- Cooperative N-Heterocyclic Carbene/Nickel-Catalyzed Hydroacylation of 1,3-Dienes with Aldehydes in Water
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The cooperative N-heterocyclic carbene/nickel-catalyzed redox-neutral hydroacylation of 1,3-dienes with aldehydes in water was reported. A wide range of aliphatic and aromatic aldehydes were directly coupled with 1,3-dienes, providing synthetically useful β,γ-unsaturated ketones or the corresponding ketones after hydrogenation in moderate to high yields and high atom economy. This protocol first demonstrated the compatibility of NHC catalysis with nickel catalysis. Water was used as the sole solvent, which is rarely reported in a cooperative metal/organic catalytic system.
- Gao, Zhong-Hua,Han, You-Feng,Liu, Hao,Wang, Congyang,Ye, Song,Zhang, Chun-Lin
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p. 1657 - 1663
(2022/01/28)
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- P-fluorobenzil type oxime ester photoinitiator used for preparing photochromic material as well as preparation method and application thereof
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The invention discloses a p-fluorobenzil type oxime ester photoinitiator for preparing a photochromic material as well as a preparation method and application thereof, and relates to the technical field of high-molecular materials. The photoinitiator disc
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Paragraph 0035-0039
(2021/10/27)
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- Catalyst-Free and Transition-Metal-Free Approach to 1,2-Diketones via Aerobic Alkyne Oxidation
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A catalyst-free and transition-metal-free method for the synthesis of 1,2-diketones from aerobic alkyne oxidation was reported. The oxidation of various internal alkynes, especially more challenging aryl-alkyl acetylenes, proceeded smoothly with inexpensive, easily handled, and commercially available potassium persulfate and an ambient air balloon, achieving the corresponding 1,2-diketones with up to 85% yields. Meanwhile, mechanistic studies indicated a radical process, and the two oxygen atoms in the 1,2-diketons were most likely from persulfate salts and molecular oxygen, respectively, rather than water.
- Shen, Duyi,Wang, Hongyan,Zheng, Yanan,Zhu, Xinjing,Gong, Peiwei,Wang, Bin,You, Jinmao,Zhao, Yulei,Chao, Mianran
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p. 5354 - 5361
(2021/05/05)
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- Ruthenium/dendrimer complex immobilized on silica-functionalized magnetite nanoparticles catalyzed oxidation of stilbenes to benzil derivatives at room temperature
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A new ruthenium/dendrimer complex stabilized on the surface of silica-functionalized nano-magnetite was fabricated and well characterized. The nano-catalyst showed good activity in the synthesis of benzil derivatives via the oxidation of stilbenes with high turnover frequency (TOF) at room temperature. Moreover, the catalyst could also be reused up to fifteen times without any loss of its activity.
- Ghanaatzadeh, Niloofar,Hashemi, Hajar,Moghadam, Majid,Niknam, Khodabakhsh,Saberi, Dariush
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- Ring Closing Metathesis Approach for the Synthesis of o-Terphenyl Derivatives
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A linear synthesis of o-terphenyl derivatives has been delineated using ring closing metathesis (RCM) as the key step. In this approach, benzil derivatives upon allyl Grignard addition provides diphenyl-1,2-diallyl dihydroxy derivatives which undergo ring closing metathesis to afford tetrahydro terphenyl derivatives. Aromatization-driven dehydration then leads to a diverse set of electron rich and electron deficient o-terphenyls. Furthermore, oxidative coupling of electron rich o-terphenyls provides the corresponding triphenylene derivatives.
- Karmakar, Shilpi,Mandal, Tirtha,Dash, Jyotirmayee
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p. 5916 - 5924
(2019/08/21)
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- ICl/AgNO3 Co-catalyzed radical oxidation of diaryl- A nd alkylarylalkynes into 1,2-diketones
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A novel ICl/AgNO3 co-catalyzed radical oxidation of diaryl- A nd alkylarylalkynes into 1,2-diketones is reported. The reaction proceeded smoothly under mild conditions and generated 1,2-diketones in moderate to good yields with a good tolerance of functional groups. Furthermore, the obtained C4-(1,2-diketoaryl)isoxazoles could react smoothly with 1,2-diaminobenzene to form C4-(3-arylquinoxalin-2-yl)isoxazoles. At last, a new one-pot strategy for the synthesis of quinoxalines from 1,2-diphenylethynes and 1,2-diaminobenzene is also reported.
