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1. Synthesis of 2-phenyl-1,3-di(4-pyridyl)naphthvalene by photoinduced reversible valence isomerization of 2-phenyl-1,3-di(4-pyridyl)naphthalene

Author:
Li, Feng; Zhang, Shouliang; Hao, Haijun; Chen, Dongyue; Zhuang, Junpeng
Source:
Tetrahedron letters 2019 v.60 no.21 pp. 1416-1420
ISSN:
0040-4039
Subject:
chemical structure,   etc   ; isomerization; naphthalene;     Show all 3 Subjects
Abstract:
... 2-Phenyl-1,3-di(4-pyridyl)naphthvalene 3a was synthesized by the photoinduced reversible valence isomerization of 2-phenyl-1,3-di(4-pyridyl)naphthalene 2a. Then, 3a was converted into 3-phenyl-1,2-di(4-pyridyl)naphthalene 4a and 2a simultaneously. The t1/2 of 3a in DMSO-d6 at 90 °C was 2 h, while that at 110 °C was approximately 10 min. ...
DOI:
10.1016/j.tetlet.2019.04.036

2. Acyl furans from cyclohexane-1,3-diones – A synthesis of hibiscone C

Author:
Qu, Yang; Kraus, George A.
Source:
Tetrahedron letters 2019 v.60 no.17 pp. 1186-1188
ISSN:
0040-4039
Subject:
chemical structure,   etc   ; aromatization; furans;     Show all 3 Subjects
Abstract:
... A direct route to acyl furans was developed using dithiane anion addition followed by deprotection/aromatization. This led to an efficient synthesis of hibiscone C. ...
DOI:
10.1016/j.tetlet.2019.03.055

3. A new two-dimensional semiconducting carbon allotrope: A first-principles study

Author:
Wang, Shujie; Li, Jiagen; Zhu, Xi; Wang, Min
Source:
Carbon 2019 v.143 pp. 517-522
ISSN:
0008-6223
Subject:
chemical structure,   etc   ; graphene; semiconductors;     Show all 3 Subjects
Abstract:
... A new two-dimensional carbon allotrope, which consists of 18 atoms in a hexagonal cell, is theoretically investigated by performing first-principle method. The allotrope displays a P6/mmm symmetry (termed as hP-C18 carbon). The new 2D carbon phase has an sp2-sp3 network, consisting of hexagons and octagons formed by near-by atoms. The calculations demonstrate that hP-C18 carbon is a metastable 2D ...
DOI:
10.1016/j.carbon.2018.11.062

4. Stable High-Energy Excited States Observed in a Conjugated Molecule with Hindered Internal Conversion Processes

Author:
Jiang, Qinglin; Xu, Yuwei; Liang, Xiaoming; Wang, Cong; Tang, Xiaohui; Li, Ya; Qiu, Xu; Zheng, Nan; Zhao, Ruiyang; Zhao, Duokai; Hu, Dehua; Ma, Yuguang
Source:
Journal of physical chemistry 2019 v.123 no.10 pp. 6190-6196
ISSN:
1932-7455
Subject:
chemical structure,   etc   ; energy; photochemistry;     Show all 3 Subjects
Abstract:
... When the excited states of a molecule above its lowest excited state (Sₙ or Tₙ, n > 1) have a sufficient lifetime, photophysical and photochemical processes may occur directly in these high-energy levels, bypassing the Kasha’s rule and significantly influencing the system properties. Investigation of the relationship between molecular structure and intramolecular electronic relaxation processes ta ...
DOI:
10.1021/acs.jpcc.8b12544

5. First synthesis and further derivatization of furo[3,2-c]pyrazol-6-ones

Author:
Jacob, Clément; Lamberth, Clemens
Source:
Tetrahedron letters 2019 v.60 no.7 pp. 530-533
ISSN:
0040-4039
Subject:
chemical structure,   etc   ; derivatization; pyrazoles;     Show all 3 Subjects
Abstract:
... For the very first time furo[3,2-c]pyrazoles have been prepared starting from pyrazole building blocks instead from furanes. During this synthesis effort two previously unknown heterocyclic scaffolds have been discovered, the furo[3,2-c]pyrazol-6-ones and the 2-cyano-3-aminofuran-4-ones. ...
DOI:
10.1016/j.tetlet.2019.01.021

