- Synthesis and evaluation of thiophene-based organic dyes containing a rigid and nonplanar donor with secondary electron donors for use in dye-sensitized solar cells
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We demonstrate herein the divergent synthesis of six dyes containing our originally developed rigid and nonplanar donor with three different secondary electron donors (SEDs), namely thiophene, 4-methoxybenzene, and diphenylethene. Evaluation of the photop
- Fuse, Shinichiro,Takahashi, Ryota,Maitani, Masato M.,Wada, Yuji,Kaiho, Tatsuo,Tanaka, Hiroshi,Takahashi, Takashi
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Read Online
- A phenyl-removal strategy for accessing an efficient dual-state emitter in the red/NIR region guided by TDDFT calculations
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The development of molecules with efficient dual-state emission in the red/NIR region is significant for their broader application prospects in the biological field, but still remains a great challenge. Guided by in-depth TDDFT calculations, herein we fir
- Jiang, Lixia,Liang, Kangli,Shao, Qingqing,Wang, Hongming,Wang, Yigang,Xia, Guomin
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- A kinetic, product and kinetic isotope effect investigation of the bromination of 1,1-diphenylethyIenes and of their 2,2-dideuterio derivatives
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The kinetics of bromination of 1,1-diphenylethylene (1a), 4-trifluoromethyl-1,1-diphenylethylene (1b), and 1-(3-trifluoromethylphenyl)-1-(4-trifluoromethylphenyl)ethylene (1c) and of their 2,2-dideuterio derivatives have been investigated in 1,2-dichloroe
- Bellucci, Giuseppe,Chiappe, Cinzia
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Read Online
- Visible-light-mediated radical addition/cyclization tandem reaction for the synthesis of 3-bromomethyl-3,4-dihydroisocoumarins
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A visible-light-mediated radical addition/cyclization tandem reaction for the synthesis of 3-bromomethyl-3,4-dihydroisocoumarins from 2-allylbenzaldehydes and diethyl 2,2-dibromomalonate is described. In this reaction, the bromine radical is generated fro
- Li, Xing-Meng,Qian, Zhu-Ming,He, Yan-Hong,Guan, Zhi
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- Light-Promoted Bromine-Radical-Mediated Selective Alkylation and Amination of Unactivated C(sp3)–H Bonds
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C–H functionalization has provided new opportunities to construct organic molecules in an atom- and step-economic manner, facilitating the derivatization of complex pharmaceutical compounds. However, because of the intrinsically high bond dissociation ene
- Jia, Penghao,Li, Qingyao,Poh, Wei Chuen,Jiang, Heming,Liu, Haiwang,Deng, Hongping,Wu, Jie
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- Bromination of organic molecules with polymer-supported bromine complexes
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Three types of bromine complexes with various polymers bearing basic units (pyridine, piperidine and piperazine) were investigated and the role of polymer matrices on reactivity was tested by three types of organic reactions: electrophilic addition, aroma
- Zupan,Segatin
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Read Online
- A perpendicular phenyl-induced exceedingly efficient solid-state excited state intramolecular proton transfer fluorophore based on 2-(2-hydroxyphenyl)benzothiazole
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Fluorescent solid-state organic materials have been intensively researched in recent years. In this study, two 2-(2-hydroxyphenyl)benzothiazole (HBT) derivatives: phenylethylene-modified HBT (HBT-s-Ph) and diphenylethylene-modified HBT (HBT-d-Ph), were sy
- Wang, Qin,Xu, Longfei,Niu, Yahui,Wang, Yuxiu,Yuan, Mao-Sen,Zhang, Yanrong
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Read Online
- Dibrominated addition and substitution of alkenes catalyzed by Mn2(CO)10
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A practical method for the dibromination of alkenes without using molecular bromine is consistently appealing in organic synthesis. Herein, we report Mn-catalyzed dibrominated addition and substitution of alkenes only with N-bromosuccinimide, producing a variety of synthetically valuable dibrominated compounds in moderate to high yields. This journal is
- Chan, Albert S. C.,Jiang, Yi,Meng, Shanshui,Song, Xianheng,Zhang, Hong,Zou, Yong
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supporting information
p. 13385 - 13388
(2021/12/17)
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- Bromination of 1,1-diarylethylenes with bromoethane
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Aliphatic bromide was used as a halogenation reagent in the presence of DMSO, resulting in 2,2-diarylvinyl bromides from the corresponding 1,1-diarylethylenes. This protocol not only provides a convenient and straightforward strategy for the rapid construction of various 2,2-diarylvinyl bromides without bromine and extra oxidants, but also can improve the atom economy of Kornblum oxidative reaction.