- Yang, Wen,Chen, Yu,Yao, Yongqi,Yang, Xin,Lin, Qifu,Yang, Dingqiao
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p. 11080 - 11090
(2019/09/09)
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- Substituent Effect in the Synthesis of α,α-Dibromoketones, 1,2-Dibromalkenes, and 1,2-Diketones from the Reaction of Alkynes and Dibromoisocyanuric Acid
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Internal alkynes reacted with dibromoisocyanuric acid/H2O to afford α,α-dibromoketone and 1,2-diketone derivatives. Diarylalkynes with activating groups provided 1,2-diketone derivatives as the major products, whereas diarylalkynes with a non-activating group or alkylarylalkynes gave α,α-dibromoketone derivatives as the major products. In addition, diarylalkynes with deactivating groups provided 1,2-dibromoalkenes. The reaction was conducted at room temperature and showed good yields in most cases. Reaction pathways have been proposed on the basis of experimental observations and density functional theory (DFT) calculations. (Figure presented.).
- Cho, Eunjeong,Jayaraman, Aravindan,Lee, Junseong,Ko, Kyoung Chul,Lee, Sunwoo
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p. 1846 - 1858
(2019/03/07)
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- Electrochemical synthesis of 1,2-diketones from alkynes under transition-metal-catalyst-free conditions
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We report an electrochemical protocol for the direct oxidation of internal alkynes in air to provide 1,2-diketones. A variety of functional groups and heterocycle-containing substrates can be tolerated well under mild conditions.
- Zhou, Jie,Tao, Xiang-Zhang,Dai, Jian-Jun,Li, Chen-Guang,Xu, Jun,Xu, Hong-Mei,Xu, Hua-Jian
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supporting information
p. 9208 - 9211
(2019/08/07)
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- Umpolung Reactivity of Aldehydes toward Carbon Dioxide
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Carbon dioxide is an intrinsically stable molecule. Therefore, its activation requires extra energy input in the form of reactive reagents and/or activated catalysts and, often, harsh reaction conditions. Reported here is a direct carboxylation reaction of aromatic aldehydes with carbon dioxide to afford α-keto acids as added-value products. In situ generation of a reactive cyanohydrin was the key to the successful carboxylation reaction under operationally mild reaction conditions (25–40 °C, 1 atm CO2). The resulting α-keto acids served as a platform for α-amino acid synthesis by reductive amination reactions, illustrating the chemical synthesis of essential bioactive molecules from carbon dioxide.
- Juhl, Martin,Lee, Ji-Woong
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p. 12318 - 12322
(2018/09/10)
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- Silver-Catalyzed Decarboxylative Couplings of Acids and Anhydrides: An Entry to 1,2-Diketones and Aryl-Substituted Ethanes
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Silver-catalyzed oxidative decarboxylative couplings of carboxylic acids and anhydrides to produce 1,2-diketones and substituted ethanes were developed. This reaction allows the generation of acyl or alkyl radicals by decarboxylation of the corresponding α-keto acids, alkyl acids and anhydrides, which are sequentially coupled to efficiently construct a new C?C bond. This reaction represents a carboxylic acid decarboxylative alternative that employs a radical termination strategy. (Figure presented.).
- Zou, Hua-Xu,Li, Yang,Yang, Yuan,Li, Jin-Heng,Xiang, Jiannan
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supporting information
p. 1439 - 1443
(2018/02/26)
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- Magnetic magnetite nanoparticals catalyzed selective oxidation of Α-hydroxy ketones with air and one-pot synthesis of benzilic acid and phenytoin derivatives
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A clean and efficient protocol for selective oxidation of α-hydroxy ketones using magnetic magnetite nanoparticals (Fe3O4·MNPs) as catalyst with air as green oxidant has been developed. Application of Fe3O4·MNPs was also proved to be successful in one-pot synthesis of benzilic acid and phenytoin derivatives. The facile one-pot procedure enhanced the production efficiency, shortened the reaction time and minimized the chemical waste. Notably, the catalyst can be reused at least for five times without any appreciable loss of its activity.
