41583-00-0Relevant academic research and scientific papers
The asymmetric synthesis of phosphorus- and sulfur-containing tricarbonyl(η6-arene)chromium complexes using the chiral base approach
Ariffin, Azhar,Blake, Alexander J.,Ewin, Richard A.,Li, Wan-Sheung,Simpkins, Nigel S.
, p. 3177 - 3189 (2007/10/03)
The use of a simple chiral lithium amide base 2 enables the asymmetric transformation of tricarbonyl-[η6-(diphenylphosphinoyl)benzene]chromium(0) 12 into the corresponding ortho-silylated complex in up to 86% ee. A tin derivative was prepared similarly and was then used to prepare other derivatives via reduction to the corresponding phosphine, followed by transmetallation-electrophilic quench. In the case of tricarbonyl-(η6-1,3-dihydroisobenzothiophene)chromium(0) the chiral base 2 was ineffective, and it was necessary to use a bis-lithium amide base 9 to effect asymmetric substitution in high ee (up to 95%). Decomplexation gave the corresponding chiral sulfides in highly enantiomerically enriched form. In all cases the absolute stereochemistry of the products was derived by conducting X-ray structure determinations on selected examples. The Royal Society of Chemistry 1999.
Synthesis of some phosphino- and arsinobenzenechromium tricarbonyl derivatives and metal carbonyl clusters
Cullen, William R.,Rettig, Steven J.,Zhang, Hongli
, p. 2167 - 2181 (2007/10/03)
The synthesis of a number of new phosphino- and arsinobenzenechromium tricarbonyl ligands ER2C6H5Cr(CO)3 (ER2 = PEt2, PPri2;, PBut2, PPh2, AsPh2 AsMe2), ER[C6H5Cr(CO)3]2 (ER = PEt, PBut, PPh, AsPh) has been achieved by reacting lithium derivatives of benzenechromium tricarbonyl with appropriate chlorophosphines or iodoarsines. The spectroscopic properties of these ligands are described. The structure of Pri2PC6H5Cr(CO)3 was determined by an X-ray crystallographic study. This is the first solid state structure to be reported for a phosphinobenzenechromium tricarbonyl derivative. The structures of four metal carbonyl cluster complexes were also determined. Crystals of Pri2PC6H5Cr(CO)3 (3, C15H19CrO3P) are monoclinic, space group P21/c, a = 8.150(2) A, b = 13.490(2) A, c = 15.125(1) A, β = 100.19(1)°, Z = 4; those of Ru3(CO)11[PPri2C6H 5Cr(CO)3] (15, C26H19CrO14PRu3) are monoclinic, space group P21/n, a = 8.565(2) A, b = 21.808(3) A, c = 17.167(3) A, β = 97.41 (2)°, Z = 4; those of Ru3(CO)10[PPh2C6H 5Cr(CO)3]2 (19, C32H15CrO14PRu3) are orthorhombic, space group Pbca, a = 17.367(4) A, b = 24.471(5) A, c = 16.096(3) A, Z = 8; those of Ru3(CO)10[PPri2C6H 5Cr(CO)3]2·CH2Cl2 (16, C40H38Cr2O16P2Ru 3·CH2Cl2) are orthorhombic, space group P21212, a = 13.832(3) A, b = 17.558(2) A, c = 10.144(1) A, Z = 2; and those of Os3(CO)9[PEt2C6H 5Cr(CO)3]3 (26, C48H45Cr3O18Os3P 3) are trigonal, space group P3, a = 15.7558(4) A, c = 12.662(1) A, Z = 2. The structures were solved by the Patterson method and were refined by full-matrix least-squares procedures to R = 0.031, 0.027, 0.029, 0.025, and 0.029 (Rw = 0.027, 0.024, 0.024, 0.023, and 0.025) for 2326, 4110, 3878, 3046, and 4093 reflections with I ≥ 3σ(7), respectively.
DIPHENYLBENCHROTRENYLPHOSPHINE - A NEW TWO-ELECTRON LIGAND IN CARBONYL-CONTAINING ?-AROMATIC CHROMIUM AND MANGANESE COMPLEXES AND IN CARBONYLS OF GROUP VIB METALS
Losilkina, V. I.,Estekhina, M. N.,Baranetskaya, N. K.,Setkina, V. N.
, p. 187 - 196 (2007/10/02)
Photochemical substitution of CO ligands in C6H6Cr(CO)3, C5H5Mn(CO)3 and M(CO)6 (M = Cr, Mo, W) for PPh2C6H5Cr(CO)3 ligands was used to synthesize novel complexes:C6H6Cr(CO)2PPh2C6H5Cr(CO)3, C5H5Mn(CO)2PPh2C6H5Cr(CO)3 and M(CO)5PPh2C6H5Cr(CO)3.The complexes obtained have been characterized by elemental analysis, IR, 1H, 13C, 31P NMR, and mass spectra.The protonation reaction and the hydrogen isotopic exchange of arenechromium carbonyl complexes in acid media have been studied.The 13C NMR spectra of M(CO)5PPh2C6H5Cr(CO)3 show that the nature of the central metal atom influences the chemical shifts of the carbon nuclei of the carbonyl groups, shielding these atoms, increasing in the series W Cr.
