- Visible-light-enhanced ring opening of cycloalkanols enabled by br?nsted base-tethered acyloxy radical induced hydrogen atom transfer-electron transfer
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A metal-free ring opening/halogenation of cycloalkanols, which combines both PPO/TBAX oxidant system and blue LEDs irradiation, is presented. This method produces diverse γ, α, and even more remotely halogenated ketones in moderate to excellent yields under mild conditions. Interestingly, experimental and computational studies demonstrate the novel ring size-dependent concerted/stepwise (four-/five- to eight-membered rings) hydrogen atom transfer-electron transfer induced by Br?nsted base-tethered acyloxy radical, which indicates distinct advantages brought by the cyclic structure of diacyl peroxides.
- Zhao, Rong,Yao, Yuan,Zhu, Dan,Chang, Denghu,Liu, Yang,Shi, Lei
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supporting information
p. 1228 - 1231
(2018/02/23)
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- Regioselective Synthesis of Carbonyl-Containing Alkyl Chlorides via Silver-Catalyzed Ring-Opening Chlorination of Cycloalkanols
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A novel and regioselective approach to carbonyl-containing alkyl chlorides via silver-catalyzed ring-opening chlorination of cycloalkanols is reported. Concurrent C(sp3)-C(sp3) bond cleavage and C(sp3)-Cl bond formation efficiently occur with good yields under mild conditions, and the chlorinated products are readily transformed into other useful synthetic intermediates and drugs. The reaction features complete regioselectivity, high efficiency, and excellent practicality. (Chemical Equation Presented).
- Huang, Feng-Qing,Xie, Jian,Sun, Jian-Guo,Wang, Yue-Wei,Dong, Xin,Qi, Lian-Wen,Zhang, Bo
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p. 684 - 687
(2016/03/01)
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- Catalytic asymmetric intramolecular homologation of ketones with α-diazoesters: Synthesis of cyclic α-Aryl/Alkyl β-ketoesters
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A catalytic asymmetric intramolecular homologation of simple ketones with α-diazoesters was firstly accomplished with a chiral N,N′-dioxide-Sc(OTf)3 complex. This method provides an efficient access to chiral cyclic α-aryl/alkyl β-ketoesters containing an all-carbon quaternary stereocenter. Under mild conditions, a variety of aryl- and alkyl-substituted ketone groups reacted with α-diazoester groups smoothly through an intramolecular addition/rearrangement process, producing the β-ketoesters in high yield and enantiomeric excess.
- Li, Wei,Tan, Fei,Hao, Xiaoyu,Wang, Gang,Tang, Yu,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
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p. 1608 - 1611
(2015/01/30)
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- Simplified heterocyclic analogues of fluoxetine inhibit inducible nitric oxide production in lipopolysaccharide-induced BV2 cells
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A series of fluoxetine, where the N-methylamino group was replaced and then simplified, were synthesized and their inhibitory effect was tested for nitric oxide (NO) production and inducible NO synthase (iNOS) expression in lipopolysaccharide (LPS)-induced BV2 cells. Although the synthesized compounds generally revealed weaker activity or greater cytotoxicity than fluoxetine, compound 10a, in which the N-methylamino group in fluoxetine was replaced by morpholine, and the trifluoromethylphenyl ring was substituted with simple oxo group, suppressed NO production dose-dependently at 10, 20 and 40 μM concentrations with less cytotoxicity than fluoxetine, and inhibited iNOS mRNA and protein expression at the same concentrations in LPS-induced BV2 cells. The results suggested that the trifluoromethylphenyl ring moiety in fluoxetine is not necessary for the suppression of NO production and that 10a has the potential as a potent inhibitor of NO production.