- Li, Xiaona,Xia, Dandan,Wen, Zhiyong,Gong, Bowen,Sun, Maolin,Wu, Yue,Zhang, Jie,Sun, Jun,Wu, Yang,Bao, Kai,Zhang, Weige
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- CO2-assisted synthesis of non-symmetric α-diketones directly from aldehydes: Via C-C bond formation
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CO2-assisted various symmetric and non-symmetric α-diketones have been synthesized directly from the corresponding aldehydes using transition metal-free catalysts. This method can even be applied to synthesize pharmaceuticals directly from aldehydes. The crucial role of CO2 has been investigated in detail and the mechanism is proposed on the basis of experiments and DFT calculations.
- Hirapara, Pradipbhai,Riemer, Daniel,Hazra, Nabanita,Gajera, Jignesh,Finger, Markus,Das, Shoubhik
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supporting information
p. 5356 - 5360
(2017/11/22)
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- 2,3-Bis (4-fluorophenyl)-6,7-difluoroquinoxaline and preparation method thereof
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The invention discloses a novel compound 2,3-bis(4-fluorophenyl)-6,7-difluoroquinoxaline and a synthesis preparation method thereof. The molecular formula of the compound is C20H10F4N2, and has a structure represented by formula 1. The compound has wide bioactivities, is a novel anti-AIDS activity quinoxaline derivative, and can be used in the fields of antitumor agents, NMDA receptor antagonists, plant growth regulators, bactericides, fluorescent agents and dye intermediates. The compound can also be used in organic light emitting diodes, and different substituent groups with the adopting the compound as a ligand cause the change of the luminescent color, for example a novel iridium complex with the compound as a ligand has good red luminescence.
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- NaBrO3/bmim[HSO4]: a versatile system for the selective oxidation of 1,2-diols, α-hydroxyketones, and alcohols
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Abstract: Sodium bromate with bmim[HSO4] has been found to be an excellent oxidizing agent in aqueous medium. NaBrO3:bmim[HSO4] oxidized 1,2-diols, α-hydroxyketones, and alcohols to the corresponding carbonyl compounds in excellent yields. This method offers advantages such as low cost reagents, aqueous reaction conditions, moderate temperatures and short reaction times and hence environmentally benign reaction. Moreover, the ionic liquid bmim[HSO4] could be recycled for at least three times without loss of significant activity. Graphical abstract: [Figure not available: see fulltext.]
- Khurana, Jitender M.,Lumb, Anshika,Chaudhary, Ankita
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p. 381 - 386
(2017/02/10)
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- Synthesis and biological evaluation of novel 1,2,4-triazine derivatives bearing carbazole moiety as potent α-glucosidase inhibitors
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A new series of 1,2,4-triazine derivatives bearing carbazole moiety 7a-7p were designed, synthesized, and evaluated for their α-glucosidase inhibitory activity. The majority of the screened compounds displayed potent α-glucosidase inhibitory activity, with IC50 values in the range of 4.27 ± 0.07-47.75 ± 0.25 μM as compared to the standard drug acarbose. Among the series, compound 7k represented the most potent α-glucosidase inhibitory activity with IC50 values of 4.27 ± 0.07 μM. Kinetic analysis revealed that compound 7k is a non-competitive inhibitor with a Ki of 4.43 μM. Furthermore, the binding interactions of compound 7k with α-glucosidase was confirmed through molecular docking. This study showed these 1,2,4-triazine derivatives bearing carbazole moiety as a new class of α-glucosidase inhibitors.
- Wang, Guangcheng,Wang, Jing,He, Dianxiong,Li, Xin,Li, Juan,Peng, Zhiyun
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p. 2806 - 2809
(2016/06/09)
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- Dendrimer-like core cross-linked micelle stabilized ultra-small gold nanoclusters as a robust catalyst for aerobic oxidation of α-hydroxy ketones in water
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As one of the most general and promising stabilizers, dendrimers have been widely used to prepare ultra-small gold nanoclusters. However, the complex synthesis of dendrimers hinders the further application of protected nanoclusters. Here we report a facile strategy to prepare an alternative material via core cross-linking of self-assembled micelles. The resulting dendrimer-like core cross-linked micelles (DCCMs) retain the main characteristics of dendrimers and avoid complex chemical synthesis. As expected, the DCCMs could easily encapsulate gold nanoparticles within their cores. The ultra-small clusters of Au5 were prepared without the participation of external reductants. Importantly, the DCCM stabilized noble gold clusters furnish excellent catalytic activity and perfect reusability for aerobic oxidation of α-hydroxy ketones in water. Only in open air the oxidation could be repeated up to 48 times with negligible turn-over frequency change. The total turnover number (TON) of the reaction reached unexpectedly >48 000, the highest TON for metal catalysed oxidation of hydroxy ketones so far. The further mechanism study hints that the carboxylic group of substrates might be involved in the catalytic process. The simple catalyst preparation, the environmentally benign reaction conditions, and the excellent catalytic performance and durability make the novel DCCM protected gold nanocluster a green catalyst.
