Facile Regio- and Stereoselective Hydrometalation of Alkynes with a Combination of Carboxylic Acids and Group 10 Transition Metal Complexes: Selective Hydrogenation of Alkynes with Formic Acid

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• 作者：Ruwei Shen ; Tieqiao Chen ; Yalei Zhao ; Renhua Qiu ; Yongbo Zhou ; Shuangfeng Yin ; Xiangbo Wang ; Midori Goto ; Li-Biao Han
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：October 26, 2011
• 年：2011
• 卷：133
• 期：42
• 页码：17037-17044
• 全文大小：1021K
• 年卷期：v.133,no.42(October 26, 2011)
• ISSN：1520-5126

文摘

A facile, highly stereo- and regioselective hydrometalation of alkynes generating alkenylmetal complex is disclosed for the first time from a reaction of alkyne, carboxylic acid, and a zerovalent group 10 transition metal complex M(PEt₃)₄ (M = Ni, Pd, Pt). A mechanistic study showed that the hydrometalation does not proceed via the reaction of alkyne with a hydridometal generated by the protonation of a carboxylic acid with Pt(PEt₃)₄, but proceeds via a reaction of an alkyne coordinate metal complex with the acid. This finding clarifies the long proposed reaction mechanism that operates via the generation of an alkenylpalladium intermediate and subsequent transformation of this complex in a variety of reactions catalyzed by a combination of Brnsted acid and Pd(0) complex. This finding also leads to the disclosure of an unprecedented reduction of alkynes with formic acid that can selectively produce cis-, trans-alkenes and alkanes by slightly tuning the conditions.