Catenane oxidative coupling

However, produced a neutral [2]catenane (Scheme 11.5) [lib] bearing a mechanically interlocked bis-NDI macrocycle in 53% yield. This yield is far more attractive for a bis-NDI macrocycle than the 10% yield originally obtained in macrocycles [30a]. This approach involved an oxidative coupling of two acetylenic naphthalene diimides in the presence of crown ether. The efficiency of the catenation can be attributed to the crown ether component acting as a permanent template for the forming cyclophane. 

Figure 6.4 A dinuclear copper(I)-containing [2]-catenane formed via double acetylene oxidative coupling ...

Figure 11 Principle of the four-reacting centre approach to [3]catenanes. The black triangle represents a terminal acetylenic function able to react with itself in a Glaser oxidative coupling reaction.

Starting from a 1 2 mixture of an electron-rich bis-l,5-(dinaphtho)-38-crown-10 and the electron-poor bis-acetylenic compound 1, Sanders used the template effect obtained by the inclusion of the pyromellitic diimide 1 in the crown ether to direct the oxidative coupling of the terminal alkynes toward the formation of the cyclized structure, the [2]catenane, with a 38% chemical yield. When 1 was replaced by a more electron-poor moiety obtained from 1,4,5,8-naphthalene tetracarboxylic diimide (2, Scheme 17.5) the yield of the catenane improved to 52%. 

Scheme 10.7 Oxidative acetylide coupling in the formation of [3]catenanes 35 and 39 reported by Sauvage and coworkers.

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