- Yu, Yangyang,Lin, Chenlu,Li, Bing,Zhao, Pengxiang,Zhang, Shiyong
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p. 3647 - 3655
(2016/07/06)
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- Synthesis of ferrocene derivatives with planar chirality via palladium-catalyzed enantioselective C-H bond activation
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The first catalytic and enantioselective C-H direct acylation of ferrocene derivatives has been developed. A series of 2-acyl-1-dimethylaminomethylferrocenes with planar chirality were provided under highly efficient and concise one-pot conditions with up to 85% yield and 98% ee. The products obtained could be easily converted to various chiral ligands via diverse transformations.
- Pi, Chao,Cui, Xiuling,Liu, Xiuyan,Guo, Mengxing,Zhang, Hanyu,Wu, Yangjie
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p. 5164 - 5167
(2014/12/11)
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- Benzoin condensation and stetter reaction catalysed by N,N-dimethylbenzimidazolium iodide in [Bmim][OH]
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N,N-Dimethylbenzimidazolium iodide catalysed benzoin condensation and Stetter reaction in 1-butyl-3-methylimidazolium hydroxide [bmim][OH] which acts as a basic catalyst as well as a solvent for the reactions are described. The recycled reaction media containing benzimidazolium salt can be reused for several times without significant loss of efficiency.
- Phungpis, Baramee,Hahnvajanawong, Viwat,Theramongkol, Parinya
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p. 933 - 939
(2015/02/19)
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- Copper-catalyzed aerobic oxidative C-C bond cleavage of 1,3-diaryldiketones to synthesize 1,2-diketones
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An aerobic oxidative C-C bond cleavage of 1,3-diaryldiketones for the synthesis of 1,2-diketones by using O2 as the oxidant has been developed. Control experiments illustrate that the copper catalyst not only assist the aerobic oxidative process of 1,3-diketones, but also catalyze the 1,2-Wagner-Meerwein-type rearrangement process. Georg Thieme Verlag Stuttgart. New York.
- Zhang, Chun,Wang, Xiaoyang,Jiao, Ning
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supporting information
p. 1458 - 1460
(2014/06/23)
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- HETEROCYCLIC COMPOUNDS FOR THE INHIBITION OF PASK
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Disclosed herein are new heterocyclic compounds of Formula IIa: and compositions thereof, and their application as pharmaceuticals for the treatment of disease. Methods of inhibiting PAS Kinase (PASK) activity in a human or animal subject are also provided for the treatment of diseases such as diabetes mellitus.
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- Unexpected transformation of aldehydes into benzoins with Copper(I)/Samarium
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The reductive coupling of aldehydes to afford pinacolic alcohols using all kinds of reducing agents involving samarium is well known. In this report, however, treatment of aromatic aldehydes with Cu(I)/Sm system produces benoins and/or benzils in good yields. A possible mechanism is proposed where Cu(I) not only activates the Sm metal but also promotes the dehydrogenation of the intermediates, during which a Cu(III) species may be involved. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Liu, Yongjun,Wang, Hui,Fu, Yulong,Qi, Yan,Yang, Kuiwei
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p. 259 - 266
(2013/12/04)
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- CuI-catalyzed and air promoted oxidative cyclization for one-pot synthesis of polyarylated oxazoles
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A facile CuI-catalyzed and air promoted oxidative cyclization was developed for the synthesis of polyarylated oxazoles. By virtue of this method, a variety of arylated oxazoles could be easily synthesized from readily available starting materials at room temperature in air. The Royal Society of Chemistry 2013.
