5044-52-0Relevant articles and documents
A convenient access to: N -phosphonio-substituted NHC metal complexes [M = Ag(i), Rh(i), Pd(II)]
Benaissa, Idir,Taakili, Rachid,Lugan, No?l,Canac, Yves
, p. 12293 - 12305 (2017)
A series of NHC pre-ligands featuring a pendant phosphonium moiety attached to N′ position through a propyl linker was readily obtained upon quaternization of N-mesityl- and N-methyl-imidazole, or N-mesityl-imidazoline using (3-bromo-propyl)-triphenylphosphonium bromide. Reactions of the resulting dicationic salts with [PdCl(allyl)]2 in the presence of K2CO3 afforded the anticipated NHC-ligated Pd(ii) metal complexes in high yields. Further treatment of the latter complexes with tBuOK induced a deprotonation of the carbon atom adjacent to the phosphonium moiety and the formation of the corresponding C,C-chelating NHC-phosphonium ylide Pd(ii) complexes. Investigation of an alternative synthetic route involving a silver transmetallation reaction incidentally allowed isolation and full characterization of an unusual dimeric tetranuclear NHC Ag(i) complex of general formula [(NHC~P+)2(Ag4Br6)2-].