771-14-2Relevant articles and documents
Catalyst-Free 1,2-Dibromination of Alkenes Using 1,3-Dibromo-5,5-dimethylhydantoin (DBDMH) as a Bromine Source
Wang, Lei,Zhai, Lele,Chen, Jinyan,Gong, Yulin,Wang, Peng,Li, Huilin,She, Xuegong
supporting information, p. 3177 - 3183 (2022/02/23)
A direct 1,2-dibromination method of alkenes is realized using 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) as a bromine source. This reaction proceeds under mild reaction conditions without the use of a catalyst and an external oxidant. Various sorts of alkene substrates are transformed into the corresponding 1,2-dibrominated products in good to excellent yields with broad substrate scope and exclusive diastereoselectivity. This method offers a green and practical approach to synthesize vicinal dibromide compounds.
Atroposelective Synthesis, Structure and Properties of a Novel Class of Axially Chiral N-Aryl Quinolinium Salt
Sweet, Jamie S.,Rajkumar, Sundaram,Dingwall, Paul,Knipe, Peter C.
supporting information, p. 3980 - 3985 (2021/03/31)
Inspired by naturally occurring molecules containing atropisomeric N+-C axes, we have developed a novel synthetic approach to generate a library of axially chiral N-aryl quinolinium salts. Enantiopurities up to 93 % ee were obtained via a four-step route from commercially available precursors. Axial stereochemistry was controlled through an enantioselective ring-closing Buchwald–Hartwig coupling reaction. The structure and properties of the salts were examined by X-ray crystallography, DFT, UV-Vis, and fluorescence spectroscopy, revealing high rotational barriers and solvatochromic behaviour.
Compound for organic photoelectric device Composition for organic photoelectric device, organic photoelectric device, and display device
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Paragraph 0225-0229, (2021/10/13)
A compound for an organic optoelectronic device, a composition for an organic optoelectronic device including the same, an organic optoelectronic device, and a display device, the compound being represented by a combination of Chemical Formula 1 and Chemical Formula 2:
Mild and Selective Method of Bromination of Flavonoids
Hurtová, Martina,Biedermann, David,Kuzma, Marek,K?en, Vladimír
, p. 3324 - 3331 (2020/11/30)
A new method was developed for the mild and selective bromination of simple aromatic compounds and flavonoids in good yields using α,β-dibromohydrocinnamic acid in the presence of a base. This procedure enables selective mono- or dibromination of compounds highly sensitive to oxidative or radical attack. New brominated derivatives of silymarin flavonolignans and related flavonoids were prepared. These brominated derivatives can be used as valuable synthetic intermediates in further synthesis.
Making endo-cyclizations favorable again: A conceptually new synthetic approach to benzotriazoles via azide group directed lithiation/cyclization of 2-azidoaryl bromides
Ageshina, Alexandra A.,Chesnokov, Gleb A.,Topchiy, Maxim A.,Alabugin, Igor V.,Nechaev, Mikhail S.,Asachenko, Andrey F.
supporting information, p. 4523 - 4534 (2019/05/17)
Although benzotriazoles are important and ubiquitous, currently there is only one conceptual approach to their synthesis: bridging the two ortho-amino groups with an electrophilic nitrogen atom. Herein, we disclose a new practical alternative-the endo-cyclization of 2-azidoaryl lithiums obtained in situ from 2-azido-aryl bromides. The scope of the reaction is illustrated using twenty-four examples with a variety of alkyl, alkoxy, perfluoroalkyl, and halogen substituents. We found that the directing effect of the azide group allows selective metal-halogen exchange in aryl azides containing several bromine atoms. Furthermore, (2-bromophenyl)diazomethane undergoes similar cyclization to give an indazole. Thus, cyclizations of aryl lithiums containing an ortho-X = Y = Z group emerge as a new general approach for the synthesis of aromatic heterocycles. DFT computations suggested that the observed endo-selectivity applies to the anionic cyclizations of other functionalities that undergo "1,1-additions" (i.e., azides, diazo compounds, and isonitriles). In contrast, cyclizations with the heteroatomic functionalities that follow the "1,2-addition" pattern (cyanates, thiocyanates, isocyanates, isothiocyanates, and nitriles) prefer the exo-cyclization path. Hence, such reactions expand the current understanding of stereoelectronic factors in anionic cyclizations.
