36386-10-4Relevant academic research and scientific papers
Direct use of chiral or achiral organophosphorus boranes as pro-ligands for transition metal catalyzed reactions
Darcel, Christophe,Kaloun, El Bachir,Merdès, Rachid,Moulin, Dominique,Riegel, Nadège,Thorimbert, Serge,Genêt, Jean Pierre,Jugé, Sylvain
, p. 333 - 343 (2007/10/03)
Chiral or achiral organophosphorus borane complexes were used without isolation of the free tricoordinate P(III) ligand; thus, the borane adducts could be used either directly with metal salts to perform the catalysis, or they could be decomplexed by DABCO, or cyclooctadiene, and used in situ to generate the catalytic species. Chiral copper, palladium and rhodium complexes prepared using this method, were tested in asymmetric organometallic catalyzed 1,4-addition to 2-cyclohexenone, allylation of Schiff base and hydrogenation of α-acetamidocinnamic acid derivatives, respectively.
Solution equilibria of tertiary phosphine complexes of copper(I) halides
Fife, Dennis J.,Moore, William M.,Morse, Karen W.
, p. 1684 - 1691 (2008/10/08)
The solution equilibria in benzene of arylphosphine complexes of the type LmCunXn (L = Ph3P, MePh2P; X = Cl, Br, I; m:n = 3:1, 4:2, 3:2, 2:2, 4:4) have been investigated by using UV spectrometry and vapor pressure osmometry. The halogen appears to have only a minor effect on the dissociation. A detailed analysis of the chloride complexes shows that ligand dissociation of the L3CuCl complexes is also accompanied by dimerization of the coordinately unsaturated copper(I) complexes through halogen bridging. However, the dimeric and tetrameric species formed by halogen bridging are found to be significant species in solution only when the ratio of L to CuCl is less than 3:1. An equilibria system is proposed with equilibrium constants derived from the modeling of the experimental data. The constants for the single ligand dissociation from (Ph3P)3CuCl and (MePh2P)3CuCl are 2 × 10-2 and 2 × 10-4, respectively. With the much greater dissociation of the Ph3P complex, the (Ph3P)2CuCl species is the dominant form in a benzene solution made from the solid-state (Ph3P)3CuCl complex. Solution profiles of different ratios of L to CuCl are generated to show how various species present in solution vary with concentration. The stability of the LmCunCln complexes (Ph3P ? MePh2P) toward ligand dissociation is attributed to greater steric interactions of Ph3P in comparison to MePh2P.
Single hydrogen-boron bridged species: Tris(methyldiphenylphosphine) complexes of silver(I) and copper(I) containing tetrahydroborate and (ethoxycarbonyl)trihydroborate
Bommer, Jerry C.,Morse, Karen W.
, p. 587 - 593 (2008/10/08)
The complexes (tetrahydroborato)tris(methyldiphenylphosphine)copper(I), (tetrahydroborato)tris(methyldiphenylphosphine)silver(I), ((ethoxycarbonyl)trihydroborato)tris(methyldiphenylphosphine)copper(I), and ((ethoxycarbonyl)-(trihydroborato)tris(methyldiphenylpnosphine)silver(I) have been synthesized and characterized. IR data and analysis support the presence of a hydrogen singly bridged to the metal in the solid species. In solution, conductivity, molecular weight, and NMR data indicate the existence of equilibrium between singly and doubly bridged species. Factors influencing the formation of a singly bridged vs. a doubly bridged species are discussed.