- Hu, Ping,Wang, Qiang,Yan, Yizhe,Zhang, Shuai,Zhang, Baiqun,Wang, Zhiyong
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supporting information
p. 4304 - 4307
(2013/08/23)
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- YbCl3-catalyzed one-pot synthesis of dihydropyrazines, piperazines, and pyrazines
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A simple and efficient synthetic approach to dihydropyrazines via YbCl 3-catalyzed reaction of α-hydroxyketones with diamines under mild conditions was developed. The corresponding 2,3-subsitituted piperazines and pyrazines were obtained through tandem conversion of dihydropyrazines with good yields.
- Fan, Liyan,Chen, Wen,Qian, Changtao
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supporting information
p. 231 - 234
(2013/02/23)
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- N-heterocyclic carbene-catalyzed annulation of α-cyano-1,4-diketones with ynals
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In this paper, the first stereoselective annulation reaction between r-cyano-1,4-diketones and ynals, mediated by catalytic amounts of a triazolium salt precatalyst and cocatalytic amounts of a weak carboxylate base, is disclosed. The title transformation proceeds smoothly under mild reaction conditions and generates three contiguous stereogenic centers, one of which is a quaternary acetal carbon. This reaction tolerates a wide variety of electronically distinct substituents on both reaction partners and affords privileged bicyclic scaffolds in 61-90% isolated yields and with up to 20:1 diastereomeric preference.
- Romanov-Michailidis, Fedor,Besnard, Celine,Alexakis, Alexandre
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p. 4906 - 4909,4
(2012/12/12)
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- N-heterocyclic carbene-catalyzed annulation of α-cyano-1,4-diketones with ynals
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In this paper, the first stereoselective annulation reaction between r-cyano-1,4-diketones and ynals, mediated by catalytic amounts of a triazolium salt precatalyst and cocatalytic amounts of a weak carboxylate base, is disclosed. The title transformation proceeds smoothly under mild reaction conditions and generates three contiguous stereogenic centers, one of which is a quaternary acetal carbon. This reaction tolerates a wide variety of electronically distinct substituents on both reaction partners and affords privileged bicyclic scaffolds in 61-90% isolated yields and with up to 20:1 diastereomeric preference.
- Romanov-Michailidis, Fedor,Besnard, Céline,Alexakis, Alexandre
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p. 4906 - 4909
(2013/01/15)
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- Synthesis of electron-poor hexa-peri-hexabenzocoronenes
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The oxidative cyclodehydrogenation of electron-poor arenes was achieved using DDQ-CF3SO3H resulting in hexa-peri- hexabenzocoronenes with electron withdrawing Br, F and CF3 groups. This method will lead to their expansion into a new class of electron transport materials.
- Jones, David J.,Purushothaman, Balaji,Ji, Shaomin,Holmes, Andrew B.,Wong, Wallace W. H.
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supporting information; experimental part
p. 8066 - 8068
(2012/09/22)
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- Direct carbo-acylation reactions of 2-arylpyridines with α-diketones via Pd-catalyzed C-H activation and selective C(sp2)-C(sp2) cleavage
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An efficient carbo-acylation reaction of 2-arylpyridines with α-diketones via Pd-catalyzed C-H bond activation and C-C bond cleavage in the presence of TBHP was developed that generated aryl ketones in good yields. The highly selective formation of aryl ketones was observed when 2-arylpyridines reacted with aromatic/aliphatic α-diketones.
- Zhou, Wei,Li, Hongji,Wang, Lei
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supporting information
p. 4594 - 4597
(2012/10/29)
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- Iron(III)-catalyzed nucleophilic substitution of the hydroxy group in benzoin by alcohols
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The etherification reaction between benzoin derivatives and alcohols catalyzed by iron(III) proceeds in moderate to good yields. Other metal complexes showed either low reactivity or low chemoselectivity where oxidation of benzoin to benzil was a competing reaction. The iron source operated as a catalyst where 5 mol% of iron(III) generate the 2-alkoxy-1,2-diphenylethan-1-one in 50% yield. With an optimum of 25 mol% of catalyst, the desired ether was obtained in 85% yield. The etherification of benzoin and an alcohol proceed to generate the desired product in polar solvents such as 1,2-dichloroethane, whereas less polar solvents promote the competing oxidation to generate the benzil; polar coordinating solvents such as tetrahydrofuran inhibited the reaction. The efficiency of the reaction is found to be dependent on nucleophile where an optimum of 30 equivalents of alcohol was observed. With electron-donating substituents on the aromatic ring, the etherification was followed by oxidation to generate the benzil. Moderate yields of etherification product were obtained by monitoring the reaction progress with electron-rich substrates and quenching the reaction after two hours. Georg Thieme Verlag Stuttgart New York.
