Allosteric regulation is exploited by biological systems to regulate the activity and/or selectivity of enzymatic reactions but remains a challenge for artificial catalysts. Here we report switchable terpy(Zn-salphen)₂ molecular tweezers and their metal-dependent allosteric regulation of the acetylation of pyridinemethanol isomers. Zinc-salphen moieties can both act as a Lewis acid to activate the anhydride reagents and provide a binding site for pyridinemethanol substrates. The tweezers’ conformation can be reversibly switched between an open and a closed form by a metal ion stimulus. Both states offer distinct catalytic profiles, with closed tweezers showing superior catalytic activity towards ortho substrates, while open tweezers presenting higher rate for the acetylation of meta and para substrates. This notable substrate dependent allosteric response is rationalized by a combination of experimental results and calculations supporting a bimetallic reaction in the closed form for ortho substrate and an inhibition of the cavity for meta and para substrates.

生物系统利用变构调节来调节酶促反应的活性和/或选择性，但是对于人工催化剂仍然是一个挑战。在这里，我们报告可转换的terpy（Zn-salphen）₂分子镊子和它们的吡啶甲醇异构体的乙酰化的金属依赖性变构调节。锌-沙芬部分既可以充当路易斯酸来活化酸酐试剂，又可以提供吡啶甲醇底物的结合位点。镊子的构象可以通过金属离子刺激在打开和关闭形式之间可逆地切换。两种状态均提供了独特的催化特性，封闭的镊子对邻位底物表现出优异的催化活性，而开放的镊子则表现出较高的乙酰化率。元和对位底物。这个显着的衬底依赖性变构响应通过试验的结果和计算支撑在闭合形式的双金属反应的组合合理化邻基底和腔的用于抑制元和对位的基板。