92695-35-7Relevant academic research and scientific papers
Syntheses and structures of ?-pyridine, quinoline, and isoquinoline complexes of the formula 5-C5H5)Re(NO)(PPh3)(NCxHy)>+ CF3SO3-
Dewey, Michael A.,Arif, Atta M.,Gladysz, J. A.
, p. C29 - C32 (1990)
Reaction of (η5-C5H5)Re(NO)(PPh3)(OTf) with pyridine, quinoline, and isoquinoline gives the title complexes in high yields.The crystal structure of the isoquinoline complex is determined, and exhibits unexpected features.
Sulfur-coordinated thiophene and benzothiophene in Cp(NO)(PPh3)Re(thiophene)+: Conversion to thienyl and thienylcarbene complexes
Robertson, Mitchell J.,White, Carter J.,Angelici, Robert J.
, p. 5190 - 5195 (1994)
A series of stable sulfur-coordinated thiophene complexes Cp(NO)(PPh3)Re(η1(S)-Th)+, Cp = η5-C5H5, Th = thiophene (T), 2,5-Me2T, benzo[b]thiophene (BT), and 2-MeBT, are prepared by the reaction of Cp(NO)-(PPh3)Re(ClCH2Cl)+ with thiophenes. The T and BT complexes react with bases to abstract a proton from the 2-carbon of the η1(S)-coordinated thiophenes to give neutral 2-thienyl (2-Tyl) or 2-benzothienyl (2-BTyl) complexes. equation presented Reaction of the 2,5-Me2T complex with base results in proton abstraction at the 3-carbon to give the 3-(2,5-Me2Tyl) complex. The 2-Tyl and 2-BTyl complexes react with CF3SO3H to give cationic thienylcarbene and benzothienylcarbene complexes, respectively, which are isomers of the starting η1(S)-coordinated thiophene complexes. This series of facile reactions demonstrates that η1(S) coordination can activate thiophenes in a way that leads to the disruption of the aromaticity of the thiophene ligand upon formation of the thienylcarbene complexes. The base removal of the 2-proton from η1(S)-thiophene ligands also suggests a mechanism for the exchange of these protons with deuterium during the hydrodesulfurization of thiophenes on heterogeneous catalysts.
Synthesis and reactivity of chiral metal fluoride and water complexes derived from the rhenium fragment [(η5-C5H5)Re(NO) (PPh3)]+
Agbossou, Sénamé K.,Roger, Christophe,Igau, Alain,Gladysz
, p. 419 - 424 (2008/10/08)
Reactions of triflate complex (η5-C5H5)Re(NO)(PPh3)(OTf) (6), chlorobenzene complex [(η5-C5H5)Re(NO)(PPh3)-(ClC 6H5)]+BF4-, and tetrahydrofuran complex [(η5-C5H5)Re(NO)(PPh 3)(THF)]+BF4- with (Me2N)3S+[SiMe3F2] - give fluoride complex (η5-C5H5)Re(NO)(PPh3)(F) (3) in ≥95% NMR yields. Analytically pure 3 can be isolated from the last reaction in 65-75% yields, but decomposes on the time scale of hours in solution. The reaction of 3 with BF3·OEt2 (-95 to -40°C) gives the dichloromethane complex [(η5-C5H5)Re(NO)(PPh3)(ClCH 2Cl)]+BF4- (1), and that with MeOTf gives 6 and MeF. Reaction of 3 and P(p-tol)3 gives mainly the fluoride ligand substitution product [(η5-C5H5)Re(NO)(PPh 3)(P(p-tol)3)]+X-. Reaction of 1 and H2O gives the water complex [(η5-C5H5)Re(NO)(PPh3)(OH 2)]+BF4- (4+BF4-, 87%), which in turn reacts with CH3CN (3 equiv) to give [(η5-C5H5)Re(NO)(PPh3)(NCCH 3)]+BF4- and H2O. Reaction of (η5-C5H5)Re(NO)(PPh3)(H) with Ph3C+PF6- and then H2O gives 4+PF6- (91%). Reaction of (η5-C5H5)Re(NO)(PPh3)(CH 3) and aqueous HF appears to give water complex 4+X- (X- = F- or HF2-). Complex 3 is inert to water, but converts to 4+X- in the presence of HF or HBF4·OEt2.
Cleavage of the rhenium-methyl bond of (η-C5H5)Re(NO)(PPh3)(CH3) by protic and halogen electrophiles: Stereochemistry at rhenium
Merrifield, James H.,Fernández, Jesús M.,Buhro, William E.,Gladysz
, p. 4022 - 4029 (2008/10/08)
Reaction of (+)-(S)-(η-C5H5)Re(NO)(PPh3)(CH 3) ((+)-(S)-1) with HX gives (+)-(η-C5H5)Re(NO)(PPh3)(X) (X = Cl, (+)-(S)-2; X = Br, (+)-(R)-3; X = I, (+)-(R)-4; X = OSO2CF3, (+)-(R)-5; X = OCOCF3, (+)-(R)-6; X = OCHO, (+)-(R)-7; X = OSO2-p-C6H4CH3, (+)-(R)-8) in 63-85% yields and ≥99% retention of configuration at rhenium. The corresponding reactions of (±)-1 give (±)-2-(±)-8 (69-89%). Triflate (+)-(R)-5 and halides (+)-(S)-2 and (+)-(R)-3 are configurationally and chemically less stable than the other cleavage products. Reactions of (-)-(S)-CH3CH2CH(C6H5)CN with (+)-(R)-5, (+)-(S)-2/AgPF6, (+)-(R)-3/AgPF6, and (+)-(R)-4/AgPF6 give (+)-(SS)-[η-C5H5)Re(NO)(PPh3)-(NCCH(C 6H5)CH2CH3)]+X - ((+)-(SS)-9+X-) of ≥99% diastereomeric purity. Reaction of (+)-(R)-7 with (CH3)3SiCl gives HCO2Si(CH3)3 and (+)-(S)-2 in 98% ee. Reaction of (+)-(R)-5 with CO (2000 psi) gives (+)-(S)- [(η-C5H5)Re-(NO)(PPh3)(CO)] +CF3SO3- in 78% ee. Reaction of (+)-(S)-1 with Cl2, Br2, and I2 gives essentially racemic 2, 3, and 4, respectively. The mechanisms of these reactions, and absolute configuration assignments, are discussed. Products 2-8 are characterized by microanalysis and NMR, IR, mass, UV, ORD, and CD spectroscopy.