- Park, Ju-Young,Kim, Seung-Woo,Lee, Ja-Kyeong,Im, Weon Bin,Jin, Byung Kwan,Yoon, Sung-Hwa
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experimental part
p. 538 - 544
(2012/02/15)
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- D2 ANTAGONISTS, METHODS OF SYNTHESIS AND METHODS OF USE
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Provided are D2 or D3 antagonist compounds and pharmaceutical compositions of formula I and pharmaceutically acceptable salts thereof, or isomers thereof, wherein R1, R2 and R3 are as defined herein. The invention further comprises methods for making the compounds of the invention and methods for the treatment of conditions mediated by the dopamine D2 or D3 receptor from the compounds of the invention.
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Page/Page column 104
(2012/01/06)
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- Synthesis of γ-halogenated ketones via the Ce(IV)-mediated oxidative coupling of cyclobutanols and inorganic halides
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A straightforward method for the synthesis of γ-halo-substituted ketones formed via the CAN-initiated oxidative addition of halides to 1-substituted cyclobutanols has been developed. This method has short reaction times, and provides access to a range of bromo and iodo γ-substituted ketones in good to excellent yields.
- Casey, Brian M.,Eakin, Cynthia A.,Flowers II, Robert A.
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body text
p. 1264 - 1266
(2009/09/05)
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- 5-phenoxyalkoxypsoralens and methods for selective inhibition of the voltage gated Kv1.3 potassium channel
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Compositions of matter comprising 5-phenoxyalkoxypsoralen compounds and their method of synthesis and use. The compounds are useable to treat diseases or disorders in human or animal subjects, including autoimmune diseases. The compounds inhibit potassium
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Page/Page column 31
(2008/06/13)
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- Cross-Couplings of Unactivated Secondary Alkyl Halides: Room-Temperature Nickel-Catalyzed Negishi Reactions of Alkyl Bromides and Iodides
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The development of a nickel- or palladium-catalyzed method for cross-coupling unactivated secondary alkyl halides has been a long-standing challenge in synthetic chemistry. This communication describes a simple catalyst system-Ni(cod)2/s-Bu-Pybox-that achieves room-temperature Negishi reactions of an array of functionalized primary and secondary alkyl bromides and iodides. Copyright
- Zhou, Jianrong,Fu, Gregory C.
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p. 14726 - 14727
(2007/10/03)
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- Azetidinone derivatives for the treatment of atherosclerosis
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PCT No. PCT/EP95/04202 Sec. 371 Date Sep. 30, 1997 Sec. 102(e) Date Sep. 30, 1997 PCT Filed Oct. 25, 1995 PCT Pub. No. WO96/13484 PCT Pub. Date May 9, 1996Azetidinone derivatives of formula (I) in which R1 and R2, which may be the same or different, is each selected from hydrogen or C(1-8)alkyl; R3 is C(1-8)alkyl or C(3-8)cycloalkyl each of which may be optionally substituted; X is a linker group; Y is an aryl group; and n is 0, 1 or 2; and excluding benzyl (4-methylthio-2-oxo-azetidin-1-yl)acetate are inhibitors of the enzyme Lp PLA2 and are of use in therapy, in particular treating atherosclerosis.
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- Binding of spiperone analogs at 5-HT(2A) serotonin receptors
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Although spiperone displays good selectivity for 5-HT(2A) versus 5- HT(2C) serotonin receptors, it suffers from high affinity for 5-HT(1A) and dopamine D2 receptors. In order to determine a) the contribution of various structural features to 5-HT(2A) affinity, and b) if spiperone binds in a manner comparable to that of the 5-HT2 antagonist ketanserin, several abbreviated analogs of spiperone were prepared and examined. Removal of the spiperone fluoro group enhances 5-HT(2A) affinity several-fold, but does not improve its selectivity. The butyrophenone carbonyl group is not a major contributor to binding, but removal of the triazaspirodecanone carbonyl group reduces affinity at all receptor populations by about 100-fold. For a series of spiperone analogs, a three- to four-atom chain seems optimal for 5-HT(2A) affinity. On the basis of the structure-activity findings, it is concluded that ketanserin and spiperone likely bind at 5-HT(2A) receptors in a dissimilar manner.
- Khorana, Nantaka,Bondarev, Mikhail,Dukat, Malgorzata,Herrick-Davis, Katharine,Egan, Christina,DuPre, Ann,Smith, Carol,Teitler, Milt,Glennon, Richard A.
