The active template approach to interlocked molecules

The active template approach to interlocked molecules takes advantage of the ability of metal ions to both organize precursor fragments for mechanical bond formation and to mediate the final covalent bond-forming reaction that captures the interlocked structure. Since its inception just a decade ago, this new methodology has expanded rapidly from a single reaction for rotaxane synthesis to a range of metal-mediated bond formations for the synthesis of complex interlocked molecules. In this Review, we introduce the active template concept, its key advantages for the synthesis of interlocked molecules and outline recent advances that have been made using this technology. We will conclude with comments about future directions and challenges. The active template approach to interlocked molecules uses metal ions to both pre-organize reaction components and catalyse the final covalent bond formation that captures the interlocked structure. This Review looks at the history of the method, its application in the synthesis of ever more complex interlocked molecules and future directions.