- Effect of a Pendant Acceptor on Thermally Activated Delayed Fluorescence Properties of Conjugated Polymers with Backbone-Donor/Pendant-Acceptor Architecture
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Three sets of conjugated polymers with backbone-donor/pendant-acceptor architectures, named PCzA3PyB, PCzAB2Py, and PCzAB3Py, are designed and synthesized. The three isomeric benzoylpyridine-based pendant acceptor groups are 6-benzoylpyridin-3-yl (3PyB), 4-((pyridin-2-yl)carbonyl)phenyl (B2Py) and 4-((pyridin-3-yl)carbonyl)phenyl (B3Py), whereas the identical backbone consists of 3,6-carbazolyl and 2,7-acridinyl rings. One acridine ring and each acceptor group constitute a definite thermally activated delayed fluorescence (TADF) unit, incorporated into the main chain of the polymers through the 2,7-position of the acridine ring with the varied content. All of the polymers display legible TADF features with a short microsecond-scale delayed lifetime (0.56–1.62 μs) and a small singlet/triplet energy gap (0.10–0.19 eV). Progressively redshifted emissions are observed in the order PCzAB3Py, PCzA3PyB, and PCzAB2Py owing to the different substitution patterns of the pyridyl group. Photoluminescence quantum yields can be improved by regulating the molar content of the TADF unit in the range 0.5–50 %. The non-doped organic light-emitting devices (OLEDs) fabricated by solution-processing technology emit yellow-green to orange light. The polymers with 5 mol % of the TADF unit exhibit excellent comprehensive electroluminescence performance, in which PCzAB2Py5 achieves a maximum external quantum efficiency (EQE) of 11.9 %, low turn-on voltage of 3.0 V, yellow emission with a wavelength of 573 nm and slow roll-off with EQE of 11.6 % at a luminance of 1000 cd m?2 and driving voltage of 5.5 V.
- Yang, Yike,Li, Kuofei,Wang, Chenxu,Zhan, Hongmei,Cheng, Yanxiang
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- Analogues of fenarimol are potent inhibitors of trypanosoma cruzi and are efficacious in a murine model of chagas disease
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We report the discovery of nontoxic fungicide fenarimol (1) as an inhibitor of Trypanosoma cruzi (T. cruzi), the causative agent of Chagas disease, and the results of structure-activity investigations leading to potent analogues with low nM IC50s in a T. cruzi whole cell in vitro assay. Lead compounds suppressed blood parasitemia to virtually undetectable levels after once daily oral dosing in mouse models of T. cruzi infection. Compounds are chemically tractable, allowing rapid optimization of target biological activity and drug characteristics. Chemical and biological studies undertaken in the development of the fenarimol series toward the goal of delivering a new drug candidate for Chagas disease are reported.
- Keenan, Martine,Abbott, Michael J.,Alexander, Paul W.,Armstrong, Tanya,Best, Wayne M.,Berven, Bradley,Botero, Adriana,Chaplin, Jason H.,Charman, Susan A.,Chatelain, Eric,Von Geldern, Thomas W.,Kerfoot, Maria,Khong, Andrea,Nguyen, Tien,McManus, Joshua D.,Morizzi, Julia,Ryan, Eileen,Scandale, Ivan,Thompson, R. Andrew,Wang, Sen Z.,White, Karen L.
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p. 4189 - 4204
(2012/07/27)
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- Ligand-free Pd-catalyzed carbonylative cross-coupling reactions under atmospheric pressure of carbon monoxide: Synthesis of aryl ketones and heteroaromatic ketones
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The carbonylative Suzuki cross-coupling reactions of boronic acids with aryl iodides catalyzed by Pd2(dba)3 as a ligand-free catalyst under atmospheric pressure of carbon monoxide has been firstly developed. Under mild reaction conditions, a broad range of aryl/heteroaryl iodides and aryl/heteroaryl boronic acids were selectively coupled to afford the corresponding diaryl ketones in good to excellent yields at low catalyst loadings (0.05 to 2 mol-%). Moreover, the catalyst can also be recycled. The carbonylative Suzuki cross-coupling reactions of boronic acids with aryl iodides catalyzed by Pd2(dba)3 as a ligand-free catalyst under an atmosphere of carbon monoxide has been developed. A broad range of aryl/heteroaryl iodides and aryl/heteroaryl boronic acids were selectively coupled to afford the corresponding diaryl ketones in good to excellent yields. The catalyst can also be recycled.
