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)] an d we have studied the influence of the -NPh(2) substituent on the reac tivity of the corresponding enolate Li[Ph(2)PCH(sic)C((sic)O)NPh(2)] t oward 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 li gand (Ph(2)P)(2)CHC(O)NPh(2) [bis(diphenylphosphino)-N,N-diphenylaceta mide] (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 rev ealed a mu(2)-eta(3) tripod-like bonding for L(2) in this centrosymmet ric dimeric complex: each copper atom is P,O-chelated by one ligand an d P-bonded to the other ligand. An eight-membered Cu2P4C2 ring is thus formed with the functional diphosphine ligand. The dynamic behavior h as been studied in CHCl3 solution of mono- and binuclear copper(I) com plexes of L(1) and L(2), Reversible oxygen-metal dissociation occurs i n 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) = dime thylbenzylamine (dmba); (10) (C N) = 8-methylquinoline (8-mq)]. The mo lecular 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 th e monoclinic space group P2(1)/c with Z = 4 in a unit cell of dimensio ns a = 8.801(2) Angstrom, b = 31.483(6) Angstrom, c = 10.939(2) Angstr om, beta = 101.37(2)degrees. The structure has been solved from diffra ctometer data by Patterson and Fourier methods and refined by full-mat rix 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 d ependence of the reaction of Li[Ph(2)PCH(sic)C((sic)O)NPh(2)] with [Pt Cl2(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 s-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 heterodifunc tional phosphines.