Synthesis and further reactivity studies of some transition metal gallyl complexes

Reactions of the anionic gallium(I) heterocycle salt, [K(tmeda)][Ga(DAB)] (DAB = {N(Dip)C(H)}2; Dip = C6H3Pri2-2,6), with a series of groups 6–9 and 11 metal halide complexes have given rise to the metal gallyl complexes, [CpCr(IMes){Ga(DAB)}] (IMes = :C{(Mes)NC(H)}2; Mes = mesityl), [M(tmeda){Ga(DAB)}2] (M = Mn, Fe or Co) and [Cu(dppe){Ga(DAB)}] (dppe = 1,2-bis(diphenylphosphino)ethane). The majority of the complexes have been crystallographically characterized. The reactivity of the previously reported copper(I) gallyl complex, [(IPr)Cu{Ga(DAB)}] (IPr = :C{(Dip)NC(H)}2), towards a variety of unsaturated substrates has been explored. Three crystallographically characterized complexes have arisen from this phase of the study, viz. [(IPr)CuCCPh], [(IPr)Cu{Ga(DAB)}(CNBut)] and [(IPr)Cu{κ1-OC(O)C(CNHDip)(NHDip)}]. The results of these investigations show that the reactivity of [(IPr)Cu{Ga(DAB)}] is significantly different to that of related copper boryl complexes.

Graphical abstractA variety of groups 6–9 and 11 metal gallyl complexes have been prepared and structurally characterized (e.g. see picture). Further reactivity studies have shown that a copper(I) gallyl compound displays very different reactivity towards unsaturated substrates than do related copper(I) boryl species.Figure optionsDownload full-size imageDownload as PowerPoint slide