- Acidic ionic liquid-catalyzed homologation of the polyene chain in α,β-enals (polyenals)
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An efficient green-chemistry synthesis of conjugated polyenals from α,β-enals, orthoesters, and alkyl vinyl ethers promoted by acidic ionic liquid [emim][HSO4] is described. The ionic liquid can be reused at least three times without any decrease in product yields.
- Kryshtal, Galina V.,Zhdankina, Galina M.,Ignat'Ev, Nikolai V.,Schulte, Michael,Zlotin, Sergei G.
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experimental part
p. 173 - 178
(2011/02/27)
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- Phenylamide and pyridylamide beta-secretase inhibitors for the treatment of alzheimer's disease
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The present invention is directed to phenylamide and pyridylamide derivative compounds of which are inhibitors of the beta-secretase enzyme and that are useful in the treatment of diseases in which the beta-secretase enzyme is involved, such as Alzheimer's disease. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the treatment of such diseases in which the beta-secretase enzyme is involved.
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Page/Page column 25
(2008/06/13)
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- 2, 4, 6-SUBSTITUTED PYRIDYL DERIVATIVE COMPOUNDS USEFUL AS BETA-SECRETASE INHIBITORS FOR THE TREATMENT OF ALZHEIMER’S DISEASE
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The present invention is directed to 2, 4, 6-substituted pyridyl derivative compounds which are inhibitors of the beta-secretase enzyme and that are useful in the treatment of diseases in which the beta-secretase enzyme is involved, such as Alzheimer’s disease. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the treatment of such diseases in which the beta-secretase enzyme is involved.
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Page/Page column 59-60
(2010/02/14)
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- A chemoselective reduction of alkynes to (E)-alkenes
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The trans reduction of all types of alkynes to give (E)-olefins is achieved through a two-stage trans hydrosilylation and protodesilylation. Reaction of an alkyne and a silane with the ruthenium catalyst [Cp*Ru(MeCN)3]PF6 results in
- Trost, Barry M.,Ball, Zachary T.,Joege, Thomas
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p. 7922 - 7923
(2007/10/03)
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- Alkylation of Enol Ethers Obtained by Treatment of α,β-Unsaturated Acetals with Organopotassium Reagents: An Inverse Polarity Approach
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The reaction of α,β-unsaturated acetals 1-4 with sec-butyllithium (2 equiv.) in the presence of potassium tert-butoxide in tetrahydrofuran at -95 deg C gave, as a result of 1,4-elimination, α-metallated enol ethers.The latter react with alkyl halides and carbonyl compounds to afford substitution and addition products.In particular, for the reaction with the acetal 1 and D2O as the electrophile, the α-deuteriated enol ether 5 cyclizes to -2-(prop-1-enyl)-1,3-dioxane.
- Canepa, Carlo,Prandi, Cristina,Sacchi, Luca,Venturello, Paolo
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p. 1875 - 1878
(2007/10/02)
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- The Influence of Intramolecular Dynamics on Branching Ratios in Thermal Rearrangements
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1- and 2-phenylbicyclohex-2-enes-5-d undergo thermal rearrangement to give products, differing only in the location of the deuterium, in ratio of about 9:1, but with identical activation enthalphies.Similarly, opticallly active trans-2-methyl-1-(trans-2-phenylethenyl)cyclopropane is found to rearrange to enantiomeric methylphenylcyclopentenes that are formed in a 5.9:1 ratio but with virtually identicyl activation enthalphies.Barring repeated coincidence, these results do not seem to be explicable within the framework of statistical theories of unimolecular kinetics such as RRKM theory, transition state theory, and variational transition state theory.The possible influence of dynamic effects in these and other unimolecular reactions is discussed.
- Newmann-Evans, Richard H.,Simon, Reyna J.,Carpenter, B. K.
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p. 695 - 711
(2007/10/02)
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- ACETALS AS CHIRAL AUXILIARIES Part 4 Asymmetric synthesis of γ,δ-ethylenic aldehydes An approach to the California Red scale pheromone
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Alkenyl copper - BF3 reagents, associated with tributylphosphine, react stereoselectively with chiral α, β-ethylenic acetals.A precursor of the California Red scale pheromone has been prepared.
- Mangeney, P.,Alexakis, A.,Normant, J. F.
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p. 2363 - 2366
(2007/10/02)
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- ASYMMETRIC SIMMONS-SMITH REACTIONS USING HOMOCHIRAL PROTECTING GROUPS
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Asymmetric Simmons-Smith reactions of α,β-unsaturated acetals derived from chiral dialkyl tartrate or (2R,4R)-2,4-pentanediol are described.Treatment of the acetal with diethylzinc and methylene iodide gives a cyclopropane with high diastereoselectivity.The acetal group is readily transformed to the aldehyde or the ester group.In addition, the method is successfully applied to the enantioselective synthesis of 5,6-methanoleukotriene A4, a stable and selective inhibitor of leukotriene biosynthesis.
- Mori, Atsunori,Arai, Isao,Yamamoto, Hisashi,Nakai, Hisao,Arai, Yoshinobu
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p. 6447 - 6458
(2007/10/02)
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