Kinetically Trapped Tetrahedral Cages via Alkyne Metathesis

In
dynamic covalent synthesis, kinetic traps are perceived as disadvantageous,
hindering the system from reaching its thermodynamic equilibrium.
Here we present the near-quantitative preparation of tetrahedral cages
from simple tritopic precursors using alkyne metathesis. While the
cages are the presumed thermodynamic sink, we experimentally demonstrate
that the products no longer exchange their vertices once they have
formed. The example reported here illustrates that kinetically trapped
products may facilitate high yields of complex products from dynamic
covalent synthesis.