Three-Coordinate Copper(II) Alkynyl Complex in C–C Bond Formation: The Sesquicentennial of the Glaser Coupling
作者:Abolghasem Bakhoda、Otome E. Okoromoba、Christine Greene、Mahdi Raghibi Boroujeni、Jeffery A. Bertke、Timothy H. Warren
DOI:10.1021/jacs.0c07137
日期:2020.10.28
Copper(II) alkynyl species are proposed as key intermediates in numerous Cu-catalyzed C-C coupling reactions. Supported by a β-diketiminate ligand, the three coordinate copper(II) alkynyl [CuII]-C≡CAr (Ar = 2,6-Cl2C6H3) forms upon reaction of the alkyne H-C≡CAr with the copper(II) tert-butoxide complex [CuII]-OtBu. In solution, this [CuII]-C≡CAr species cleanly transforms to the Glaser coupling product
铜 (II) 炔基物质被提议作为众多 Cu 催化的 CC 偶联反应的关键中间体。在 β-二酮亚胺配体的支持下,炔烃 HC≡CAr 与叔丁醇铜 (II) 反应形成三配位铜 (II) 炔基 [CuII]-C≡CAr (Ar = 2,6-Cl2C6H3)络合物[CuII]-OtBu。在溶液中,这种 [CuII]-C≡CAr 物种干净地转化为 Glaser 偶联产物 ArC≡CC≡CAr 和 [CuI](溶剂)。将亲核试剂 R'C≡C-Li(R' = 芳基,甲硅烷基)和 Ph-Li 添加到 [CuII]-C≡CAr 中,得到相应的 Csp-Csp 和 Csp-Csp2 偶联产物 RC≡CC≡CAr 和 Ph- C≡CAr 伴随生成 [CuI](溶剂)和 [CuI]-C≡CAr}-。在 DFT 计算的支持下,氧化还原歧化形成 [CuIII](C≡CAr)(R) 物种,可还原消除 RC≡CAr 产物。[CuII]-C≡CAr