Alkenyl complexes of iridium and their properties as cyclotrimerization catalysts

Abstract

Reactions of activated, disubstituted acetylenes with IrH(CO)(PPh 3) 3 under various conditions give four-, five-, and six-coordinate alkenyliridium complexes. Some new, novel alkenyl metallocycles containing two different acetylenic units incorporated into the metallocyclopentadiene ring have also been prepared, and these are good catalysts for the cyclotrimerization of disubstituted acetylenes.