How Does an Earth-Abundant Copper-Based Catalyst Achieve Anti-Markovnikov Hydrobromination of Alkynes? A DFT Mechanistic Study
How Does an Earth-Abundant Copper-Based Catalyst Achieve Anti-Markovnikov Hydrobromination of Alkynes? A DFT Mechanistic Study
复制标题
地球上储量丰富的铜基催化剂如何实现炔烃的反马可夫尼科夫氢溴化？
DOI：
10.1021/acs.organomet.6b00246
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发表时间：
2016-06-13
期刊：
影响因子：
2.8
通讯作者：
Wang, Xiaotai
中科院分区：
文献类型：
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作者：
Deng, Xi;Dang, Yanfeng;Wang, Xiaotai
最近，使用铜（I）N-杂环卡宾（NHC）络合物实现了第一个炔的催化氢卤代反应，并且发现该反应是顺式和反马氏选择性的。目前的工作是密度泛函理论（DFT）计算研究（B3 LYP和M06）的详细机制，这一显着的催化反应。反应开始于酚盐添加剂将预催化剂（NHC）CuCl转化为（NHC）Cu（OAr），其随后与氢化物源Ph 2SiH 2进行金属转移以提供铜（I）氢化物络合物（NHC）CuH。（NHC）CuH通过炔配位和随后的迁移插入Cu-H键进行底物RC CHCH的氢化铜化，形成（E）-（NHC）Cu（CH CHCH）。迁移插入步骤决定了顺式选择性，因为它是通过协调的途径发生的，并且它还决定了由Cu-H和C = C键上的电荷分布引起的反马尔可夫尼科夫区域选择性。溴化剂（BrCl 2C）2是利用溴代...
The first catalytic hydrohalogenation of alkynes was recently achieved using a copper(I) N-heterocyclic carbene (NHC) complex, and the reaction was found to be syn and anti-Markovnikov selective. The present work is a density functional theory (DFT) computational study (B3LYP and M06) on the detailed mechanism of this remarkable catalytic reaction. The reaction begins with a phenoxide additive turning over the precatalyst (NHC)CuCl into (NHC)Cu(OAr), which subsequently transmetalates with the hydride source Ph2SiH2 to deliver the copper(I) hydride complex (NHC)CuH. (NHC)CuH undertakes hydrocupration of the substrate RC≡CH via alkyne coordination and subsequent migratory insertion into the Cu–H bond, forming (E)-(NHC)Cu(CH═CHR). The migratory insertion step determines the syn selectivity because it occurs by a concerted pathway, and it also determines the anti-Markovnikov regioselectivity that arises from the charge distributions across the Cu–H and C≡C bonds. The brominating agent (BrCl2C)2 uses the bromo...