- Yu, Ze,Jiang, Jialiang,Chen, Hongtai,Tang, Xiangyang
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supporting information
p. 2544 - 2552
(2021/07/06)
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- Visible light-mediated metal-free double bond deuteration of substituted phenylalkenes
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Various bromophenylalkenes were reductively photodebrominated by using 1,3-dimethyl-2-phenyl-1H-benzo-[d]imidazoline (DMBI) and 9,10-dicyanoanthracene. With deuterated DMBI analogs (the most effective was DMBI-d11), satisfactory to excellent isotopic yields were obtained. DMBI-d11 could also be regenerated from the reaction mixtures with a recovery rate of up to 50%. The combination of the photodebromination reaction with conventional methods for bromoalkene synthesis enables sequential monodeuteration of a double bond without the necessity of a metal catalyst. This journal is
- Iakovenko, Roman,Hlavá?, Jan
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supporting information
p. 440 - 446
(2021/01/28)
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- Directing Group Enables Electrochemical Selectively Meta-Bromination of Pyridines under Mild Conditions
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Without the use of catalysts and oxidants, a facile and sustainable electrochemical bromination protocol was developed. By introducing the directing groups, the regioselectivity of pyridine derivatives could be controlled at themeta-position utilizing the inexpensive and safe bromine salts at room temperature. A variety of brominated pyridine derivatives were obtained in 28-95% yields, and the reaction could be readily performed at a gram scale. By combining the installation and removing the directing group, the concept ofmeta-bromination of pyridines could be verified.
- Wu, Yanwei,Xu, Shanghui,Wang, Hong,Shao, Dongxu,Qi, Qiqi,Lu, Yi,Ma, Li,Zhou, Jianhua,Hu, Wei,Gao, Wei,Chen, Jianbin
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supporting information
p. 16144 - 16150
(2021/07/19)
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- Iron-Catalyzed Reductive Vinylation of Tertiary Alkyl Oxalates with Activated Vinyl Halides
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We present herein a rare and efficient method for the creation of vinylated all carbon quaternary centers via Fe-catalyzed cross-electrophile coupling of vinyl halides with tertiary alkyl methyl oxalates. The reaction displays excellent functional group tolerance and broad substrate scope, which allows cascade radical cyclization and vinylation to afford complex bicyclic and spiral structural motifs. The reaction proceeds via tertiary alkyl radicals, and the putative vinyl-Br/Fe complexation appears to be crucial for activating the alkene and enabling a possibly concerted radical addition/C-Fe forming process.
- Chen, Haifeng,Gong, Hegui,Yao, Ken,Ye, Yang
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supporting information
(2020/03/13)
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- Method for synthesizing beta-bromostyrene through metal-free catalysis
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The invention discloses a method for synthesizing beta-bromostyrene through metal-free catalysis, and belongs to the technical field of organic chemistry. Substituted styrene 1 is used as a raw material and is reacted in the presence of a bromination reagent, sodium persulfate and dichloroethane, and the beta-bromostyrene compound 2 can be obtained in one step. The method is capable of solving thetechnical problem that in the traditional synthesis method, conversion into alkenyl boron, alkenyl silicon and other intermediates under the catalysis of noble metals and then further halogenation are needed; the defects of expensive reaction reagent, high catalytic cost, complex operation, incapability of large-scale preparation and the like in the traditional preparation method are avoided; byadopting the method, a series of beta-bromostyrene compounds can be obtained, and the method has a potential application prospect.
