Mechanistic Studies on the Copper-Catalyzed Hydrosilylation of Ketones
Mechanistic Studies on the Copper-Catalyzed Hydrosilylation of Ketones
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DOI：
10.1002/ejic.200900961
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发表时间：
2010-02-01
影响因子：
2.3
通讯作者：
Bellemin-Laponnaz, Stephane
中科院分区：
文献类型：
--
作者：
Issenhuth, Jean-Thomas;Notter, Francois-Paul;Bellemin-Laponnaz, Stephane
铜催化酮的不对称硅氢加成反应是合成手性仲醇的有效方法。在此，我们提出了一个详细的计算研究（DFT/B3 LYP）的铜（I）催化反应。特别是，参与催化循环的两个过渡态已被确定。发现酮插入到Cu-H键中具有比烷氧基铜中间体与硅烷的反应更低的活化势垒，其沿着甲硅烷基醚产物再生Cu-H。我们的研究结果还揭示了氢化铜二聚体在控制对酮的反应性的重要性。实验机制研究，包括动力学研究，动力学同位素效应，同位素标记测量的结论是支持的。
The copper-catalyzed asymmetric hydrosilylation of ketones is an efficient method for the synthesis of chiral enantiopure secondary alcohols. Herein, we present a detailed computational study (DFT/B3LYP) of the copper(I) -catalyzed reaction. In particular, the two transition states involved in the catalytic cycle have been determined. The insertion of the ketone into the Cu-H bond was found to have a lower activation barrier than the reaction of the copper alkoxy intermediate with the silane, which regenerates Cu-H along with the silyl ether product. Our findings also reveal the importance of the copper hydride dimer in controlling the reactivity toward the ketone. The conclusions are supported by experimental mechanistic investigations including kinetic studies, kinetic isotope effect, and isotope labeling measurements.