- Polymer-bound chiroptical molecular switches; photochemical modification of the chirality of thin films
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Photobistable chiral polymers were obtained by covalent attachment of inherently dissymmetric 2-hydroxy-9-(7′methyl-1′,2′,3′,4′- tetrahydrophenanthrene-4′-ylidene)-9H-thioxanthene to methacrylate copolymers with appropriate spacers. Upon irradiation at 300 nm the optical activity of thin films of these polymers could be altered.
- Oosterling, Michiel L.C.M.,Schoevaars, Anne Marie,Haitjema, Henk J.,Feringa, Ben L.
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Read Online
- Rational design of triplet sensitizers for the transfer of excited state photochemistry from UV to visible
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Time Dependent Density Functional Theory has been used to assist the design and synthesis of a series thioxanthone triplet sensitizers. Calculated energies of the triplet excited state (ET) informed both the type and position of auxochromes placed on the thioxanthone core, enabling fine-tuning of the UV-vis absorptions and associated triplet energies. The calculated results were highly consistent with experimental observation in both the order of the λmax and ET values. The synthesized compounds were then evaluated for their efficacies as triplet sensitizers in a variety of UV and visible light preparative photochemical reactions. The results of this study exceeded expectations; in particular [2 + 2] cycloaddition chemistry that had previously been sensitized in the UV was found to undergo cycloaddition at 455 nm (blue) with a 2- to 9-fold increase in productivity (g/h) relative to input power. This study demonstrates the ability of powerful modern computational methods to aid in the design of successful and productive triplet sensitized photochemical reactions.
- Booker-Milburn, Kevin,Elliott, Luke D.,George, Michael W.,Kayal, Surajit
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supporting information
p. 14947 - 14956
(2020/10/13)
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- Transition-metal-free synthesis of unsymmetrical diaryl chalcogenides from arenes and diaryl dichalcogenides
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A transition-metal-free synthetic method has been developed for the synthesis of unsymmetrical diaryl chalcogenides (S, Se, and Te) from diaryl dichalcogenides and arenes under oxidative conditions by using potassium persulfate at room temperature. Variously substituted arenes such as anisole, thioanisole, diphenyl ether, phenol, naphthol, di- and trimethoxy benzenes, xylene, mesitylene, N,N-dimethylaniline, bromine-substituted arenes, naphthalene, and diaryl dichalcogenides underwent carbon-chalcogen bond-forming reaction to give unsymmetrical diaryl chalcogenides in trifluoroacetic acid. To understand the mechanistic part of the reaction, a detailed in situ characterization of the intermediates has been carried out by 77Se NMR spectroscopy by using diphenyl diselenide as the substrate. 77Se NMR study suggests that electrophilic species ArE+ is generated by the reaction of diaryl dichalcogenide with persulfate in trifluoroacetic acid. The electrophilic attack of arylchalcogenium ion on the arene may be responsible for the formation of the aryl-chalcogen bond.
- Prasad, Ch Durga,Balkrishna, Shah Jaimin,Kumar, Amit,Bhakuni, Bhagat Singh,Shrimali, Kaustubh,Biswas, Soumava,Kumar, Sangit
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p. 1434 - 1443
(2013/03/29)
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- THIOARYL SUBSTITUTED INHIBITORS OF ZINC PROTEASES AND THEIR USE
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There are described compounds having the general formula (I) below and their pharmaceutically acceptable salts thereof, wherein E, X, m, q, R1, R2, n and ZBG have the meanings reported in the description useful, in therapy, as inhibi
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Page/Page column 22
(2009/10/01)
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- Design, synthesis, biological evaluation, and NMR studies of a new series of arylsulfones as selective and potent matrix metalloproteinase-12 inhibitors
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Overexpression of macrophage elastase (MMP-12), a member of the matrix metalloproteinases family, can be linked to tissue remodeling and degradation in some inflammatory processes, such as chronic obstructive pulmonary disease (COPD), emphysema, rheumatoi
- Nuti, Elisa,Panelli, Laura,Casalini, Francesca,Avramova, Stanislava I.,Orlandini, Elisabetta,Santamaria, Salvatore,Nencetti, Susanna,Tuccinardi, Tiziano,Martinelli, Adriano,Cercignani, Giovanni,D'Amelio, Nicola,Maiocchi, Alessandro,Uggeri, Fulvio,Rossello, Armando
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experimental part
p. 6347 - 6361
(2010/03/24)
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- INHIBITORS OF ZINC PROTEASES THIOARYL SUBSTITUTED AND THEIR USE
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There are described compounds having the general formula (I) below and their pharmaceutically acceptable salts thereof, wherein E, X, m, q, R1, R2, n and ZBG have the meanings reported in the description useful, in therapy, as inhibi
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Page/Page column 51
(2008/06/13)
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- Regioselective copper-catalyzed C-N and C-S bond formation using amines, thiols and halobenzoic acids
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A regioselective method for highly efficient C-N and C-S bond formation with 2-halobenzoic acids is described. The Cu/Cu2O-catalyzed reaction is carried out in 2-ethoxyethanol or ethylene glycol diethyl ether and does not require the use of strong base or other additives. This procedure eliminates the need for acid protection, tolerates a wide range of functional groups and provides aromatic and aliphatic amines and sulfides in 81-99% yield. Georg Thieme Verlag Stuttgart.
