Zirconium-mediated intramolecular coupling of terminal alkynes and their subsequent carbonylation: Novel synthesis of seven- and eight-membered heterocycles

Article abstract of DOI:10.1002/chem.19970030820

The development of a new method for the intramolecular coupling of terminal alkynes and for the synthesis of seven- and eight-membered benzoheterocyeles is reported. The key steps involve the generation of zirconocene-alkyne complexes from 2-bromoalkenes and the subsequent intramolecular carbometalation of olefins or acetylides. The 8-unsubstituted zirconabicyclopentenes were carbonylated to afford unexpected products and allow access to polyfunctionalized molecules from simple starting materials.