Transition-Metal Free Mechanochemical Approach to Polyyne Substituted Pyrroles

In
this contribution, the synthesis of long chain hexatriynyl-
and octatetraynyl-substituted pyrroles in one step from 1-halopolyyne
precursors is reported. The products were obtained via a mechanochemical
approach by simple grinding of 1-haloalkynes with N-substituted pyrroles and potassium carbonate which played a role
of heterogeneous catalyst and this solvent- and transition metal-free
approach is unprecedent in the synthesis of new, organic, long chain
polyynes. Additionally, an extensive X-ray single crystal study of
pyrrole end-capped polyynes is presented. Such compounds are possible
substrates for different oligoheterocycles and have a significant
application potential such as for instance molecular wires.