Orthogonal Recognition Processes Drive the Assembly and Replication of a [2]Rotaxane

• Published in: Journal of the American Chemical Society 2015-12, Vol.137 (51), p.16074-16083
• Main Authors: Kosikova, Tamara, Hassan, Nurul Izzaty, Cordes, David B, Slawin, Alexandra M. Z, Philp, Douglas
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.5b09738

Within a small, interconnected reaction network, orthogonal recognition processes drive the assembly and replication of a [2]­rotaxane. Rotaxane formation is governed by a central, hydrogen-bonding-mediated binding equilibrium between a macrocycle and a linear component, which associate to give a reactive pseudo­rotaxane. Both the pseudo­rotaxane and the linear component undergo irreversible, recognition-mediated 1,3-dipolar cycloaddition reactions with a stoppering maleimide group, forming rotaxane and thread, respectively. As a result of these orthogonal recognition-mediated processes, the rotaxane and thread can act as auto-catalytic templates for their own formation and also operate as cross-catalytic templates for each other. However, the interplay between the recognition and reaction processes in this reaction network results in the formation of undesirable pseudo­rotaxane complexes, causing thread formation to exceed rotaxane formation in the current experimental system. Nevertheless, in the absence of competitive macrocycle-binding sites, realization of a replicating network favoring formation of rotaxane is possible.