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Paragraph 0064-0066
(2020/02/06)
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- Facile Synthesis of β-Bromostyrenes by Direct Bromination of Styrenes with N -Bromosuccinimide and Sodium Persulfate
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A new, direct, efficient, and transition-metal-free method is reported for the synthesis of β-bromostyrenes from styrenes by using N -bromosuccinimide as the brominating reagent and sodium persulfate (Na 2S 2O 8) as the oxidant. This convenient and concise reaction is practical, operationally simple, and can be adapted for large-scale syntheses.
- Chen, Xuenian,Gao, Yan,Jing, Yi,Ma, Yan-Na,Zhao, Qianyi
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supporting information
(2020/09/09)
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- Electrochemical Oxidative Oxydihalogenation of Alkynes for the Synthesis of α,α-Dihaloketones
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An electrochemical oxydihalogenation of alkynes has been developed for the first time. Using this sustainable protocol, a variety of α,α-dihaloketones can be prepared with readily available CHCl3, CH2Cl2, ClCH2CH2Cl, and CH2Br2 as the halogen source under electrochemical conditions at room temperature.
- Meng, Xiangtai,Zhang, Yu,Luo, Jinyue,Wang, Fei,Cao, Xiaoji,Huang, Shenlin
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supporting information
p. 1169 - 1174
(2020/02/04)
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- Environmentally sustainable production and application of acyl phosphates
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A versatile and environmentally friendly synthetic method for the formation of acyl phosphates is reported. By employing electrochemical oxidative dehydrogenative coupling, this transformation features a broad range of substrates, as well as metal-free, o
- Cai, Hu,Fu, Zhengjiang,Guo, Shengmei,Li, Sen,Liang, Zhibin,Yan, Wenjie
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supporting information
p. 7343 - 7347
(2020/11/19)
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- Visible-light-promoted oxidative halogenation of (hetero)arenes
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Organic halides are critical building blocks that participate in various cross-coupling reactions. Furthermore, they widely exist as natural products and artificial molecules in drugs with important physiological activities. Although halogenation has been well studied, to the best of our knowledge, studies focussing on sensitive systems (e.g.aryl amines) have not been reported. Herein, we describe a compatible oxidative halogenation of (hetero)arenes with air as the oxidant and halide ions as halide sources under ambient conditions (visible light, air, aqueous system, room temperature, and normal pressure). Moreover, this protocol is practically feasible for gram-scale synthesis, showing potential for industrial application.
- Jiang, Xuefeng,Li, Yiming,Lu, Lingling
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supporting information
p. 5989 - 5994
(2020/10/18)
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- Halogenation of 1,1-diarylethylenes by N-halosuccinimides
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An efficient method for the preparation of 2,2-diarylvinyl halides from the corresponding 1,1-diarylethylenes has been developed. N-Halosuccinimides (N-bromosuccinimide or N-chlorosuccinimide) were used as the halogenation reagents. The practicability of this method is highlighted by its simple operation, broad substrate scope and capability for large-scale reaction.
- Zhang, Ge,Bai, Rui-Xue,Li, Chu-Han,Feng, Chen-Guo,Lin, Guo-Qiang
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p. 1658 - 1662
(2018/12/11)
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- Palladium-Catalyzed Domino Reaction for Stereoselective Synthesis of Multisubstituted Olefins: Construction of Blue Luminogens
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The first Pd-catalyzed multicomponent reaction of aryl iodides, alkenyl bromides, and strained alkenes has been developed, which allowed us to synthesize a variety of multisubsituted olefins in yields of 45-96% with excellent stereoselectivity. The configuration of the product was controlled by the configuration of the alkenyl bromides. Moreover, this practical methodology employing readily available substrates was found to be tolerant to a wide range of functional groups. Fifty six examples of highly stereoselective tri- or tetrasubstituted olefins have been successfully synthesized via this methodology. Most of the synthesized tetrasubstituted olefins are good aggregation-induced emission (AIE) luminogens.
