间的空间排斥会显着影响区域选择性。这些计算与实验观察结果一致，可以帮助设计新的钯和镍催化剂，用于丙二烯氢化硅烷化反应的区域/立体选择性。