SYNTHESIS OF ALKYNYLCYCLOOCTATETRAENES AND ALKYNYLCUBANES

The couplings of a variety of iodocubanes with terminal acetylenes in refluxing NEt3 in the presence of Cu(I) and Pd(0) were examined. The products, isolated in about 50% yield, were not alkynylcubanes but were instead the first examples of alkynyl-1,3,5,7-cyclooctatetraenes. The first examples of alkynylcubanes (cubylacetylenes) were themselves synthesized in modest yield by Negishi's procedure from alkyl cubyl ketones. Cubylacetylenes were shown to be stable under Heck-like coupling conditions and potentially useful thereby for the introduction of the cubylacetylene moiety into complex systems.