- Hao, Tao-Tao,Liang, Hao-Ran,Ou-Yang, Ying-Han,Yin, Chang-Zhen,Zheng, Xue-Li,Yuan, Mao-Lin,Li, Rui-Xiang,Fu, Hai-Yan,Chen, Hua
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p. 4441 - 4454
(2018/04/26)
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- A para-C–H Functionalization of Aniline Derivatives via In situ Generated Bulky Hypervalent Iodinium Reagents
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A practical para-C-H functionalization of aniline derivatives has been developed using an in situ generated bulky hypervalent iodinium reagent. Para-iodo, bromo, chloro, nitro, trifluormethyl aniline derivatives can be obtained efficiently, in many cases in 10 min in a transition metal-free manner. Medicinal chemicals or intermediates can be purified without column chromatography or recrystallization, which significantly reduces the waste and simplifies the work-up process.
- Tian, Chao,Yao, Xu,Ji, Weizhe,Wang, Qian,An, Guanghui,Li, Guangming
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supporting information
p. 5972 - 5979
(2018/11/23)
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- Decarboxylative bromination of α,β-unsaturated carboxylic acids via an anodic oxidation
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A novel bromination of α,β-unsaturated carboxylic acids was developed via a decarboxylation by virtue of a direct anodic electro-oxidation. In this method, ammonium bromide was employed as a bromine source and the reaction features transition-metal-free, short time, and no additional supporting electrolyte.
- Bi, Mei-Xiang,Qian, Peng,Wang, Yu-Kang,Zha, Zheng-Gen,Wang, Zhi-Yong
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p. 1159 - 1162
(2017/06/19)
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- Conversion of thiols into sulfonyl halogenides under aerobic and metal-free conditions
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An environmentally benign, metal-free synthesis of sulfonyl chlorides and bromides from thiols in the presence of ammonium nitrate, an aqueous solution of HCl and HBr and oxygen as a terminal oxidant was developed. The reactivity of various substituted thiophenols, benzylic-, aliphatic- and heteroaromatic thiols was examined. Ammonium nitrate served as a source of nitrogen oxides (NO/NO2), which are the crucial players in a redox-catalytic cycle. Sulfonyl chlorides and bromides were isolated without extraction and "filtered" over a short pad of silica gel; the use of solvents was greatly reduced in comparison with traditional isolation and purification. A "one-pot" protocol for the conversion of thiol into sulfonamide is also demonstrated. Scale-up experiments on the preparation of sulfonyl chloride and bromide are shown. A possible reaction pathway is discussed.
- Jereb, Marjan,Hribernik, Luka
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p. 2286 - 2295
(2017/07/24)
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- Iodine-catalyzed transformation of aryl-substituted alcohols under solvent-free and highly concentrated reaction conditions
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Iodine-catalyzed transformations of alcohols under solvent-free reaction conditions (SFRC) and under highly concentrated reaction conditions (HCRC) in the presence of various solvents were studied in order to gain insight into the behavior of the reaction intermediates under these conditions. Dimerization, dehydration and substitution were the three types of transformations observed with benzylic alcohols. Dimerization and substitution reactions were predominant in the case of primary- and secondary alcohols, whereas dehydration prevailed in the case of tertiary alcohols. The relative reactivity of substituted 1-phenylethanols in I2-catalyzed dimerization under SFRC provided a good Hammett plot ρ+ = -2.8 (r2 = 0.98), suggesting the presence of electron-deficient intermediates with a certain degree of developed charge in the rate-determining step.
- Jereb, Marjan,Vra?i?, Dejan
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p. 747 - 762
(2018/01/17)
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- Transformation of tertiary benzyl alcohols into the vicinal halo-substituted derivatives using N-Halosuccinimides
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The efficiency of direct conversion of tertiary alcohols bearing a-hydrogen atom to vicinal halohydrins-chlorohydrins and bromohydrins-under green reaction conditions was tested preliminarily on modeltertiary benzyl alcohols. Tertiary alcohols were successfully directly halogenated to vicinal halohydrins with N-halosuccinimide in aqueous media. The efficiency of the reaction in water was significantly improved in the presence of sodium dodecyl sulphate as the surfactant.