Synthesis, kinetics, and mechanism of bromophenols by N-bromophthalimide in aqueous acetic acid
Anjaiah, Birla,Prameela, Kethavath,Srinivas, Pabba,Rajanna, Kamatala Chinna
, p. 804 - 812 (2018/09/11)
The kinetics and mechanism of bromination of phenol and its substituents, viz. 4-chlorophenol, 4-bromophenol, 4-methylphenol, and 4-methoxyphenol by N-bromophthalimide (NBP) in the presence of mercuric acetate in the temperature range of 303–318?K in aqueous acetic acid medium have been investigated. The reaction follows first-order dependence on [NBP] and fractional order dependence of rate on [Phenol]. The activation parameters have been evaluated, and based on the observed kinetic results the probable mechanism has been proposed. Observed kinetic features and Hammett's reaction constant (ρ) suggests that bromination occurs through electrophilic substitution of bromonium ion (Br+) into the aromatic ring in the transition state. Large negative entropy of activation values probably suggests the rigid nature of transition state.
Synthesis of indole-fused heteroacenes by cascade cyclisation involving rhodium(ii)-catalysed intramolecular C-H amination
Matsuda, Takanori,Ito, Hirotaka
supporting information, p. 6703 - 6707 (2018/09/29)
Heteroacenes are potentially important materials for organic electronics and their syntheses are of topical interest. Herein we report the development of a catalytic, redox-neutral reaction for the synthesis of the 5,10-dihydroindolo[3,2-b]indole class of
Molecular propellers that consist of dehydrobenzo[14]annulene blades
Nobusue, Shunpei,Mukai, Yuichi,Fukumoto, Yo,Umeda, Rui,Tahara, Kazukuni,Sonoda, Motohiro,Tobe, Yoshito
supporting information, p. 12814 - 12824,11 (2020/09/14)
A new class of propel- ler-shaped compound (4), which consisted of dehydrobenzo[14]annulene ([14]DBA) blades, as well as its naphtho homologues (5 and 6), have been prepared. Although NMR studies of compound 4 did not provide useful information regarding
Coarctate versus pericyclic reactivity in naphthalene-fused azo-ene-ynes: Synthesis of benzocinnolines and benzoisoindazoles
McClintock, Sean P.,Zakharov, Lev N.,Herges, Rainer,Haley, Michael M.
scheme or table, p. 6798 - 6806 (2011/08/06)
The cyclization reactions of naphthalene-fused azo-ene-yne compounds are explored both computationally and experimentally. Calculations reveal that naphtho-fusion to an azo- ene-yne scaffold does not significantly alter the transition state energies compared to the benzene-based systems; however, fusing the naphthalene in an angular fashion leads to lower energy intermediates due to the creation of arenes possessing greater aromaticity. Experimentally, the cyclization of the angular systems yields not only the expected monomeric benzocinnolines and benzoisoindazoles, but also several dimeric structures, including one that readily isomerizes in the presence of light and/or trace acid. Copyright
Lewis acid-promoted synthesis of unsymmetrical and highly functionalized carbazoles and dibenzofurans from biaryl triazenes: Application for the total synthesis of clausine C, clausine R, and clauraila A
Yang, Weijun,Zhou, Jun,Wang, Binjie,Ren, Hongjun
supporting information; scheme or table, p. 13665 - 13669 (2012/01/15)
A natural approach: A Lewis acid-promoted nucleophilic aromatic substitution approach to the regioselective synthesis of highly substituted carbazoles and dibenzofurans has been developed. The annulation process is applied to the total synthesis of carbazole alkaloids clausine C, clausine R, and clauraila A (see scheme).