Structural Diversity of Lithium N ‐Mesityl‐ P , P ‐diphenylphosphinimidate of the type [(L)Li{O−PPh 2 =N−Mes] n Depending on Lewis Base L

Abstract Metalation of N ‐mesityl‐ P,P ‐diphenylphosphinic amide with n BuLi in toluene yields tetranuclear lithium N ‐mesityl‐ P , P ‐diphenylphosphinimidate ([Ph 2 P(OLi)=N−Mes] 4 , 1 ). Metalation of Ph 2 P(O)−N(H)Mes with a mixture of dibutylmagnesium and butyllithium in DME leads to formation of dinuclear [Ph 2 P{OLi(dme)}=N−Mes] 2 ( 2 ). Excess of Ph 2 P(O)−N(H)Mes gives dinuclear [Li(O−PPh 2 =N−Mes){Ph 2 P(=O)−N(H)−Mes}] 2 ( 3 ) with three‐coordinate alkali ions. The metathetical approach via reaction of 1 with anhydrous magnesium bromide in ethereal solution yields [{(thf)LiBr} 2 {(thf)Li(O−PPh 2 =NMes)(Et 2 O)Li(O−PPh 2 =NMes)}] ( 4 ). Heterobimetallic Li/Mg compounds are not accessible by these protocols. Reactions of 1 with DME, with excess of Ph 2 P(O)−N(H)Mes or with LiBr allows the straightforward conversion to compounds 2 , 3 and 4 .