Solution-Phase Dynamic Assembly of Permanently Interlocked Aryleneethynylene Cages through Alkyne Metathesis

Highly stable permanently interlocked aryleneethynylene molecular cages were synthesized from simple triyne monomers using dynamic alkyne metathesis. The interlocked complexes are predominantly formed in the reaction solution in the absence of any recognition motif and were isolated in a pure form using column chromatography. This study is the first example of the thermodynamically controlled solution-phase synthesis of interlocked organic cages with high stability. All knotted up: Permanently interlocked aryleneethynylene cages were prepared through thermodynamically controlled alkyne metathesis from simple monomers in solution. This template-free approach favors at equilibrium the formation of the interlocked complexes (see picture) over that of independent cages, despite the unfavorable entropy loss associated with catenation.