- Ajvazi, Njomza,Stavber, Stojan
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supporting information
(2016/11/02)
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- Copper(ii)-catalyzed C5 and C7 halogenation of quinolines using sodium halides under mild conditions
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A simple and mild protocol for copper catalyzed halogenation of quinoline at C5 and C7 positions was developed, affording the desired remote C-H activation products in moderate to good yields. This reaction proceeds with low-cost sodium halides (NaX, X =
- Xu, Jun,Zhu, Xiaolei,Zhou, Guobin,Ying, Beibei,Ye, Pingping,Su, Lingying,Shen, Chao,Zhang, Pengfei
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supporting information
p. 3016 - 3021
(2016/03/19)
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- Binaphthalene derivatives, preparation method thereof and organic electronic device using the same
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The present invention relates to a new binaphthalene derivative, a preparation method thereof, and an organic electronic device using the same. The binaphthalene derivative according to the present invention can perform functions of hole injection and transportation, electron injection and transportation, or light emission in an organic electronic device including an organic light-emitting device, and the device according to the present invention has excellent characteristics in terms of efficiency, drive voltage and stability, and in particular excellent effects such as a low voltage and a long life time.
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Page/Page column 139
(2014/03/26)
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- H-β-zeolite catalyzed synthesis of β-bromostyrenes from styrene bromohydrins
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Synthesis of β-bromostyrenes from styrene bromohydrins using H-β-zeolite as catalyst under moderate conditions is reported. The catalyst could be regenerated and reused up to three consecutive cycles.
- Pappula, Venkatanarayana,Donthiri, Ramachandra Reddy,Darapaneni, Chandra Mohan,Subbarayappa, Adimurthy
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supporting information
p. 1793 - 1795
(2014/03/21)
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- Synthesis of substituted aryl enol ethers
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A facile route toward substituted aryl diarylvinyl ethers 4 is developed from CuI-mediated cross-coupling reaction of substituted phenols 2 with diarylvinyl bromides 3 in the presence of various bidentate-based ligands in DMF. Skeleton 3 is prepared by Yan's bromomethylenation of diarylketones 1 with CHBr3-TiCl4-Mg in the co-solvent of DME and CH2Cl2. The synthetic route obtains moderate yields from the one-step operation and the key structure of 4k is confirmed by X-ray crystallographic analysis. The CADD docking experiments of 4k have been included.
- Chang, Meng-Yang,Tai, Hang-Yi,Tsai, Chung-Yu,Chuang, Yi-Jing,Lin, Ying-Ting
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supporting information
p. 6482 - 6485
(2014/12/10)
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- A new entry of highly nucleophilic CHBr3-TiCl4-Mg system for the stereoselective synthesis of 1-alkenyl bromides
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This TiCl4-Mg promoted coupling of CHBr3 with various aldehydes and ketones, especially in sterically hindered or enolizable ketones, provides a simple, practical, and stereoselective carbonyl-bromomethylenation leading primarily to (E)-vinyl bromides.
- Bhorge, Yeshwant Ramchandra,Chang, Su-Haur,Chang, Cheng-Ta,Yan, Tu-Hsin
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experimental part
p. 4846 - 4851
(2012/08/07)
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- Selective aerobic oxidative dibromination of alkenes with aqueous HBr and sodium nitrite as a catalyst
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Various alkenes (internal, terminal, aryl and alkyl substituted) and 1,2-diphenylethyne were efficiently and selectively dibrominated using 2 equivalents of 48% aqueous hydrobromic acid, with air as an oxidant and sodium nitrite as a catalyst. Despite the presence of water, only trans dibromination occurred producing anti-1,2-dibromoalkanes and (E)-1,2-dibromo-1,2- diphenylethene. A comparison of resource demand, waste production and environmental, health and safety issues of the NaNO2 catalyzed aerobic bromination with molecular bromine and other oxidative bromination methods revealed that the proposed method is not only selective and effective but has a better environmental profile.
