Chemoselective reactions of the phosphino enolate Li[Ph(2)PCH-C(-O)NPh(2)] with Ph(2)P-Cl and M-Cl bonds (M=Pd, Pt). Coordination properties of the new functional diphosphine ligand (Ph(2)P)(2)CHC(O)NPh(2). Hemilabile behavior of [Cu-2{(Ph(2)P)(2)CHC(O)NPh(2)-P,P,O}(2)](BF4)(2). Reactivity and molecular structure of [(8-mq)Pd{Ph(2)PCH-C(-O)NPh(2)}]

The functional phosphine Ph(2)PCH(2)C(O)NPh(2) (L(1)) was obtained by P-C selective coupling of Ph(2)PCl with Li[CH2(sic)C((sic)O)NPh(2)] and we have studied the influence of the -NPh(2) substituent on the reactivity of the corresponding enolate Li[Ph(2)PCH(sic)C((sic)O)NPh(2)] toward Ph(2)P-Cl and M-Cl bonds (M = Pd, Pt). A selective P-C coupling reaction with Ph(2)PCl allowed the synthesis of the new diphosphine ligand (Ph(2)P)(2)CHC(O)NPh(2) [bis(diphenylphosphino)-N,N-diphenylacetamide] (L(2)). The dicationic dinuclear complex [Cu-2{(Ph(2)P)(2)CHC(O)NPh(2)-P,P,O}(2)](BF4)(2) (3) has been obtained from the reaction of [Cu(NCMe)(4)](BF4) with L(2). A preliminary X-ray diffraction study revealed a mu(2)-eta(3) tripod-like bonding for L(2) in this centrosymmetric dimeric complex: each copper atom is P,O-chelated by one ligand and P-bonded to the other ligand. An eight-membered Cu2P4C2 ring is thus formed with the functional diphosphine ligand. The dynamic behavior has been studied in CHCl3 solution of mono- and binuclear copper(I) complexes of L(1) and L(2), Reversible oxygen-metal dissociation occurs in the presence of donor solvents such as NCMe or SMe(2). The reaction of Li[Ph(2)PCH(sic)C((sic)O)NPh(2)] with [(C N)Pd(mu-Cl)(2)] afforded the complexes [(C N)Pd{Ph(2)PCH(sic)C((sic)O)NPh(2)}] (9) (C N) = dimethylbenzylamine (dmba); (10) (C N) = 8-methylquinoline (8-mq)]. The molecular structure of [(8-mq)Pd{Ph(2)PCH(sic)C((sic)O)NPh(2)}] has been determined by single-crystal X-ray diffraction: it crystallizes in the monoclinic space group P2(1)/c with Z = 4 in a unit cell of dimensions a = 8.801(2) Angstrom, b = 31.483(6) Angstrom, c = 10.939(2) Angstrom, beta = 101.37(2)degrees. The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares methods on the basis of 2863 observed reflections to R and R(w) values of 0.0268 and 0.0338, respectively. A temperature dependence of the reaction of Li[Ph(2)PCH(sic)C((sic)O)NPh(2)] with [PtCl2(NCPh)(2)] has been observed which leads to cis-Pt[Ph(2)PCH(sic)C((sic) O)NPh(2)](2) (11) at -60 degrees C and to trans-Pt[Ph(2)PC{=C(NH)Ph}{C(O)NPh(2)}](2) (12) at 0 degrees C. The high reactivity of cis-Pt[Ph(2)PCH(sic)C)((sic)O)NPh(2)](2) toward p-MeC(6)H(4)NCO leads to two diastereoisomeric products cis-Pt[Ph(2)PCH{C(O)N(p-MeC(6)H(4))}{C(O)NPh(2)}](2) (16a,b in a 1:1 ratio), which contain new chiral heterodifunctional phosphines.