A series of lithium and aluminum complexes bearing [OC(But)CHP(Ph2)=NBut]-ligand were synthesized and characterized. Reaction of ButC(O)CH2Br with Ph2PNHBut afforded [Ph2P(NHBut)CH2C(O)But]+Br-(1). Treatment of 1 with excess of NaH in THF generated ligand precursor Ph2P(CH2C(O)But)=NBut (2). Reaction of 2 with AlR3 (R = Me,Et) gave N,O-chelate aluminum complexes [R2Al{OC(But)CHP(Ph2)=NBut}] (3,R = Me; 4,R = Et). Lithiation of 2 with an equiv. of LiBun formed lithium complex [Li{OC(But)CHP(Ph2)=NBut}] (5). Reaction of the lithium complex with an equiv. of AlCl3 yielded [Cl2Al{OC(But) CHP(Ph2)=NBut}] (6). Complex 6 was also obtained by reaction of 3 with an equiv. of AlCl3. Compounds 2-6 were characterized by NMR spectroscopy,elemental analysis and single crystal X-ray diffraction techniques (for 2,3 and 6). Catalysis of complexes 3 and 4 as well as [Me2Al{1-{OC(Ph)CH}-3-R1-5-MeC3HN2}] (R1 = Me,But) toward the ring-opening polymerization of ε-caprolactone was investigated.
