835923-07-4Relevant academic research and scientific papers
Formation of a chiral NPPN ligand via metallation of acyclic NPNCN systems
Chivers, Tristram,Copsey, May C.,Parvez, Masood
, p. 2818 - 2819 (2004)
A new type of bidentate N,N′-chelating ligand containing a chiral phosphorus centre has been synthesized via the metallation of an acyclic NPNCN species. The zwitterionic ligand backbone contains a phosphenium centre stabilised by an imido phosphine fragment.
Synthesis of acyclic NPNCN systems and metalation reactions with organolithium, -magnesium, and -aluminum reagents
Chivers, Tristram,Copsey, May C.,Fedorchuk, Chantall,Parvez, Masood,Stubbs, Michael
, p. 1919 - 1928 (2008/10/09)
The preparation of a new family of acyclic DippN(H)P(Ph)NRCR′NR systems (2a-c) has been achieved by the reaction of the mono(amino) chlorophosphine PhP(Cl)N(H)Dipp (1; Dipp = 2,6-(iPr) 2C6H3) with 1 equiv of Li[CR′(NR) 2] (2a, R = tBu, R′ = nBu; 2b, R = Cy, R′ = tBu; 2c, R = Cy, R′ = nBu). Metalation reactions of 2a-c using nBuLi, Me3Al, and Bu2Mg have shown that the NPNCN backbone is susceptible to nucleophilic attack. Reactions of 2a or 2b with nBuLi or Me3Al, respectively, produce the complexes Li[DippNPhP-P(nBu)PhNDipp]· Et 2 (3) and Al(Me)2[DippNPhP-P(Me)PhNDipp] (4). These complexes involve a new type of N,N′ bidentate ligand with a chiral phosphorus center bearing bulky organic substituents on the nitrogen atoms. Reaction of 2c with Bu2Mg proceeds in a different manner, producing the amidinate complex Mg[CyNC(nBu)NCy][DippNP(nBu)Ph] ·Et2O (5). A more direct route to 3 and the analogous methyl-substituted complex Li[DippNPhP-P(Me)PhNDipp]·Et2)O (6), involving the reaction of 1 with the appropriate organolithium reagent in the molar ratio 2:3, has been developed. The oxidation product of 3, {Li[DippNPhP(O)P(nBu)PhNDipp]}2 (7), has also been synthesized via an alternative route. Complexes 1, 2a,b, and 5-7 were fully characterized by multinuclear NMR spectroscopy, elemental analysis, and X-ray crystallography.
