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An Amine-Assisted Ionic Monohydride Mechanism Enables Selective Alkyne cis-Semihydrogenation with Ethanol: From Elementary Steps to Catalysis

Zhidao Huang, Yulei Wang, Xuebing Leng and Zheng Huang*

*Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China, Email:

Z. Huang, Y. Wang, X. Leng, Z. Huang, J. Am. Chem. Soc., 2021, 143, 4809-4843.

DOI: 10.1021/jacs.1c01472

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The selective synthesis of Z-alkenes in alkyne semihydrogenation relies on the reactivity difference of the catalysts toward the starting materials and the products. In an Ir(III)-catalyzed semihydrogenation with EtOH as hydrogen source, an amine as additive is crucial to promote the alcoholysis. This catalytic system exhibits an unprecedented level of substrate scope, generality, and compatibility.

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proposed reaction pathway

Proposed Ionic Monohydride Mechanism

Transfer Hydrogenation of Alkenes Using Ethanol Catalyzed by a NCP Pincer Iridium Complex: Scope and Mechanism

Y. Wang, Z. Huang, X. Leng, H. Zhu, G. Liu, Z. Huang, J. Am. Chem. Soc., 2018, 140, 4417-4429.

Key Words

semireduction of alkynes, ethanol

ID: J48-Y2021