- Diradicals Photogeneration from Chloroaryl-Substituted Carboxylic Acids
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With the aim of generating new, thermally inaccessible diradicals, potentially able to induce a double-strand DNA cleavage, the photochemistry of a set of chloroaryl-substituted carboxylic acids in polar media was investigated. The photoheterolytic cleavage of the Ar?Cl bond occurred in each case to form the corresponding triplet phenyl cations. Under basic conditions, the photorelease of the chloride anion was accompanied by an intramolecular electron-transfer from the carboxylate group to the aromatic radical cationic site to give a diradical species. This latter intermediate could then undergo CO2 loss in a structure-dependent fashion, according to the stability of the resulting diradical, or abstract a hydrogen atom from the medium. In aqueous environment at physiological pH (pH=7.3), both a phenyl cation and a diradical chemistry was observed. The mechanistic scenario and the role of the various intermediates (aryl cations and diradicals) involved in the process was supported by computational analysis.
- Di Terlizzi, Lorenzo,Protti, Stefano,Ravelli, Davide,Fagnoni, Maurizio
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- Pd(II)-catalyzed primary-C(sp3)-H acyloxylation at room temperature
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With the aid of a novel S-methyl-S-2-pyridyl-sulfoximine (MPyS) directing group (DG), the unactivated primary β-C(sp3)-H bond of MPyS-N-amides oxidizes at room temperature. The catalytic conditions are applicable to the diacetoxylation of primary β,β′-C(sp 3)-H bonds, and the carboxylic acid solvent is pivotal in the formation of the C-O bond. The MPyS-DG cleaves from the oxidation products and is recovered. This method provides convenient access to α,α′- disubstituted-β-hydroxycarboxylic acids.
- Rit, Raja K.,Yadav, M. Ramu,Sahoo, Akhila K.
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supporting information; experimental part
p. 3724 - 3727
(2012/08/28)
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- Highly regioselective carbonylation of unactivated C(sp3)-H bonds by ruthenium carbonyl
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The regioselective carbonylation of unactivated C(sp3)-H bonds of aliphatic amides was achieved using Ru3(CO)12 as a catalyst. The presence of a 2-pyridinylmethylamine moiety in the amide is crucial for a successful reaction. The reaction shows a preference for C-H bonds of methyl groups as opposed to methylene C-H bonds and tolerates a variety of functional groups. The stoichiometric reaction of an amide with Ru 3(CO)12 gave a dinuclear ruthenium complex in which the 2-pyridinylmethylamino moiety was coordinated to the ruthenium center in an N,N manner.
- Hasegawa, Nao,Charra, Valentine,Inoue, Satoshi,Fukumoto, Yoshiya,Chatani, Naoto
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p. 8070 - 8073
(2011/07/08)
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- Antagonists of the calcium receptor I. Amino alcohol-based parathyroid hormone secretagogues
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Functional screening of the former SmithKline Beecham compound collection against the human calcium receptor (CaR) resulted in the identification of the amino alcohol-based hit 2 (IC50 = 11 μM). Structure-activity studies of 2 focused on the optimization of the right- and left-hand side aromatic moieties as well as the amino alcohol linker region. Critical to the optimization of this antagonist template was the discovery that the chirality of the C-2 secondary alcohol played a key role in enhancing both CaR potency as well as selectivity over the β-adrenergic receptor subtypes. These SAR studies ultimately led to the identification of 38 (NPS 2143; SB-262470A), a potent and orally active CaR antagonist. Pharmacokinetic characterization of 38 in the rat revealed that this molecule had a large volume of distribution (11 L/kg), which resulted in a prolonged systemic exposure, protracted increases in the plasma levels of PTH, and an overall lack of net bone formation effect in a rodent model of osteoporosis.
- Marquis, Robert W.,Lago, Amparo M.,Callahan, James F.,Lee Trout, Robert E.,Gowen, Maxine,DelMar, Eric G.,Van Wagenen, Bradford C.,Logan, Sarah,Shimizu, Scott,Fox, John,Nemeth, Edward F.,Yang, Zheng,Roethke, Theresa,Smith, Brian R.,Ward, Keith W.,Lee, John,Keenan, Richard M.,Bhatnagar, Pradip
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scheme or table
p. 3982 - 3993
(2009/12/28)
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- CALCILYTIC COMPOUNDS
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Novel calcilytic compounds, pharmaceutical compositions, methods of synthesis and methods of using them are provided.
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- Method of using calcilytic compounds
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The present invention features calcilytic compounds. "Calcilytic compounds" refer to compounds able to inhibit calcium receptor activity. Also described are the use of calcilytic compounds to inhibit calcium receptor activity and/or achieve a beneficial effect in a patient; and techniques which can be used to obtain additional calcilytic compounds.
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- Effects of Certain Hallucinogenic Amphetamine Analogues on the Release of Serotonin from Rat Brain Synaptosomes
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The enantiomers of 3,4-(methylenedioxy)amphetamine (MDA), p-methoxyamphetamine (PMA), and N-Me-MDA (MDMA), along with their α,α-dimethylated derivatives, were evaluated for an effect on the release of serotonin from rat whole brain synaptosomes.The amphetamine isomers were all potent in inducing the release of serotonin at bath concentrations of 1 and 10 μM but were inactive at 0.1 μM.No significant difference in isomer potency was observed at the 10-μM concentration.However, at 1 μM the (+) isomer of MDMA was more effective in inducing release than was the (-) isomer.Since it is the (+) isomer which is clinically active, this result suggests that transmitter release may play a role in the biological activity of MDMA.By contrast, the α,α-dimethyl compounds were not effective in releasing serotonin, even at the highest bath concentration.
- Nichols, David E.,Lloyd, David H.,Hoffman, Andrew J.,Nichols, Maxine B.,Yim, George K. W.
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p. 530 - 535
(2007/10/02)
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