在不对称的水合甲基化反应中解开非共价相互作用的重要性
Yuvraj Dangat1, Sahil Popli1, Raghavan B Sunoj1
1Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
这项研究揭示了使用YanPhos配体的催化非对称水合酶的机制,解释了通过非对应相互作用的对抗选择性,并确定了降解性消除作为奇拉性化物生产的关键步骤.
科学领域:
- 有机金属化学
- 不对称的催化
- 计算化学
背景情况:
- 不对称的基形成 (AHF) 对于合成性化物至关重要.
- 目前的AHF方法往往缺乏深度的机械学理解,阻碍了优化.
- 有限的洞察力产生于经验方法.
研究的目的:
- 阐明Rh-{S,S) -催化α-甲基的AHF的机械细节.
- 了解这种催化系统中的反选择性.
- 为改善AHF反应提供分子洞察力.
主要方法:
- 综合密度函数理论 (DFT) 的计算 (ω-B97XD 和 M06).
- 双轴性性YanPhos连接体的详尽形状采样.
- 影响催化剂-基质结合和过渡状态的非共价相互作用 (NCIs) 的分析.
主要成果:
- 非共价相互作用 (C-H··π,π··π,单对··π) 决定了连接体构造和基质结合.
- 对α-甲基与Rh中心的*si*面的首选结合.
- 区域选择性迁移插入有利于线性化物形成 (3.6 kcal/mol差异).
- 乙醇选择性来自于化物添加到*si*面的较低能量过渡状态 (1.5 kcal/mol差异),预测为85% ee.
- 能量跨度分析确定了减少消除作为决定营业额的步骤.
结论:
- 详细介绍了Rh-S,S-催化AHF的机制.
- 非共价相互作用在控制反抗选择性方面起着至关重要的作用.
- 这些发现可以指导各种和工业应用的AHF的开发.
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