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A new palladium(I1) complex containing an amido-substituted P-chiral phosphine ligand is prepared efficiently by the asymmetric Diels-Alder reaction between N,N-dimethylacrylamide and l-phenyl-3,4-dimethylphosphole; the chelating properties of the functionalised ligand and the absolute configurations of the four newly generated stereocentres are determined by single-crystal X-ray analysis, and the optically active phosphine ligand displaced from the palladium template with 1,2-bis(diphenylphosphino)ethane.

The organopalladium complex containing ortho-metalated (S)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary has been used successfully to promote the asymmetric [4+2] Diels-Alder reactions between 1-phenyl-3,4-dimethylphosphole and the following coordinated dienophiles: (a) diphenylvinylphosphine; (b) (E)-diphenyl-1-propenylphosphine; (c) (Z)-diphenyl-1-propenylphosphine. Reaction a generates three carbon and one phosphorus stereogenic centers while reactions b and c each produce four carbon and one phosphorus chiral centers. In dichloromethane, all three reactions proceeded smoothly at room temperature giving the corresponding rigid diphosphines in high yields. Under similar reaction conditions, the reaction times observed for reactions a-c are 2, 3, and 50 h, respectively. Two-dimensional ROESY NMR studies confirmed that the prolonged reaction time required for reaction c is due to several major repulsive interactions between the chiral naphthylamine auxiliary and the (Z)-methyl-substituted vinylphosphine in the transition state. Nevertheless, all three reactions gave the corresponding rigid diphosphine in high yields. The absolute stereochemistries of the three bidentate phosphine ligands that were produced from the cycloaddition reactions have been assigned by 2D ROESY NMR spectroscopy. These diphosphines are powerful sequesterers of group 8 metals although they are highly air-sensitive in the free ligand form. The coordination chemistry and the absolute stereochemistry of the optically active complex [1alpha,4alpha,5alpha(S),6alpha(S),7R]-dichloro[5-(diphenylphosphino)-2,3,6-trimethy-7-phenyl-7-phosphabicyclo[2.2.1]-hept-2-ene-P(5)(),P(7)()]palladium(II) has been studied by single-crystal X-ray analysis. Crystal structure data: C(27)H(28)Cl(2)P(2)Pd, M(r) = 591.7; triclinic; space group P1; a = 8.643(3), b = 9.044(6), c = 9.058(4) Å; alpha = 102.75(4) degrees, beta = 108.59(2) degrees, gamma = 97.82(3) degrees; V = 638.0(5) Å(3); Z = 1; R(1) = 0.036.

The reaction of the ligand diphenyl(2-pyridy1)phosphine (L) with HAuCI, and AgCl affords the complexes [AuCIL] and [Ag2C12L3] respectively. The crystal structures of these two complexes have been determined from fourcircle diffractometer data; [AuCIL] is orthorhombic, space group Pnma, with a = 11.774(3), b = 12.61 7(3), and 11 .114(6) A, Z = 4, and R = 0.052 for 1 358 observed reflections; [Ag,CI,L,] is monoclinic, space group P2,/c with a = 14.599(3), b = 18.388(5), and c = 21.134(4) A, @ = 125.12(1)", Z = 4, and R = 0.060 for 5 180 observed reflections. In the gold complex the phosphorus of L alone is bonded to the gold atom which assumes a linear geometry with AU-CI 2.286(4) A and Au-P 2.234(4) A. The silver complex contains molecules in which two silver atoms are held together by two chloride bridges. One of the silver atoms is bonded to two L molecules through the phosphorus atom, while the other silver atom is bonded to a L molecule as well as loosely bonded to the nitrogen atom of one of the ligands co-ordinated to the first silver atom. The silver atoms assume a tetrahedral co-ordination with Ag-CI 2.701 (4), 2.618(8), 2.638(4), and 2.601 (9) A ; Ag-P 2.432(3), 2.436(4), and 2.452(3) A; and Ag-N 2.451 (9) 8.