Palladium-catalyzed reactions of vinyl bromides with disubstituted alkynes: a new synthesis of fulvenes

Article abstract of DOI:10.1016/0022-328X(91)80026-G

The palladium-catalyzed reaction of vinylic bromides with disubstituted acetylenes at 100 deg C in the presence of trietylamine produces penta- or hexa-substituted fulvenes in low to moderate yields.Reactions with 3-hexyne under the same conditions usually yield dialkylidenecyclopentenes as products, apparently by rearrangement of the expected fulvenes.Fulvenes formed from the reactions of disubstituted alkynes with Z-2-bromovinyl ethyl ether can be hydrolyzed to produce cyclopentadiene carboxaldehydes.