The heterocyclization of unsaturated nitriles and ethyne catalyzed by
cyclopentadienyl - ١،٥ - cis, cis-cyclooctadiene-cobalt (I) and promoted by light
has been studied in toluene as solvent.
Acrylonitrile and substituted acrylonitriles gave satis
fying results
interesting for the preparation of ٢-vinylpyridines.
No reaction was observed using fumaronitrile, maleonitrile and
allycyanides.
(E)/(Z)-ratio of reactants and products seems not to be influenced within the
reaction.