Several palladacycle and platinacycle complexes have been prepared from easily available or naturally occurring indole derivatives, such as gramine and related compounds. Dimeric complexes were obtained with Pd(OAc)(2), while Pt(DMSO)(2)Cl-2 mainly afforded monomeric structures. A notable feature of these reactions was the formation of new M-C bonds between Pd or Pt and C-2 and C-3 of the indole ring. With ligands like 2-(2'-pyridyl)-1H-indoles, N-N metallacycles were generated instead: in fact new C-M bonds with the C-3 position could only form if N-substituted indoles were used. The reactivity of Pd dimeric complexes with PPh3, sym-collidine and DMAP was explored to obtain monomeric complexes. Three such compounds were prepared, one of which was characterized by X-ray diffraction. Metathetical reactions were carried out to effect a ligand exchange replacing OAc with halide ions, with the aim to synthesize mu-Cl and mu-Br bridged structures. Turning to the synthesis of hetaryl complexes, functionalization of the C-2 position on the indole ring was achieved. These complexes were prepared by substitution reactions starting from gramine and/or its alkylammonium salts. (c) 2004 Elsevier B.V. All rights reserved.
|Titolo:||Novel cyclometallated Pd(II) and Pt(II) complexes with indole derivatives and their use as catalysts in heck reaction|
DEMARTIN, FRANCESCO (Secondo)
|Parole Chiave:||Catalysis; Heck reaction; Indole derivatives; Metallacycles; Palladium; Platinum|
|Settore Scientifico Disciplinare:||Settore CHIM/03 - Chimica Generale e Inorganica|
|Data di pubblicazione:||2005|
|Digital Object Identifier (DOI):||10.1016/j.jorganchem.2004.11.042|
|Appare nelle tipologie:||01 - Articolo su periodico|