Exploiting deprotonative co‐complexation to access potassium metal(ates) supported by a bulky silyl(bis)amide ligand

Bimetallic complexes combining an alkali‐metal with a lower electropositive metal have demonstrated unique chemical profiles which can be rationalised in terms of chemical cooperativity. Advancing the rational design of these types of complexes, a adaptable method is described to prepare a new family of potassium metal(ates) containing the highly sterically demanding silyl(bis)amide {Ph2Si(NAr*)2}2− (Ar*=2,6‐diisopropylphenyl). Using a sequential deprotonative co‐complexation approach, mono‐metallation of Ph2Si(NHAr*)2 (1) is accomplished using potassium alkyl KCH2SiMe3 yielding [{Ph2Si(NHAr*)(NAr*)K}∞] (2), which, in turn, undergoes co‐complexation with the relevant M(CH2SiMe3)2 (M=Mg, Zn, Mn) enabling metallation of the remaining NHAr* group to furnish silylbis(amido) alkyl potassium metal(ates) [{Ph2Si(NAr*)2M(THF)x(CH2SiMe3)}−{K(THF)y}+] (M=Zn, x=0, y=4, 3; M=Mg, x=1, y=3, 4; and M=Mn, x=0, y=4, 5). Reactivity studies of potassium manganate 5 with the amine HMDS(H) (HMDS=N[SiMe3]2 revealed the kinetic activation of the remaining alkyl group on Mn furnishing [K(THF)2{Ph2Si(NAr*)2}Mn(HMDS)] (6). The structures of these bimetallic complexes along with that of the potassium precursor 2 have been established by X‐ray crystallographic studies.