Cyclotrimerisation catalytique d'alcynes par des complexes du nickel formés “in situ”

Abstract

Catalytic cyclotrimerization of acetylenic compounds by transient complexes formed in the reduction of nickel halides by magnesium, occurs with many alkynes; however, this cyclization is hindered when bulky groups are close neighbors of the triple bond or when acceptor groups are in the α position with respect to the unsaturated carbon. On the other hand, the yield of trimer increases to become quantitative with releasing substituents.