- Liu, Shuanglong,Pestano, John Paul C.,Wolf, Christian
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p. 3519 - 3527
(2008/09/19)
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- Synthesis of s-pixyl derivatives for mass spectrometric applications
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Synthesis of novel S-pixyls based on the thioxanthyl skeleton is described. Thioxanthone derivatives were prepared by a regioselective intramolecular Friedel-Crafts acylation reaction and converted into S-pixyl derivatives by Grignard synthesis. S-Pixyl carbocations stabilised by electron donating groups on the thioxanthyl backbone produced exceptional mass spectra under (MA)LDI conditions (laser desorption ionisation, both with and without matrix), and can be detected down to femtomol levels. Georg Thieme Verlag Stuttgart.
- Khan, Safraz,Bernad, Pablo L.,Korshun, Vladimir A.,Southern, Edwin M.,Shchepinov, Mikhail S.
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p. 2453 - 2456
(2007/10/03)
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- POTENTIAL ANTIDEPRESSANTS: 2-(METHOXY- AND HYDROXY-PHENYLTHIO)BENZYLAMINES AS SELECTIVE INHIBITORS OF 5-HYDROXYTRYPTAMINE RE-UPTAKE IN THE BRAIN
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2-, 3- and 4-Methoxythiophenol, and 2,4-, 2,5- and 3,4-dimethoxythiophenol were transformed in two steps to the corresponding 2-(methoxyphenylthio)benzoyl chlorides XIII which were reacted with ammonia, methylamine, dimethylamine, diethylamine, dipropylamine, and di(2-propyl)amine to give the amides XIV-XIX.These were reduced mostly with lithium aluminium hydride to the amines II-VII.These methoxylated amines were demethylated mostly either by heating with pyridine hydrochloride or by treatment with boron tribromide.Some of the 2-(methoxy- and hydroxy-phenylthio)benzylamines prepared, especially compounds II, III, XXI, and XXII, indicated properties of potential antidepressants being highly active and selective inhibitors of 5-hydroxytryptamine re-uptake in the brain structures and having the typical antireserpine activity.The most interesting compound of the series is XXIb (hydrogen maleate VUFB-15 468) which is undergoing preclinical studies.On the basis of its structure, some further compounds (XXVII-XXIX, XXXIX-XLI) were prepared by various methods.
- Jilek, Jiri,Sindelar, Karel,Pomykacek, Josef,Kmonicek, Vojtech,Sedivy, Zdenek,et al.
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p. 3294 - 3338
(2007/10/02)
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- Studies in Rearrangement of 2-(Arylthio)benzohydroxamic Acids to the Corresponding 2-(Arylsulphinyl)benzamides
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2-(2'-Methoxyphenylthio)-(III)-, 2-(4'-methoxyphenylthio)-(IV)-, 2-(2'-methylphenylthio)-(V)- and 2-(4'-methylphenylthio)-(VI)-benzohydroxamic acids on treatment with polyphosphoric acid yield 2-(2'-methoxyphenylsulphinyl)-(VII)-, 2-(4'-methoxyphenylsulphinyl)-(VIII)-, 2-(2'-methylphenylsulphinyl)-(IX)- and 2-(4'-methylphenylsulphinyl)-(X)-benzamides respectively, illustrating the generality of rearrangement reported earlier .The rearrangement can also be effected with other reagents like xylene-P2O5, perchloric acid- gl. acetic acid and trifluoracetic acid. 2-Methylthiobenzohydroxamic acid (XI) and 4-(phenylthio)benzohydroxamic acid (XII) when treated with PPA yield benzothiazolone (XIII) and 4-aminodiphenyl sulphide (XIV).Experimental evidence has been presented which points to a concerted mechanism for the intramolecular oxygen transfer.
- Dhareshwar, G. P.,Chhaya, P. N.,Hosangadi, B. D.
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p. 831 - 835
(2007/10/02)
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