- Mirzaei, Anvar,Biswas, Srijit,Samec, Joseph S. M.
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experimental part
p. 1213 - 1218
(2012/06/04)
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- Analysis of the inhibition of mammalian carboxylesterases by novel fluorobenzoins and fluorobenzils
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We have synthesized and assessed the ability of symmetrical fluorobenzoins and fluorobenzils to inhibit mammalian carboxylesterases (CE). The majority of the latter were excellent inhibitors of CEs however unexpectedly, the fluorobenzoins were very good enzyme inhibitors. Positive correlations were seen with the charge on the hydroxyl carbon atom, the carbonyl oxygen, and the Hammett constants for the derived Ki values with the fluorobenzoins.
- Hicks, Latorya D.,Hyatt, Janice L.,Moak, Teri,Edwards, Carol C.,Tsurkan, Lyudmila,Wierdl, Monika,Ferreira, Antonio M.,Wadkins, Randy M.,Potter, Philip M.
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p. 3801 - 3817
(2008/02/09)
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- Oxidative cleavage of vicinal diols: IBX can do what Dess-Martin periodinane (DMP) can
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A study was conducted to demonstrate the similarity of reactivity between o-iodoxybenzoic acid (IBX), an oxidative agent of vicinal diols and Des-Martin periodinane (DMP). The study examined IBX-mediated oxidative cleavage of tert,tert-1,2-diols and discovered pathways that favored fragmentation of sec,sec-1,2-diols, which produce non-cleavage products. It was observed that IBX can be employed to perform oxidative cleavage of 1,2-diols similar to DMP by simple variation of solvent and temperature. It was also observed that protonation of 10-1-4 species of diols may suppress the nucleophilic attack, leading to the production of ketol to achieve oxidative cleavage of sec,sec-1,2-diols that yield non-cleavage products with IBX in DMSO. TFA was used as a significant source of protons and a better solvent of IBX to conduct protonation of diols. A variety of sec,sec,tert,tert and sec,tert syn-1,2-diols underwent oxidative cleavage effectively, using TFA as a solvent.
- Moorthy, Jarugu Narasimha,Singhal, Nidhi,Senapati, Kalyan
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p. 767 - 771
(2008/03/27)
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- Heat- or singlet oxygen-generating agents and cancer treatment compositions comprising organic peroxide or chemiluminescent compound
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The present invention provides a heat-generating agent or singlet oxygen-generating agent effective as a new cancer treatment agent which, unlike an anticancer agent based on an alkylating agent such as MMC, uses the action of heat and/or singlet oxygen to kill cancer cells and reduce the burden on patients. A heat- and/or singlet oxygen-generating agent or a cancer treatment agent, comprising an organic peroxide such as the peroxide of an imidazole derivative or a chemiluminescent compound such as a dioxetane compound.
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Page/Page column 5
(2008/06/13)
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- Hyperbranched polyphenylquinoxalines from self-polymerizable AB 2 and A2B monomers
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A self-polymerizable AB2 monomer, 2,3-bis(4-hydroxyphenyl)-6-fluoroquinoxaline, and an A2B monomer, 2,3-bis(4-fluorophenyl)-6-(4-hydrcixyphenoxy)quinoxaline) were prepared and polymerized to afford phenol-terminated and aryl fluoride terminated, hyperbranched polyphenylquinoxalines (HPPQs), respectively. MALDI-TOF analysis showed that intramolecular cyclization was a dominant process for the low molecular weight portion during the polymerizations. After isolation and complete dryness, the phenol-terminated HPPQ 1 was only soluble in strong organic acids, while the aryl fluoride terminated HPPQ 2 was soluble in most common organic solvents. HPPQ 1 was treated with allyl bromide to afford an allyl ether terminated HPPQ 3, which was also soluble in most organic solvents. Intrinsic viscosity measurements and SEC analysis indicated that HPPQ 2 had a much higher Mw and a much broader molecular weight distribution (PDI ~ 60) than HPPQ 1 and HPPQ 3 (PDI ~ 4). The results also suggested that HPPQ 1 formed aggregates in solution and that HPPQ 2 had a much more extended and open conformation. All the HPPQs, which were highly fluorescent, had UV absorption maxima near 375 nm in THF. However, the wavelength of their emission maxima, which ranged from 424 to 466 nm, depended on their end groups.
