Department of Chemistry , University of California-Riverside , Riverside , California 92521 , United States.
J Org Chem. 2019 Sep 20;84(18):12000-12008. doi: 10.1021/acs.joc.9b01880. Epub 2019 Sep 6.
A self-assembled FeL cage is capable of co-encapsulating multiple carboxylic acid containing guests in its cavity, and these acids can act as cofactors for cage-catalyzed nucleophilic substitutions. The kinetics of the substitution reaction depend on the size, shape, and binding affinity of each of the components, and small structural changes in guest size can have large effects on the reaction. The host is quite promiscuous and is capable of binding multiple guests with micromolar binding affinities while retaining the ability to effect turnover and catalysis. Substrate binding modes vary widely, from simple 1:1 complexes to 1:2 complexes that can show either negative or positive cooperativity, depending on the guest. The molecularity of the dissociative substitution reaction varies, depending on the electrophile leaving group, acid cofactor, and nucleophile size: small changes in the nature of substrate can have large effects on reaction kinetics, all controlled by selective molecular recognition in the cage interior.
一个自组装的 FeL 笼能够在其空腔中共同包裹多个含有羧酸的客体，这些酸可以作为笼催化亲核取代反应的辅因子。取代反应的动力学取决于每个组分的大小、形状和结合亲和力，客体大小的微小结构变化会对反应产生很大的影响。主体非常混杂，能够以微摩尔亲和力结合多个客体，同时保持进行周转和催化的能力。底物的结合模式差异很大，从简单的 1:1 配合物到 1:2 配合物，它们可以显示负或正协同作用，这取决于客体。离解取代反应的分子数取决于亲电试剂离去基团、酸辅因子和亲核试剂的大小：底物性质的微小变化会对反应动力学产生很大影响，这一切都由笼内的选择性分子识别控制。
