- Mild Darzens Annulations for the Assembly of Trifluoromethylthiolated (SCF3) Aziridine and Cyclopropane Structures
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We report mild new annulation approaches to trisubstituted trifluoromethylthiolated (SCF3) aziridines and cyclopropanes via Darzens inspired protocols. The products of these anionic annulations, rarely studied previously, possess attractive features rendering them valuable building blocks for synthesis platforms. In this study, trisubstituted acetophenone nucleophiles bearing SCF3 and bromine substituents in their α position were shown to undergo [2 + 1] annulations with vinyl ketones and tosyl-protected imines under mild reaction conditions.
- Delost, Michael D.,Njardarson, Jon T.
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supporting information
p. 6121 - 6125
(2021/08/16)
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- Exploiting excited-state aromaticity to design highly stable singlet fission materials
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Singlet fission, the process of forming two triplet excitons from one singlet exciton, is a characteristic reserved for only a handful of organic molecules due to the atypical energetic requirement for low energy excited triplet states. The predominant strategy for achieving such a trait is by increasing ground state diradical character; however, this greatly reduces ambient stability. Herein, we exploit Baird's rule of excited state aromaticity to manipulate the singlet-triplet energy gap and create novel singlet fission candidates. We achieve this through the inclusion of a [4n] 5-membered heterocycle, whose electronic resonance promotes aromaticity in the triplet state, stabilizing its energy relative to the singlet excited state. Using this theory, we design a family of derivatives of indolonaphthyridine thiophene (INDT) with highly tunable excited state energies. Not only do we access novel singlet fission materials, they also exhibit excellent ambient stability, imparted due to the delocalized nature of the triplet excited state. Spin-coated films retained up to 85% activity after several weeks of exposure to oxygen and light, while analogous films of TIPS-pentacene showed full degradation after 4 days, showcasing the excellent stability of this class of singlet fission scaffold. Extension of our theoretical analysis to almost ten thousand candidates reveals an unprecedented degree of tunability and several thousand potential fission-capable candidates, while clearly demonstrating the relationship between triplet aromaticity and singlet-triplet energy gap, confirming this novel strategy for manipulating the exchange energy in organic materials.
- Fallon, Kealan J.,Budden, Peter,Salvadori, Enrico,Ganose, Alex M.,Savory, Christopher N.,Eyre, Lissa,Dowland, Simon,Ai, Qianxiang,Goodlett, Stephen,Risko, Chad,Scanlon, David O.,Kay, Christopher W. M.,Rao, Akshay,Friend, Richard H.,Musser, Andrew J.,Bronstein, Hugo
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supporting information
p. 13867 - 13876
(2019/09/30)
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- Potent aromatase inhibitors and molecular mechanism of inhibitory action
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Estrogen is a significant factor in the maintenance and progression of hormone-dependent breast cancer. As well known, aromatase mediates the production of estrogen. Thus, inhibition of aromatase with chemical molecules has been considered to be an effective treatment for estrogen receptor-positive (ER+) breast cancer. In this work, we designed and synthesized a series of novel non-steroidal molecules containing 2-phenylindole scaffold and moiety of either imidazole or 1,2,4-triazole to enhance their binding capacity with the aromatase. Among these molecules, a compound named as 8o was confirmed experimentally to have the highest inhibitory activity to aromatase. Further cell activity assay proved that compound 8o has low cytotoxicity and is a promising lead for developing novel aromatase inhibitors. Molecular modeling and simulation techniques were performed to identify the binding modes of letrozole and 8o with the aromatase. Analysis of energy of the two compound-aromatase complexes revealed that the 8o has low binding energy (strong binding affinity) to the aromatase as compared to letrozole, which was in accordance with the experimental results. As concluded, a combination of experimental and computational approaches facilitates us to understand the molecular mechanism of inhibitory action and discover more potent non-steroidal AIs against aromatase, thereby opening up a novel therapeutic strategy for hormone-dependent breast cancer.