- Podgorsek, Ajda,Eissen, Marco,Fleckenstein, Jens,Stavber, Stojan,Zupan, Marko,Iskra, Jernej
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experimental part
p. 120 - 126
(2010/04/22)
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- NEW BINAPHTHALENE DERIVATIVES, PREPARATION METHOD THEREOF AND ORGANIC ELECTRONIC DEVICE USING THE SAME
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The present invention relates to a new binaphthalene derivative, a preparation method thereof, and an organic electronic device using the same. The binaphthalene derivative according to the present invention can perform functions of hole injection and transportation, electron injection and transportation, or light emission in an organic electronic device including an organic light- emitting device, and the device according to the present invention has excellent characteristics in terms of efficiency, drive voltage and stability, and in particular excellent effects such as a low voltage and a long life time.
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Page/Page column 31
(2010/11/27)
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- NOVEL IMIDAZOQUINAZOLINE DERIVATIVE, PROCESS FOR PREPARING THE SAME, AND ORGANIC ELECTRONIC DEVICE USING THE SAME
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The present invention relates to a novel imidazoquinazoline derivative, a process for preparing the same, and an organic electronic device using the same. The imidazoquinazoline derivative according to the present invention serves as hole injecting, hole transporting, electron injecting, electron transporting, or a light emitting material in an organic electronic device including an organic light emitting device, and the device according to the present invention exhibits excellent characteristics in efficiency, operating voltage, and stability.
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Page/Page column 29
(2010/11/27)
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- Double-spiro organic compounds and organic electroluminescent devices using the same
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Disclosed are double-spiro organic compounds and an organic electroluminescence (EL) device using the same. The double-spiro organic compounds are configured to have at least three planar and substantially linear moieties, such that one planar moiety is located between two neighboring planar moieties and that the intervening planar moiety shares an atom with each of the two neighboring planar moieties. The double-spiro compounds generally have high melting point above about 300 degree C. and low crystallinity, which provide thermal stability to the organic EL devices. These organic compounds have good sublimability. They also have light-emitting, hole-injecting, hole-transporting, electron injection, electron-transporting properties and characteristics, which are favorable in the organic EL devices.
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Page/Page column 48
(2010/02/15)
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- Halodephosphorylation of α,β-unsaturated phosphonic acid monoesters
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Reaction of α,β-ethylenic and acetylenic phosphonic acid monoesters with (biscollidine)iodine(I) or (biscollidine)bromine(I) hexafluorophosphate led to α,β-unsaturated halides by, without precedent, dephosphorylation reactions.
- Lahrache, Hind,Robin, Sylvie,Rousseau, Gérard
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p. 1635 - 1637
(2007/10/03)
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- 2,2-(Diaryl)vinylphosphine compound, palladium catalyst thereof, and process for producing arylamine, diaryl, or arylalkyne with the catalyst
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A novel 2,2-(diaryl)vinylphosphine compound represented by the following general formula (1): (wherein R1 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 5 to 7 carbon atoms, etc.; R2, R3, R4, R5, R6, and R7 may be the same or different and each is an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 5 to 7 carbon atoms, etc., provided that R4 and R5 taken together and/or R6 and R7 taken together may represent a fused benzene ring, a substituted fused benzene ring, a trimethylene group, etc.; and p, q, r, and s each is 0 to 5, provided that p+q and r+s each is in the range of from 0 to 5); a palladium-phosphine catalyst obtained by causing a palladium compound to act on the novel 2,2-(diaryl)vinylphosphine compound; and a process for obtaining an arylamine, a diaryl and an arylalkyne in the presence of the palladium-phosphine catalyst.
