Tan Mei-Ling, Ángeles Gutiérrez López M, Sakai Naomi, Matile Stefan
Department of Organic Chemistry, University of Geneva, Geneva, Switzerland.
Angew Chem Int Ed Engl. 2023 Oct 2;62(40):e202310393. doi: 10.1002/anie.202310393. Epub 2023 Aug 25.
Anion-π catalysis operates by stabilizing anionic transition states on π-acidic aromatic surfaces. In anion-(π) -π catalysis, π stacks add polarizability to strengthen interactions. In search of synthetic methods to extend π stacks beyond the limits of foldamers, the self-assembly of micelles from amphiphilic naphthalenediimides (NDIs) is introduced. To interface substrates and catalysts, charge-transfer complexes with dialkoxynaphthalenes (DANs), a classic in supramolecular chemistry, are installed. In π-stacked micelles, the rates of bioinspired ether cyclizations exceed rates on monomers in organic solvents by far. This is particularly impressive considering that anion-π catalysis in water has been elusive so far. Increasing rates with increasing π acidity of the micelles evince operational anion-(π) -π catalysis. At maximal π acidity, autocatalytic behavior emerges. Dependence on position and order in confined micellar space promises access to emergent properties. Anion-(π) -π catalytic micelles in water thus expand supramolecular systems catalysis accessible with anion-π interactions with an inspiring topic of general interest and great perspectives.
阴离子-π催化通过在π酸性芳香表面稳定阴离子过渡态来发挥作用。在阴离子-(π)-π催化中，π堆积增加极化率以增强相互作用。为了寻找将π堆积扩展到折叠体极限之外的合成方法，引入了两亲性萘二亚胺（NDIs）形成的胶束自组装。为了连接底物和催化剂，安装了与超分子化学中的经典物质二烷氧基萘（DANs）形成的电荷转移复合物。在π堆积的胶束中，受生物启发的醚环化速率远远超过有机溶剂中单体的反应速率。考虑到迄今为止水中的阴离子-π催化一直难以捉摸，这尤其令人印象深刻。随着胶束π酸度的增加反应速率提高，表明存在有效的阴离子-(π)-π催化。在最大π酸度时，出现自催化行为。对受限胶束空间中位置和顺序的依赖性有望获得新出现的性质。因此，水中的阴离子-(π)-π催化胶束扩展了通过阴离子-π相互作用可实现的超分子体系催化，这是一个具有普遍意义和广阔前景的令人鼓舞的主题。
