Synthesis of crown ether complexes of alkali-metallated organophosphine oxides and insertion reactions with isonitriles

The synthesis and crystal structures of the alkali-metallated organophosphine oxides [{Ph2P(O)CH2}K · 18-crown-6] (1) and [{Ph2P(O)CH2}Na · 15-crown-5] (2) are reported. In addition the insertion reaction of an isonitrile into the C–Li bond of [{Ph2P(O)CH2}Li] is reported and the crystal structure of the resulting tetrameric complex [Ph2P(O)CHdouble bond; length as m-dashCHN(Cy)Li]4 (3) (Cy = Cyclohexyl) described.