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- A search for unambiguous vinylic SRN1 reactions
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In a search for unambiguous examples of the vinylic SRN1 route, vinyl bromides Ph(CH3)C=CHBr (10), Ph2C=CHBr (15), An2C=C(Br)An (18) and An2C=CBr2 (20) were treated with Me3CCOCH2- under photostimulation conditions in Me2SO, whereas substrates PhCH=CHBr (2), Ph2C=C(Br)Ph (3), 10 and 15 were similarly allowed to react with PhS- and PhCH2S-. With the strongly basic enolate ion, the prevailing reactions were elimination/addition routes, α-deprotonation followed by 1,2-Ph shift and bromide ion elimination, or halophilic steps. With 18, however, an SRN1 route was obtained. The weakly basic but reducing anion PhS- gave the SRN1 route with 2, 3 and 15. The nucleophilic character of the PhCH2S- anion instead prevailed with 15, whereas with 3 a variety of behaviours was obtained. The mechanistic interpretations were supported by the electrochemically determined redox potentials of the substrates. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Annunziata, Alfonso,Galli, Carlo,Gentili, Patrizia,Guarnieri, Alessandra,Beit-Yannai, Michal,Rappoport, Zvi
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p. 2136 - 2143
(2007/10/03)
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- Efficient mono- and dilithiation of 2-bromo-1,1-diphenylethene with n-butyllithium/tetramethylethylenediamine
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Lithiation of 2-bromo-1,1-diphenylethene (2) with n-butyllithium or tert-butyllithium/tetramethylethylenediamine (TMEDA) in pentane at -100°C effects a halogen-lithium exchange to give 2-lithio-1,1-diphenylethene (3) exclusively, which reacts with electrophiles to provide 2-substituted-1,1-diphenylethenes 5-8 in high yields. Further lithiation of the monolithium derivative 3 with n-butyllithium/TMEDA results in the direct ortho-lithiation of Z-located phenyl ring to give dilithium derivative 9, which forms disubstituted ethenes 11-13 or heterocycles 15-17 on treatment with electrophiles, tert-Butyllithium/TMEDA is ineffective for the second lithiation step.
- Korneev, Sergei M.,Kaufmann, Dieter E.
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p. 491 - 496
(2007/10/03)
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- 2,2 (Diarlyl) Vinylphosphine compound, palladium catalyst thereof, and process for producing arylamine, diaryl, or arylalkyne with the catalyst
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A novel 2,2-(diaryl)vinylphosphine compound represented by the following general formula (1): (wherein R1 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 5 to 7 carbon atoms, etc.; R2, R3, R4, R5, R6, and R7 may be the same or different and each is an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 5 to 7 carbon atoms, etc., provided that R4 and R5 taken together and/or R6 and R7 taken together may represent a fused benzene ring, a substituted fused benzene ring, a trimethylene group, etc.; and p, q, r, and s each is 0 to 5, provided that p+q and r+s each is in the range of from 0 to 5); a palladium-phosphine catalyst obtained by causing a palladium compound to act on the novel 2,2-(diaryl)vinylphosphine compound; and a process for obtaining an arylamine, a diaryl and an arylalkyne in the presence of the palladium-phosphine catalyst.
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- Stereoselective synthesis of (E)-β-arylvinyl halides by microwave-induced Hunsdiecker reaction
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(E)-β-Arylvinyl halides were prepared in high yields in a short reaction (1-2 min) by microwave irradiation of the corresponding 3-arylpropenoic acids in the presence of N-halosuccinimide and catalytic LiOAc.
- Kuang,Senboku,Tokuda
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p. 1439 - 1442
(2007/10/03)
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- Dehydrohalogenation of haloalkanes promoted by metal halides. Hydrogen halometalates formation and their use as hydrohalogenating agents
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In the dehydrohalogenation of 1,2-dihalo-1,1-diphenylethanes, 1, to 2- halo-1,1-diphenylethene, 2, either at 76°C or at 50°C, promoted by catalytic amount of the anhydrous bromides of Fe(III), Ru(III) and Al(III) and Fe(III) chloride the chemical transformation of the metal halides was observed. In reactions carried out in vacuum or under nitrogen atmosphere, the hydrogen halide eliminated from the organic substrate reacted with the metal halides rendering the unstable hydrogen perhalometalates H+(a)[MX(2+a)]a-. We demonstrate that these compounds behave as hydrogen halide donors in hydrohalogenation of olefins at 4°C.
- Suarez, Angela R.,Martin,, Sandra E.,Martinelli, Marisa,Domine, Marcelo E.,Mazzieri, Maria R.
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p. 7375 - 7386
(2007/10/03)
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- The Preparation and Lithiation of 3,3-Diphenyl-1,1,2-tribromocyclopropane
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3,3-Diphenyl-1,1,2-tribromocyclopropane 4 was synthesized from benzophenone in three steps in an overall yield of 11.4percent.Treatment of 4 with buthyllithium in THF at low temperatures, generated 1-lithio- and 1,2-dilithiocyclopropenes which were charac
- Li, Gang,Warner, Philip M.
