- A convenient access to: N -phosphonio-substituted NHC metal complexes [M = Ag(i), Rh(i), Pd(II)]
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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-].
- Benaissa, Idir,Taakili, Rachid,Lugan, No?l,Canac, Yves
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- SYNTHESE DE SELS DE VINYLPHOSPHONIUMS β-SUBSTITUES ET DE SELS D'ALKYLPHOSPHONIUMS β-DISUBSTITUES
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Vinylene-1,2 bisphosphoniums salts react, in the presence of a base, with compounds ZH having a mobile hydrogen, to give a way of sysnhesis of β-substituted vinylphosphoniums salts 2 or β-disubstituted alkylphosphoniums salts 3.We have studied the limits of these synthesis depending on the experimental conditions and the nature of compounds ZH (alcohols, phenols, thiols, phosphines, amines).
- Cristau, Henri-Jean,Bottaro, Denis,Plenat, Francoise,Pietrasanta, Francine,Christol, Henri
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