作者:William G. Whitehurst、Junho Kim、Stefan G. Koenig、Paul J. Chirik
DOI:10.1021/jacs.2c08865
日期:2022.10.19
structures, [(depe)Co(cycloneophyl)(L)(L′)][BArF4] (depe = 1,2-bis(diethylphosphino)ethane; cycloneophyl = [κ-C:C-(CH2C(Me)2)C6H4]; L/L′ = pyridine, pivalonitrile, or the vacant site, BAr4F = B[(3,5-(CF3)2)C6H3]4). Each of these compounds promoted facile directed C(sp2)–H activation with exclusive selectivity for ortho-alkylated products, consistent with the selectivity of reported cobalt-catalyzed arene-alkene-alkyne
合成了五配位和六配位阳离子双(膦)钴(III)金属环配合物,其一般结构为[(depe)Co(cycloneophyl)(L)(L′)][BAr F 4 ](depe = 1, 2-双(二乙基膦基)乙烷; cycloneophyl = [κ- C : C -(CH 2 C(Me) 2 )C 6 H 4 ];L/L′ = 吡啶、新戊腈或空位,BAr 4 F = B[(3,5-(CF 3 ) 2 )C 6 H 3 ] 4 )。这些化合物均促进了简便的定向 C(sp 2 )–H 活化,对邻位烷基化产物具有独特的选择性,与报道的钴催化芳烃-烯烃-炔烃偶联反应的选择性一致。钴(III)金属环对C-H活化的直接观察为这些化合物在此类催化C-H官能化反应中的中介作用提供了实验支持。氘标记和动力学研究深入了解了可分离钴 (III) 前体中 C-H 键裂解和 C-C 键还原消除的性质。