Density functional theory (DFT) calculations were performed to investigate a known diamido bis(amidate) Ti precatalyst that is excellent for anti-Markovnikov selective alkyne hydroamination. The coordination environments provided by the hemilabile amidate ligands were studied to reveal their spatial and electronic influence on the structures and energies of intermediates and transition states. Several factors contribute to the unique regioselectivity of this catalytic system, including orbital interactions, ligand coordination modes, and steric repulsion. The turnover-limiting step was found to be substrate-dependent. Experimental evidence was obtained to further test computationally generated hypotheses. These investigations show that the bis(amidate) Ti catalytic system’s high regioselective performance can be attributed to ligand hemilability, which promotes metal–ligand cooperativity in the reaction mechanism.

中文翻译：

---

钛催化反马尔科夫尼科夫加氢胺化反应中的金属-配体协同作用

进行密度泛函理论（DFT）计算以研究一种已知的重氨基二（双（氨基甲酸酯）Ti）预催化剂，该催化剂对抗马尔可夫尼科夫选择性炔烃加氢胺化反应非常出色。研究了半可变酰胺化物配体提供的配位环境，以揭示它们对中间体和过渡态的结构和能量的空间和电子影响。有几个因素促成该催化系统的独特区域选择性，包​​括轨道相互作用，配体配位模式和空间排斥。发现周转限制步骤是底物依赖性的。获得了实验证据以进一步检验计算得出的假设。这些研究表明，双（氨基甲酸酯）Ti催化体系的高区域选择性性能可归因于配体的半透明性，