Activity of homobimetallic ruthenium alkylidene complexes on intermolecular [2+2+2] cyclotrimerisation reactions of terminal alkynes

ÖZTÜRK B. Ö., Karabulut S., İmamoglu Y.

INORGANICA CHIMICA ACTA, cilt.378, sa.1, ss.257-263, 2011 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 378 Sayı: 1
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1016/j.ica.2011.09.023
  • Dergi Adı: INORGANICA CHIMICA ACTA
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.257-263
  • Anahtar Kelimeler: Ruthenium, Cyclotrimerisation, Alkynes, Silicon, Arene ligands, CATIONIC RHODIUM(I)/MODIFIED BINAP, REGIOSELECTIVE CYCLOTRIMERIZATION, ORGANIC-SYNTHESIS, ATOM ECONOMY, CYCLOADDITION REACTIONS, BENZENE-DERIVATIVES, CONSTRUCTION, 1,6-DIYNES, CATALYST, NICKEL
  • Hacettepe Üniversitesi Adresli: Evet

Özet

The activity of homobimetallic ruthenium alkylidene complexes, [(p-cymene)Ru(Cl)(mu-Cl)(2)Ru(Cl) (=CHPh)(PCy(3))] [Ru-I] and [(p-cymene)Ru(Cl)(mu-Cl)(2)Ru(Cl)(=CHPh)(IPr)] [Ru-II], on intermolecular [2+2+2] cyclotrimerisation reactions of monoynes has been investigated for the first time. It was found that these complexes can catalyse the chemo and regioselective cyclotrimerisation reactions of alkynes at both 25 and 50 degrees C in polar, aprotic solvents. The catalytic activity of [Ru-I] and [Ru-II] was compared to other well-known ruthenium catalysts such as Grubbs first generation catalyst [RuCl(2)(=CHPh)(PCy(3))(2)] [Ru-III], [RuCl(mu-Cl)(p-cymene)](2) [Ru-IV] and [RuCl(2)(p-cymene)PCy(3)] [Ru-V] complexes. To examine the effect of the steric hinderance of substrates on the regioselectivity of the reaction, a series of sterically hindered silicon containing alkynes (1a, 1b, 1c) were used. It was shown that the isomeric product distribution of the reaction shifts from 1,2,4-trisubstituted arenes to 1,3,5-trisubstituted arenes as the steric hinderance on the substrates increases. These homobimetallic ruthenium alkylidene complexes also catalysed regio- and chemo-selective cross-cyclotrimerisation reactions between silicon-containing alkynes (1a, 1b, 1c) and aliphatic alkynes (1d-g). (C) 2011 Elsevier B.V. All rights reserved.