Affordable Access

Publisher Website

Directing iridium-catalyzed C–C bond formation by selection of the ancillary ligands: Polymerization and cyclotrimerization of alkynes

Authors
Journal
Inorganica Chimica Acta
0020-1693
Publisher
Elsevier
Publication Date
Volume
363
Issue
3
Identifiers
DOI: 10.1016/j.ica.2009.03.030
Keywords
  • Iridium
  • Phosphines
  • Nitrogen Ligands
  • Homogeneous Catalysis
  • Alkynes Polymerization
  • Cyclotrimerization

Abstract

Abstract The ability of organoiridium derivatives of catalyzing oligomerization and polymerization of terminal alkynes is markedly influenced by the nature of non-participative ligands coordinated to the metal. The dimeric species [Ir(cod)Cl] 2 and [Ir(cod)(OMe)] 2 (cod = 1,5-cyclooctadiene) as well as the phosphine complexes HIr(cod)(PR 3) 2 (PR 3 = PPh 3, P( p-MeOC 6H 4) 3, P( o-MeOC 6H 4)Ph 2, PCyPh 2) catalyze the polymerization reaction, whereas the diphosphine derivatives HIr(cod)(P–P) (P–P = Ph 2P(CH 2) n PPh 2 ( n = 1–4), o-C 6H 4(PPh 2) 2) promote the regioselective formation of 1,2,4-trisubstituted benzenes. On the other hand, the iridium complexes with nitrogen chelating ligands Ir(cod)(N–N)X and Ir(hd)(N–N)X (hd = 1,5-hexadiene; N–N = 1,10-phenanthroline and substituted derivatives; X = halogen) catalyze alkynes polymerization. In most cases one catalytic reaction predominates over the other possible routes, so that polymerization often takes place in the absence of oligomerization side reactions, and conversely cyclotrimerization is rarely accompanied by formation of either polyene or dimers.

There are no comments yet on this publication. Be the first to share your thoughts.