Recently the Leigh group have disclosed a novel method of rotaxane synthesis which we have named the active template approach.  This methodology is so named due to the active role the template plays in bond formation.  

In addition to our further investigations of the “click” reaction shown, here we disclose the extension of this approach to other bond forming reactions including palladium, nickel and copper mediated carbon-carbon bond formation, and lewis acid activated addition of enolates to electron deficient double bonds.  These new reactions further exemplify the power of the active template approach: yields ranging from good to quantitative, the ability to use sub-stochiometric quantities of metal template and still achieve high yields, and the synthesis of rotaxanes containing no strong attractive interactions between mechanically bonded components i.e. rotaxanes that can not be accessed directly in any other way.  In some cases active template reactions can also provide mechanistic insight.