Nitro-Assisted Brønsted Acid Catalysis: Application to a Challenging Catalytic Azidation
作者:Marian Dryzhakov、Malik Hellal、Eléna Wolf、Florian C. Falk、Joseph Moran
DOI:10.1021/jacs.5b06055
日期:2015.8.5
broad range of substrates. Kinetic investigations into this surprising effect reveal that nitro compounds induce a switch from first order concentration dependence in Brønsted acid to second order concentration dependence in Brønsted acid and second order dependence in the nitro compounds. Kinetic, electronic, and spectroscopic evidence suggests that higher order hydrogen-bonded aggregates of nitro compounds
描述了硝基化合物的助催化作用,用于 B(C6F5)3·H2O 催化脂肪叔醇的叠氮化反应,首次实现催化剂周转,并具有广泛的底物。对这种令人惊讶的效应的动力学研究表明,硝基化合物诱导从布朗斯台德酸的一级浓度依赖性转变为布朗斯台德酸的二级浓度依赖性和硝基化合物的二级依赖性。动力学、电子和光谱证据表明,硝基化合物和酸的高阶氢键聚集体是动力学上有能力的布朗斯台德酸催化剂。特定的弱氢键接受添加剂可能提供一种新的通用方法来加速溶液中的布朗斯台德酸催化。