Mild Friedel–Crafts Reactions inside a Hexameric Resorcinarene Capsule: C−Cl Bond Activation through Hydrogen Bonding to Bridging Water Molecules

다국어 초록 (Multilingual Abstract)

A novel catalytic feature of a hexameric resorcinarene capsule is highlighted. The self‐assembled cage was exploited to promote the Friedel–Crafts benzylation of several arenes and heteroarenes with benzyl chloride under mild conditions. Calculations showed that there are catalytically relevant hydrogen‐bonding interactions between the bridging water molecules of the capsule and benzyl chloride, which is fundamental for the activation of the C−Cl bond. The capsule controls the reaction outcome. Inside the inner cavity of the capsule, N‐methylpyrrole is preferentially benzylated in the unusual β‐position while mesitylene reacts faster than 1,3‐dimethoxybenzene despite the greater π‐nucleophilicity of the latter compound.
Spuren von Wasser werden für die Friedel‐Crafts‐Benzylierung von π‐Nucleophilen in einem Resorcinaren‐Hexamer benötigt. Die C‐Cl‐Bindung von BnCl wird durch H‐Brücken zu überbrückenden Wassermolekülen in der Kapsel aktiviert. Diese kontrolliert den Ausgang der Reaktion: N‐Methylpyrrol wird ungewöhnlicherweise bevorzugt in der β‐Position benzyliert, während Mesitylen schneller als 1,3‐Dimethoxybenzol reagiert.