- Li, Hongling,Yang, Min,Qi, Yanxing,Xue, Jijun
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supporting information; experimental part
p. 2662 - 2667
(2011/06/25)
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- A simple, efficient, and recyclable phosphine-free catalytic system for carbonylative suzuki coupling reaction of aryl and heteroaryl iodides
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The carbonylative Suzuki cross-coupling reaction of arylboronic acid with aryl and heteroaryl iodides using polymer supported palladium-N-heterocyclic carbene complex (PS-Pd-NHC) as an efficient heterogeneous, recyclable catalyst is described. The developed catalytic system is found to be effective for the carbonylative coupling reaction of aryl, heteroaryl, and bicyclic heteroaryl iodides (5-iodoindole and 3-iodoquinoline) with various arylboronic acid derivatives providing good to excellent yields of the desired products. The protocol is advantageous due to the ease in handling of the catalyst and simple workup procedure, and environmentally benign with effective catalyst recyclability. Georg Thieme Verlag Stuttgart - New York.
- Qureshi, Ziyauddin S.,Deshmukh, Krishna M.,Tambade, Pawan J.,Bhanage, Bhalchandra M.
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experimental part
p. 243 - 250
(2011/03/18)
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- Pd/C: An efficient, heterogeneous and reusable catalyst for phosphane-free carbonylative suzuki coupling reactions of aryl and heteroaryl iodides
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The carbonylative Suzuki coupling reaction of aryl boronic acid with different aryl and heteroaryl iodides was carried out to synthesize various unsymmetrical biaryl ketones by using Pd/C as an efficient, heterogeneous and reusable catalyst. The catalyst exhibits remarkable activity, and its reusability was tested up to four consecutive cycles. The reaction is applicable for various aryl and heteroaryl iodides having different steric and electronic properties. It provides good to excellent yield of the desired products. The developed protocol is advantageous with regard to the ease in handling the catalyst and the simple work-up procedure; it is also an environmentally benign process with effective catalyst recyclability. A facile protocol has been developed for the carbonylative Suzuki coupling reaction of aryl and heteroaryl iodides with Pd/C as effective, heterogeneous, reusable catalyst. The system is applicable for a wide variety of aryl and heteroaryl iodides. Copyright
- Khedkar, Mayur V.,Tambade, Pawan J.,Qureshi, Ziyauddin S.,Bhanage, Bhalchandra M.
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experimental part
p. 6981 - 6986
(2011/03/17)
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- Replacement of imidazolyl by pyridyl in biphenylmethylenes results in selective CYP17 and dual CYP17/CYP11B1 inhibitors for the treatment of prostate cancer
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Androgens are well-known to stimulate prostate cancer (PC) growth. Thus, blockade of androgen production in testes and adrenals by CYP17 inhibition is a promising strategy for the treatment of PC. Moreover, many PC patients suffer from glucocorticoid overproduction, and importantly mutated androgen receptors can be stimulated by glucocorticoids. In this study, the first dual inhibitor of CYP17 and CYP11B1 (the enzyme responsible for the last step in glucocorticoid biosynthesis) is described. A series of biphenylmethylene pyridines has been designed, synthesized, and tested as CYP17 and CYP11B1 inhibitors. The most active compounds were also tested for selectivity against CYP11B2 (aldosterone synthase), CYP19 (aromatase), and hepatic CYP3A4. In detail, compound 6 was identified as a dual inhibitor of CYP17/CYP11B1 (IC50 values of 226 and 287 nM) showing little inhibition of the other enzymes as well as compound 9 as a selective, highly potent CYP17 inhibitor (IC50 = 52 nM) exceeding abiraterone in terms of activity and selectivity.
- Hu, Qingzhong,Jagusch, Carsten,Hille, Ulrike E.,Haupenthal, J?rg,Hartmann, Rolf W.
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body text
p. 5749 - 5758
(2010/10/03)
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- Synthesis of 3-Aryl-3-pyridylallylamines Related to Zimelidine via Palladium-Catalyzed Amination
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Reaction of aryl pyridyl ketones 1 with vinylmagnesium bromide followed by acetylation of the products 2 with acetic anhydride/Et3N and with 4-(dimethylamino)pyridine (DMAP) as a catalyst gave acetates 3 in high yields.Treatment of acetates 3 with dimethylamine in the presence of a palladium catalyst produced a mixture of E and Z isomers of 3-aryl-3-pyridylallylamines 4.
- Baeckvall, Jan-E.,Nordberg, Ruth E.,Nystroem, Jan-E.,Hoegberg, Thomas,Ulff, Bengt
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p. 3479 - 3483
(2007/10/02)
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