- Back, Jong-Beom,Harris, Frank W.
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p. 297 - 306
(2007/10/03)
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- 1-Benzhydryl-3-phenylurea and 1-benzhydryl-3-phenylthiourea derivatives: New templates among the CB1 cannabinoid receptor inverse agonists
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New 1-benzhydryl-3-phenylurea derivatives and their 1-benzhydryl-3- phenylthiourea isosteres were synthesized and evaluated for their human CB 1 and CB2 cannabinoid receptor affinity. These compounds proved to be selective CB1 cannabinoid receptor ligands, acting as inverse agonists in a [35S]-GTPγS assay. The affinity of 3,5,5′-triphenylimidazolidine-2,4-dione and 3,5,5′-triphenyl-2- thioxoimidazolidin-4-one derivatives, possessing the 1-benzhydryl-3-phenylurea and 1-benzhydryl-3-phenylthiourea moiety, respectively, was also evaluated. In conclusion, the 1-benzhydryl-3-phenylurea scaffold seems to be a new interesting template of CB1 cannabinoid receptor inverse agonists.
- Muccioli, Giulio G.,Wouters, Johan,Scriba, Gerhard K. E.,Poppitz, Wolfgang,Poupaert, Jacques H.,Lambert, Didier M.
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p. 7486 - 7490
(2007/10/03)
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- 3,6-DISUBSTITUTED AZABICYCLO [3.1.0] HEXANE DERIVATIVES AS MUSCARINIC RECEPTOR ANTAGONISTS
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The invention relates to derivatives of 3,6-disubstituted azabicyclo [3.1.0] hexanes of structure (I). The compounds of this invention can function as muscarinic receptor antagonists, and can be used for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems mediated through muscarinic receptors. The invention also relates to pharmaceutical compositions containing the compounds of the present invention and the methods for treating the diseases mediated through muscarinic receptors.
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- SUBSTITUTED AZABICYCLO HEXANE DERIVATIVES AS MUSCARINIC RECEPTOR ANTAGONISTS
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This invention relates to derivatives of substituted azabicyclo hexanes.The compound of this invention can function as muscarinic receptor antagonists, and can be used for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems mediated through muscarinic receptors.The invention also relates to a process for the preparation of compounds of the present invention, pharmaceutical compositions containing the compounds of the present invention and the methods of treating the diseases mediated through muscarinic receptors.
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- Versatile access to benzhydryl-phenylureas through an unexpected rearrangement during microwave-enhanced synthesis of hydantoins
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(Equation presented) A new access to benzhydryl-phenylureas is described. These new interesting urea derivatives were obtained by reaction of substituted benzils with substituted phenylureas under microwave irradiation. Phenylthiourea, when reacted with benzil, gave 3-phenyl-thiohydantoin. Moreover, benzylurea, as phenethylurea, gave the corresponding 3-substituted hydantoin derivatives, demonstrating that only phenylurea derivatives can result in benzhydryl-phenylureas under the applied conditions. This new reaction proved to be an easy access to substituted 1-benzhydryl-3-phenyl-ureas.
- Muccioli, Giulio G.,Wouters, Johan,Poupaert, Jacques H.,Norberg, Bernadette,Poppitz, Wolfgang,Scriba, Gerhard K. E.,Lambert, Didier M.
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p. 3599 - 3602
(2007/10/03)
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- Fluorinated benzils and a process for their preparation
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Fluorinated benzils and a process for their preparation A process for the preparation of fluorinated benzils of the formula (1) STR1 in which X1 -X6, R1, R2, R3 and R4 are hydrogen, fluorin
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- α-Keto Amides and 1,2-Diketones from N,N'-Dimethoxy-N,N'-dimethylethanediamide. A Synthetic and Mechanistic Investigation
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N,N'-Dimethoxy-N,N'-dimethylethanediamide (1), a 1,2-dicarbonyl synthon prepared from oxalyl chloride, undergoes nucleophilic displacements with Grignard reagents to provide α-keto amides 2-12 in 28-90percent yields.The synthon also undergoes double nucleophilic displacements with organolithium reagents to furnish symmetrical 1,2-diketones 15-23 in 15-84percent yields.A mechanism accounting for all the products from the reaction of 1 with nucleophiles has been proposed.Several control experiments were carried out to support the proposed mechanism.
