Enzyme-Like Catalysis via Ternary Complex Mechanism: Alkoxy-Bridged Dinuclear Cobalt Complex Mediates Chemoselective O-Esterification over N-Amidation
作者:Yukiko Hayashi、Stefano Santoro、Yuki Azuma、Fahmi Himo、Takashi Ohshima、Kazushi Mashima
DOI:10.1021/ja400367h
日期:2013.4.24
Hydroxy group-selective acylation in the presence of more nucleophilic amines was achieved using acetates of first-row late transition metals, such as Mn, Fe, Co, Cu, and Zn. Among them, cobalt(II) acetate was the best catalyst in terms of reactivity and selectivity. The combination of an octanuclear cobalt carboxylate cluster [Co4(OCOR)6O]2 (2a: R = CF3, 2b: R = CH3, 2c: R = (t)Bu) with nitrogen-containing
在更多亲核胺的存在下,羟基选择性酰化是使用第一排后过渡金属(如 Mn、Fe、Co、Cu 和 Zn)的乙酸盐实现的。其中,乙酸钴(II)在反应性和选择性方面是最好的催化剂。八核羧酸钴簇 [Co4(OCOR)6O]2 (2a: R = CF3, 2b: R = CH3, 2c: R = (t)Bu) 与含氮配体如 2,2' 的组合-联吡啶,为酯交换提供了一种有效的催化体系,其中醇盐桥连的双核复合物 Co2(OCO(t)Bu)2(bpy)2(μ2-OCH2-C6H4-4-CH3)2 (10) 是作为关键中间体成功分离。动力学研究和密度泛函理论计算通过类似于双核金属酶的有序三元复合机制揭示了复合物 10 的 Michaelis-Menten 行为,