- Kang, Hongjun,Xiao, Xingqing,Huang, Chao,Yuan, Yan,Tang, Dongyan,Dai, Xiaochang,Zeng, Xianghui
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p. 426 - 437
(2017/12/07)
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- The novel usage of thiourea nitrate in aryl nitration
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Thiourea nitrate (TN) was easily prepared from thiourea and nitric acid to explore its use as a new nitration reagent. Nitrations of various aromatic compounds utilizing TN in concentrated sulfuric acid were studied. TN could convert aromatic compounds to the corresponding nitrated derivatives with various abnormal yields under mild conditions. The results suggested that the reaction mechanism might be different from those of traditional nitration reagents.
- Meng, Ge,Zheng, Mei-Lin,Zheng, A-Qun,Wang, Mei,Shi, Juan
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- Synthetic studies on indolocarbazoles: Total synthesis of staurosporine aglycon
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A synthesis of staurosporine aglycon and its analogs was achieved in a 28-36% overall yield starting from 2-methylindole. The prominent key steps for the synthesis of the indolocarbazole alkaloids involved electrocyclization and nitrene insertion reactions.
- Rajeshwaran, Ganesan Gobi,Mohanakrishnan, Arasambattu K
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p. 1418 - 1421
(2011/05/04)
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- A highly selective tandem cross-coupling of gem-dihaloolefins for a modular, efficient synthesis of highly functionalized indoles
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(Chemical Equation Presented) A highly efficient method of indole synthesis using gem-dihalovinylaniline substrates and an organoboron reagent was developed via a Pd-catalyzed tandem intramolecular amination and an intermolecular Suzuki coupling. Aryl, alkenyl, and alkyl boron reagents are all successfully employed, making for a versatile modular approach. The reaction tolerates a variety of substitution patterns on the aniline leading to indoles with group at C2-C7. The orthogonal approach of the sequential copper- and palladium-mediated synthesis of 1,2-diarylindoles exploited the wide availability of diverse organoboron reagents.
- Fang, Yuan-Qing,Lautens, Mark
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p. 538 - 549
(2008/09/17)
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- PYRROLOPYRIDINE-2-CARBOXYLIC ACID AMIDES
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Compounds represented by Formula (I) or pharmaceutically acceptable salts thereof, are useful in the prophylactic or therapeutic treatment of diabetes, hyperglycemia, hypercholesterolemia, hyperinsulinemia, hyperlipidemia, hypertension, atherosclerosis or tissue ischemia e.g. myocardial ischemia, and as cardioprotectants.
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Page/Page column 29
(2008/06/13)
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- 1H-2,1,3-benzothiadiazine-2,2-dioxide compounds or derivatives thereof
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A pharmaceutical compound having the formula: STR1 in which n is 1 or 2, m is 1 or 2, p is 1 to 6, q is 0 or 1 to 3, R1 and R2 are each hydrogen or C1-4 alkyl, R3, R4 and R5 are each hydrogen, C1-4 alkyl, optionally substituted phenyl or optionally substituted phenyl-C1-4 alkyl, or R3 and R4 together form an alkylene link of formula --(CH2)3 -- or --(CH2)4 --, or R4 and R5 together with the carbon atom to which they are attached form a C3-6 cycloalkyl group, R6 is C1-4 alkyl, C1-4 alkoxy, carboxy, hydroxy, cyano, halo, trifluoromethyl, nitro or amino, the dotted line represents an optional double bond, and the fluorine atom is attached at the 6 or 7-position; and salts and esters thereof.
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- Benzothiadiazinyl-indole derivatives and their use as serotonin receptor ligands
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Compounds having the formula: in which n is 1 or 2, m is 1 or 2, p is 1 to 6, q is 0 or 1 to 3, R1and R2are each hydrogen or C1-4alkyl, R3, R4and R5are each hydrogen, C1-4alkyl, optionally substituted phenyl or optionally substituted phenyl-C1-4alkyl, or R3and R4together form an alkylene link of formula -(CH2)3- or -(CH2)4-, or R4and R5together with the carbon atom to which they are attached form a C3-6cycloalkyl group, R6is C1-4alkyl, C1-4alkoxy, carboxy, hydroxy, cyano, halo, trifluoromethyl, nitro or amino, the dotted line represents an optional double bond, and the fluorine atom is attached at the 6 or 7-position; and salts and esters thereof, are binding to the 5-HT serotonin receptor and are useful in the treatment of CNS disorders.
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