Controlling the Reactivity of a Metal-Hydroxo Adduct with a Hydrogen Bond
作者:Adedamola A. Opalade、Logan Hessefort、Victor W. Day、Timothy A. Jackson
DOI:10.1021/jacs.1c06199
日期:2021.9.22
(MnLOX) and manganese superoxidedismutase (MnSOD) utilize mononuclear Mn centers to effect their catalytic reactions. In the oxidized MnIII state, the activesite of each enzyme contains a hydroxo ligand, and X-ray crystal structures imply a hydrogen bond between this hydroxo ligand and a cis carboxylate ligand. While hydrogen bonding is a common feature of enzyme activesites, the importance of this
锰脂氧合酶 (MnLOX) 和锰超氧化物歧化酶 (MnSOD) 利用单核 Mn 中心来影响它们的催化反应。在氧化的 Mn III状态下,每种酶的活性位点都包含一个羟基配体,X 射线晶体结构暗示该羟基配体和顺式羧酸盐配体之间存在氢键。虽然氢键是酶活性位点的一个共同特征,但这种特殊的羟基-羧酸盐相互作用的重要性相对来说还没有被探索过。在本研究中,我们检查了一对仅由一个官能团不同的 Mn III -羟基配合物。这些配合物之一,[Mn III (OH)(PaPy 2 N)] +,含有能够与羟基配体形成分子内氢键的萘啶基部分。第二种配合物 [Mn III (OH)(PaPy 2 Q)] +含有一个不允许任何分子内氢键合的喹啉基部分。这些配合物的光谱表征支持一个共同的结构,但对[Mn III (OH)(PaPy 2 N)] +有扰动,与氢键一致。使用具有活化 O-H 键的各种底物的动力学研究表明,[Mn
Copper-Catalyzed [5 + 1] Annulation of 2-Ethynylanilines with an <i>N</i>,<i>O</i>-Acetal Leading to Construction of Quinoline Derivatives
A novel copper-catalyzed [5 + 1] annulation of 2-ethynylanilines with an N,O-acetal, which functioned as a Cl part, leading to the preparation of quinoline derivatives with an ester substituent on the 2-position is described. A combination of CuBr2 and trifluoroacetic acid (TFA) promoting [5 + 1] annulation of the 2-ethynylaniline with ethyl glyoxylate is also demonstrated.