- Photoinduced substitution reaction in halothiophenes. Quantum-mechanical and photochemical studies on nitro- and cyano-derivatives
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2-Iodo-5-nitrothiophene, 2,-bromo-5-cyanothiophene, 2-iodo-5-cyanothiophene, and 4-iodo nitrobenzene were studied by steady state and pulsed methods and by semi-empirical quantum-mechanical computations. The quantum yields for the direct and sensitized photoarylation of these haloromatics following the photocleavage of the carbon-halogen bond were measured in benzene. The transient species originated by direct and sensitized laser excitation were examined by nanosecond laser flash photolysis in benzene and methylcyclohexane. The transients were characterized in terms of absorption spectra and decay lifetimes, and the triplet states were also characterized by phosphorescence measurements in rigid matrices at low temperature. The quenching rate constants of the triplet states and the quantum yields for singlet oxygen production were determined in methylcyclohexane. Findings obtained with sensitizers of various triplet energy showed that an upper triplet state is involved in the photocleaveage of the carbon-halogen bond.
- Aloisi,D'Auria,Latterini,Elisei
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- UREA DERIVATIVES AS CB1 ALLOSTERIC MODULATORS
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Heteroaryl and aliphatic analogs of diarylurea-based cannabinoid 1 receptor (CB1 R) allosteric modulators of formula (I) are described. Exemplary analogs can provide improved potencies and pharmacokinetic properties. Methods of using the analogs to treat
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Page/Page column 61; 62
(2021/01/23)
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- Synthesis of 2-Nitrothiophenes via Tandem Henry Reaction and Nucleophilic Substitution on Sulfur from β-Thiocyanatopropenals
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A new synthetic route of 2-nitrothiophenes was described through a tetra-n-butylammonium fluoride-promoted or diisopropylethylamine-promoted tandem Henry reaction and nucleophilic substitution of nitromethane with 3-thiocyanatopropenals, which were conveniently prepared by the replacement reaction of 3-chloropropenals with potassium thiocyanate under a mild acidic condition.
- Rong, Lin,Shen, Yingxia,Xiong, Guoxi,Gong, Yuefa
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p. 670 - 675
(2019/01/08)
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- A useful one-pot procedure for obtaining 2-aryl-5-nitrothiophenes from bromonitromethane and 3-aryl-3-chloro-propenals
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A one-pot procedure was developed to prepare new 2-aryl-5-nitrothiophenes efficiently from bromonitromethane and 3-chloro-3-aryl-propenals. Nitrothiophenes were synthesized in good yields with a simple and easy workup procedure. Georg Thieme Verlag Stuttg
- Rodríguez-Domínguez, Juan C.,Thomae, David,Seck, Pierre,Kirsch, Gilbert
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p. 286 - 288
(2008/12/20)
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- PHOTOCHEMICAL ARYLATION OF 2-IODO-5-NITROTHIOPHENE
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The arylation of 2-iodo-5-nitrothiophene by a photochemical process has been investigated.This compound, in contrast with the photochemical behaviour of 5-iodothiophene-2-carbonitrile, gives the corresponding aryl and heteroaryl derivatives in good yields on irradiation in the presence of various aromatic substrates (benzene, naphthalene, thiophene).The photochemical reaction of 2-iodo-5-nitrothiophene in the presence of phenylacetylene gives the corresponding substitution product on the alkyne.
- D'Auria, Maurizio
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p. 195 - 198
(2007/10/02)
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- SYNTHESIS AND PHOTOCHEMICAL PROPERTIES OF NITROTHIENYL DERIVATIVES
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Some 2-nitrothienyl derivatives characterized by the presence of an aryl or heteroaryl substituent in the C-5 position were synthesized by using a photochemical coupling procedure.All synthesized compounds were demonstrated to be singlet oxygen sensitizers in the trans-α,α'-dimethylstilbene photooxidation.
- D'Auria, Maurizio,Mauriello, Giacomo
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p. 542 - 545
(2007/10/02)
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