Dynamic covalent synthesis of [2]- and [3]rotaxanes both in solution and on solid supports

Abstract

Here we describe the use of a dynamic covalent synthetic approach to improve the attachement of interlocked architectures to solid supports. Although, dynamic covalent chemistry, and even more specifically disulfide exchange reactions have proved to be a successful synthetic strategy for the synthesis of catenanes and knots, comparatively few examples of its use for the synthesis of rotaxanes have been reported. Our work demonstrates that disulfide exchange can be used to synthesise neutral naphthalene diimide containing rotaxanes. Detailed HPLC analysis enabled deconvolution of a complex equilibrium between 6 disulfide species in solution. Analogous experiments investigating dynamic covalent attachment of rotaxanes to TentaGel™ polymer resins using disulfide chemistry resulted in significantly increased attachment of interlocked architectures attached to the solid supports (65% rotaxane) as compared to traditional (kinetically controlled) synthetic approaches.