Expanding the tools available for direct ortho cupration – targeting lithium phosphidocuprates

Abstract

Reaction of in situ generated lithium phosphides with 0.5 eq. Cu(I) is employed as a means of targeting lithium phosphidocuprates of either Gilman- or Lipshutz-type formulation – e.g., (R₂P)₂CuLi·n(LiX) (n = 0, 1). For R = Ph, X = CN in toluene followed by thf or R = Ph, X = I in thf/toluene an unexpected product results. [(Ph₂P)₆Cu₄][Li·4thf]₂1 reveals an ion-separated structure in the solid state, with solvated lithium cations countering the charge on an adamantyl dianion [(Ph₂P)₆Cu₄]²⁻. Deployment of R = Ph, X = CN in thf affords a novel network based on the dimer of Ph₂PCu(CN)Li·2thf 2 with trianions based on 6-membered (PCu)₃ rings acting as nodes in the supramolecular array and solvated alkali metal counter-ions completing the linkers. Cy₂PLi (Cy = cyclohexyl) has been reacted with CuCN in thf/toluene to yield Gilman-type lithium bis(phosphido)cuprate (Cy₂P)₂CuLi·2thf 3 by the exclusion of in situ generated LiCN. A polymer is noted in the solid state.