- Sibi, Mukund P.,Marvin, Mali,Sharma, Rajiv
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p. 5016 - 5023
(2007/10/03)
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- Cobalt catalysed synthesis of 1,2-diones from aromatic aldehydes in the presence of n-butanal
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Cobalt(II) chloride catalyses the oxidative coupling of a wide range of aromatic aldehydes in the presence of dioxygen to afford 1,2-diones or carboxylic acids. Aromatic aldehydes may be transformed to 1,2-diones in the presence of n-butanal whereas the presence of acetic anhydride and n-butanal lead to the formation of the corresponding carboxylic acids.
- Punniyamurthy,Kalra, Swinder Jeet Singh,Iqbal, Javed
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p. 2959 - 2960
(2007/10/02)
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- A convenient preparation of symmetrical and unsymmetrical 1,2-diketones: Application to fluorinated phenytoin synthesis
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1,2-Diketones are efficiently produced in two steps by reaction of aldehydes with anions derived from 2-substituted dithianes followed by treatment of the resulting alcoholis with NBS in aqueous acetone; phenytoin derivatives were prepared from these diketones by a standard method involving treatment with urea and potassium hydroxide under reflux.
- Page,Graham,Park
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p. 7265 - 7274
(2007/10/02)
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- STRUCTURES IN SOLUTION OF ADDUCTS OF 2,8-DIOXA-5-AZA-1-PHOSPHABICYCLOOCTANE AND SUBSTITUTED BENZILS
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Adducts of 2,8-dioxa-5-aza-1-phosphabicyclooctane and p,p'-dimethylbenzil, p-methoxy-p'-fluorobenzil, p-fluorobenzil, p,p'-difluorobenzil, p-nitrobenzil and p,p'-dinitrobenzil have been prepared.Although these materials could not be isolated in pure form because of rapid decomposition, the 31P and other NMR spectral data indicate that all of these materials are pentacoordinate in solution.The NMR data also indicate that all of these adducts undergo rapid intramolecular ligand reorganosation at room temperature.Variable temperature NMR measurements indicate that these rearrangements can be slowed and that they all have virtually the same activation energies, ΔG(excit.) 11.4-11.9 kcal/mole.The barrier to ligand reorganization is associated with the 5-membered dioxa containing ring adopting a diequatorial disposition.These results are discussed and compared to other systems.
- Denney, Donald B.,Denney, Dorothy Z.,Pastor, Stephen D.
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p. 191 - 198
(2007/10/02)
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- STRUCTURES IN SOLUTION OF ADDUCTS OF HEXAMETHYLPHOSPHORUS TRIAMIDE AND SUBSTITUTED BENZILS
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Hexamethylphosphorus triamide has been allowed to react with p,p'-dinitrobenzil, p-chlorobenzyl, p,p'-difluorobenzil, p,p'-dimethylbenzil and p,p'-dimethoxybenzil.All of these materilas in benzene-d6 had negative δ 31P chemical shifts except for the p,p'-
- Denney, Donald B.,Pastor. Stephen D.
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p. 239 - 246
(2007/10/02)
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- 3-Amino-5,6-diaryl-1,2,4-triazines
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This invention relates to certain 3-amino-5,6-diaryl-1,2,4-triazines useful as anti-inflammatory agents and a method of treating inflammation.
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- Preparation and antiinflammatory activity of some nonacidic trisubstituted imidazoles
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A number of trisubstituted imidazoles were made and several found to be potent antiinflammatory agents when examined in the carrageenan rat paw edema test. The antiinflammatory activity of these compounds is retained in adrenalectomized rats. Unlike many previously reported antiinflammatory agents, these compounds are extremely weak acids pK[a] ≥ 11) and are therefore not ionized at physiological pH. One compound, 4,5 bis (4 methoxyphenyl) 2 trifluoromethylimidazole (flumizole), is more potent than indometacin in the rat paw edema test and, in contrast to some related compounds, does not cause photosensitization in mice.
- Lombardino,Wiseman
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p. 1182 - 1188
(2007/10/04)
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