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p. 657 - 667
(2007/10/03)
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- Photochemistry of nonconjugated diketones: internal self-quenching and energy transfer
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The triplet state behavior of nine α,ο-dibenzoylalkanes indicates the occurrence of a rapid quenching interaction between the two carbonyl groups.This quenching is fastest (k=3E7 s-1) in dibenzoylbutane, is slightly slower (ca.E7 s-1) in dibenzoylethane, dibenzoylpentane, and 2,2-dibenzoylpropane, but is absent in 1,3-dibenzoylpropane.It also occurs in several "mixed" 1,4-diaroylbutanes incorporating p-ethylbenzoyl or p-methoxybenzoyl chromophores.This internal self-quenching is interpreted as the intramolecular counterpart of the well-know bimolecular self-quenching of aryl ketones, although no exact mechanism can be proposed.Such internal quenching does not occur as rapidly, if at all, in three "turned around" diketones: δ-(p-acetylphenyl)valerophenone, δ-(p-acetylphenoxy)valerophenone, and γ-(p-acetylphenoxy)butyrophenone.This fact, together with the varying rates of internal self-quenching in the dibenzoylalkanes, indicates the necessity for a very specific and close orientation of the two carbonyl groups for self-quenching.In the mixed diketones containing a p-alkylbenzoyl group, triplet excitation appears to be fully equilibrated between the two chromophores.However, in those containing a p-methoxybenzoyl group, excitation does not fully equilibrate before triplet decay, as evidenced by different quenching efficiencies for products from the two carbonyls.Analysis indicates intramolecular energy transfer rate constants -1.These are sufficiently lower than in other bichromophoric systems to suggest relatively slow energy hopping in the polymers of phenyl vinyl ketone.Key words: nonconjugated diketones, dibenzoylalkanes, sefl-quenching, energy transfer, triplet ketones.
- Wagner, Peter J.,Frerking, Harlan W. Jr.
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p. 2047 - 2061
(2007/10/03)
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- Structure-activity relationships within a series of analogues of the histamine H1-antagonist terfenadine
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A number of terfenadine derivatives including terfenadine enantiomers were synthesized and tested for histamine H1-receptor affinity. No significant differences in H1 activity were found between terfenadine enantiomers. Qualitative structure-activity relationship studies identified the α,α-diphenyl-4-piperidinomethanol moiety as the pharmacophore for the H1 activity of this group of compounds. The major role of the phenylbutanol moiety in terfenadine seems to be preventing the compound from crossing the blood-brain barrier.
- Zhang,Ter Laak,Timmerman
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p. 165 - 173
(2007/10/02)
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- Intramolecular Electron Transfer and SN2 Reactions in the Radical Anions of 1-Benzoyl-ω-haloalkane Studied by Pulse Radiolysis
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A one-electron reduction of 1-benzoyl-ω-haloalkane (Cl, Br, I) by solvated electrons and a subsequent intramolecular reaction of the radical anions, thus formed, have been investigated by using a pulse radiolysis technique.The reaction mechanism, electron transfer (ET) or SN2, and the rate constants were found to change as a function of the nature of the halide and the methylene chain length of the substrate.Although the order of reactivity based on leaving halogen atoms was I, Br, and Cl, the ease of the SN2 reaction was found to be in the order Cl>Br>I.In addition, the reaction rates were also affected by the polarity of the solvent used.On the basis of these results, it is discussed how the ET-SN%2 dichotomy takes place.
- Kimura, Norio,Takamuku, Setsuo
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p. 2433 - 2437
(2007/10/02)
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- Diphosphorus Tetraiodide. A Valuable Reagent in Cyclopropane Chemistry
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The behaviour of P2I4 and PI3 towards cyclopropyl alcohols, cyclopropyl ketones, α-seleno ketones, and ozonides is reported.
- Denis, J. N.,Krief, Alain
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p. 229 - 230
(2007/10/02)
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