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p. 8573 - 8576
(2007/10/02)
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- Generation of magnesium alkylidene carbenoids from 1-halovinyl sulfoxides with Grignard reagent - Their property and some synthetic uses
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The first example of magnesium alkylidene carbenoids is described. 1-Halovinyl sulfoxides 3 (X = F, Cl, Br) were synthesized from ketones and aryl halomethyl sulfoxides in three steps in moderate to good overall yields. Ligand exchange reaction of the sulfoxides of 3 with ethylmagnesium halide in THF at low temperature afforded a magnesium alkylidene carbenoid, which reacted with several electrophiles to give new alkylidene compounds.
- Satoh,Takano,Someya,Matsuda
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p. 7097 - 7100
(2007/10/02)
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- Dehydrobromination of 1,1-diaryl-1,2-dibromoalkanes catalyzed by iron and iron bromides. An ion-pair-mediated reaction?
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The participation of ion-paired Lewis acid/Lewis base in the dehydrohalogenations of 1,2-dibromo-1,1-diarylalkanes catalyzed by Fe0 and by Fe(II) and Fe(III) bromides was investigated.The reactivities of the catalyst employed were correlated with their chemical hardness.The influence of para substituents on the phenyl rins of the substrates and the results obtained in Lewis-acid-catalyzed and thermal dehydrobromination of the same compounds were compared.The experimental results could not be explained in terms of a Lewis-acid-catalyzed dehydrobromination.Key words: dehydrohalogenation, bromoalkanes, Lewis acid catalysts, ion-pair mechanism.
- Suarez, Angela R.,Suarez, Alejandra G.,Martin, Sandra E.,Mazzieri, Maria R.
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- The effect of polymer-supported reagent structure on bromination of organic molecules
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Crosslinked poly(styrene-co-4-vinylpyridine) reacted with hydrogen bromide or various alkyl bromides to pyridinium salts, which were further converted with chlorine to polymer supported reagents (1) containing up to 34% of chlorine, while substantial loss
- Zajc, Barbara,Zupan, Marko
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p. 6161 - 6166
(2007/10/02)
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- Reaction of Benzeneseleninyl Chloride with Olefins in the Presence of a Lewis Acid. A Novel One Step Vinylic Chlorination
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In the presence of aluminum chloride benzeneseleninyl chloride was found to be an exellent vinylic chlorinating reagent of olefins under mild conditions.However, such olefins as styrene, trans-stilbene, and trans-1-phenylpropene afforded dichloro adducts under similar conditions.A plausible reaction mechanism involving positive chlorine intermediate is proposed.
- Kamigata, Nobumasa,Satoh, Takeshi,Yoshida, Masato
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p. 449 - 454
(2007/10/02)
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- Indirect Electrochemical Reduction of Vinyl Halides and Related Compounds
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Some substituted vinyl halides and related compounds have been reduced indirectly by electrolysis using anion radicals as mediators.The rate of electron transfer from the electron donors to the electron acceptors has been measured by cyclic voltammetry, and the solvent and bond reorganization energy, λ, has been extracted from the data using the Marcus equation.The λ values for the vinyl and cyclopropyl halides were found to be closer to those for aryl halides than those for alkyl halides.The method was used preparatively for selective dehalogenation of vinyl halides, including derivatives of 10-bromo-5H-dibenzazepine.
- Gatti, Norberto,Jugelt, Werner,Lund, Henning
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p. 646 - 652
(2007/10/02)
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- Reaction of Olefins with Malonic Acid Derivatives in the Presence of Manganese(III) Acetate
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The reaction of methylmalonic acid with mono- and disubstituted olefins in the presence of manganese(III) acetate yielded 2-carboxy-2-methyl-4-butanolides in moderate to good yields.The reactions of bromomalonic acid and chloromalonic acid with a variety
- Fujimoto, Noriyuki,Nishino, Hiroshi,Kurosawa, Kazu
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p. 3161 - 3168
(2007/10/02)
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