109583-33-7Relevant articles and documents
OXIDATION OF UNSATURARED LINEAR AND CYCLIC HYDROCARBONS BY MOLECULAR OXYGEN CATALYZED BY COMPLEXES OF TRANSITION METALS
Dzehemileva, G. A.,Odinokov, V. N.,Dzhemilev, U. M.
, p. 131 - 136 (1987)
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Strong Lewis acids derived from molybdenum and tungsten nitrosyls containing the tri-2-pyridylmethane ligand. Dynamic NMR studies of their adducts with aldehydes, ketones, and esters
Faller,Ma, Yinong
, p. 1579 - 1586 (1991)
The doubly charged Lewis acid percursors [HC(py)3M(NO)2(CO)](SbF6)2 (M = Mo, W; HC(py)3 = tri-2-pyridylmethane) are conveniently synthesized by reaction of HC(py)3M(CO)3 and 2 equiv of NOSbF6. Facile loss of CO from the precursors generates the [HC(py)3M(NO)2](SbF6)2 Lewis acids. The Lewis acidity of the tungsten complex is greater than that of the molybdenum complex. With the 1H NMR chemical shifts of bound crotonaldehyde as a qualitative assessment of relative acidity, the acidity of the tungsten species is comparable to that of BF3 and AlCl3, while that of the molybdenum species is similar to that of TiCl4. Analysis of the NMR spectra of the Lewis acid-organic carbonyl base adducts, which include the adducts of aldehydes, ketones, and esters, showed that η1-M(O=C) interactions dominate the chemistry. The barriers of rotation about the aldehyde C1-C2 bonds in the p-anisaldehyde adducts of the molybdenum and tungsten species were measured to be 12.8 and 13.7 kcal/mol, respectively, which are significantly higher than that for the free p-anisaldehyde. The exchange behavior between the E and Z isomers of the acetate adducts could be observed on the NMR time scale. The E to Z interconversion barriers of 12.2 ± 0.1 and 12.3 ± 0.1 kcal/mol for the methyl acetate and ethyl acetate complexes, respectively, were calculated from the results of variable-temperature proton NMR experiments. The free energy differences between the E and Z conformers of the methyl acetate and ethyl acetate adducts are 1.27 ± 0.01 and 0.96 ± 0.01 kcal/mol at 229 K, respectively.
Stoichiometric and catalytic cross dimerization between conjugated dienes and conjugated carbonyls by a ruthenium(0) complex: Straightforward access to unsaturated carbonyl compounds by an oxidative coupling mechanism
Hirano, Masafumi,Arai, Yasutomo,Hamamura, Yuka,Komine, Nobuyuki,Komiya, Sanshiro
experimental part, p. 4006 - 4019 (2012/07/13)
A series of stoichiometric and catalytic cross dimerizations between conjugated dienes and conjugated carbonyls are studied. The reaction of Ru(η4-cisoid-1,3-butadiene)(η4-1,5-COD)(NCMe) (2a) with methyl acrylate gives a Ru(0) complex, Ru[methyl η4-cisoid- (2E,4E)-hepta-2,4-dienoate](η4-1,5-COD)(NCMe) (3aa) in 97% yield. Similar treatments of 2a with a series of tert-butyl acrylate, methyl crotonate, 3-buten-2-one, and N,N-dimethylacrylamide produce similar analogues of 3ac. When (E)-1,3-pentadiene complex 2d is employed in the reaction with methyl acrylate, the branched coupling product Ru[methyl η4- cisoid-(2E,4E)-4-methylhepta-2,4-dienoate](η4-1,5-COD)(NCMe) (3da-b) is dominantly obtained in 65% yield along with the linear product in 19% yield. In the case of the (E)-2,5-dimethylhexa-1,3-diene complex 2e, the corresponding branch product is exclusively obtained in 86% yield. The catalytic cross dimerizations between conjugated dienes and conjugated carbonyls are established by 2. The origin of the present chemoselectivity is the η4-coordination of a conjugated diene and η2- coordination of an electron-deficient alkene to formal 6e coordination sites at Ru(0), and the regioselectivity being prone to giving branched products is interpreted as an oxidative coupling mechanism, involving nucleophilic attack of the coordinated diene to the coordinated electron-deficient alkene.
Na+-dependent high affinity binding of [3H]LY515300, a 3,4-dimethyl-4-(3-hydroxyphenyl)piperidine opioid receptor inverse agonist
Statnick, Michael A.,Suter, Todd M.,Gackenheimer, Susan L.,Emmerson, Paul J.,Quimby, Steve J.,Gehlert, Donald R.,Wheeler, William J.,Mitch, Charles H.
, p. 139 - 150 (2007/10/03)
Analogues of 3,4-dimethyl-4-(3-hydroxyphenyl)piperidines are high affinity inverse agonists for μ-, δ- and κ-opioid receptors. To characterize inverse agonist binding, we synthesized a high specific activity radioligand from this series, [3H]LY