6. Total synthesis of natural (-)- and unnatural (+)-Melearoride A

Author:
Reed, Carson W.; Fulton, Mark G.; Nance, Kellie D.; Lindsley, Craig W.
Source:
Tetrahedron letters 2019
ISSN:
0040-4039
Subject:
chemical structure,   etc   ; alkylation; macrolides;     Show all 3 Subjects
Abstract:
... This communication details the first total synthesis of the 13-membered macrolide, (-)-Melearoride A, as well as unnatural (+)-Melearoride A. The synthesis features a concise 13 step synthesis (11 steps longest linear sequence) that offers flexible stereo-control and multiple opportunities for unnatural analog synthesis to delve into antifungal SAR. The route features a cuprate addition, an Evans ...
DOI:
10.1016/j.tetlet.2019.02.006

7. Accessing the decarboxylative allylation–divinylcyclopropane-cycloheptadiene rearrangement from the ketone/aldehyde substrate pool

Author:
Schroeder, Richard; Grenning, Alexander J.
Source:
Tetrahedron 2019 v.75 no.24 pp. 3231-3238
ISSN:
0040-4020
Subject:
chemical structure,   etc   ; chemical reactions; ketones;     Show all 3 Subjects
Abstract:
... Herein reported is access to allyl γ-butyrolactones and caprolactones that can undergo decarboxylative allylation/divinylcyclopropane–cycloheptadiene rearrangement. The overall sequence is brief (5 steps from commercial ketones/aldehydes) and yields diverse cycloheptadienes. The key decarboxylative allylation/divinylcyclopropane–cycloheptadiene rearrangement was unknown at the outset of our studie ...
DOI:
10.1016/j.tet.2019.03.036

8. Advances in 2H-azirine chemistry: A seven-year update

Author:
Khlebnikov, Alexander F.; Novikov, Mikhail S.; Rostovskii, Nikolai V.
Source:
Tetrahedron 2019 v.75 no.18 pp. 2555-2624
ISSN:
0040-4020
Subject:
chemical structure,   etc   ; azirines; chemical reactions;     Show all 3 Subjects
Abstract:
... 2H-Azirines are versatile building blocks for the preparation of various nitrogen-containing heterocycles. Seven years ago the comprehensive review on azirine chemistry was published in Tetrahedron. Since then, there had been an explosion of research activities in the field of these strained molecules. This renaissance is primarily associated with the discovery of new reactivity of azirines and in ...
DOI:
10.1016/j.tet.2019.03.040

9. New approach to unsymmetrical 1,3-diazatriphenylenes through intramolecular oxidative cyclodehydrogenation

Author:
Verbitskiy, Egor V.; Eltsov, Oleg S.; Zhilina, Ekaterina F.; Pakhomov, Ilya M.; Rusinov, Gennady L.; Chupakhin, Oleg N.; Charushin, Valery N.
Source:
Tetrahedron 2019 v.75 no.18 pp. 2687-2696
ISSN:
0040-4020
Subject:
chemical structure,   etc   ; chemical reactions; pyrimidines;     Show all 3 Subjects
Abstract:
... An efficient synthetic route towards previously inaccessible dibenzo[f,h]quinazolines and [1]benzothieno[3,2-f]benzo[h]quinazolines through FeCl3-mediated intramolecular oxidative cyclodehydrogenation of readily available 5-([1,1′-biphenyl]-2-yl)pyrimidines and 5-(2-phenylbenzo[b]thiophen-3-yl)pyrimidines is described. Molecular orbital calculations (DFT), as well as redox and photophysical measur ...
DOI:
10.1016/j.tet.2019.03.044

10. Retraction Note to: Mechanical properties and electronic structures of compressed C60, C180 and C60@C180 fullerene molecules

Author:
Shen, Haijun
Source:
Journal of materials science 2019 v.54 no.10 pp. 8058
ISSN:
0022-2461
Subject:
chemical structure,   etc   ; fullerene; mechanical properties;     Show all 3 Subjects
Abstract:
... The Editor-in-Chief has retracted this article [1] because it has been previously published by the same author in a Chinese-language journal [2]. The Chinese-language version was not cited in the duplicate publication and also it had a second author, XC Mu, who was not included in this article. The author apologizes for any inconvenience caused. The author agreed to this retraction. ...
DOI:
10.1007/s10853-019-03409-8

11. Synthesis and characterization of 2-(4-aryl-3-cyano-6-methylpyridin-2(1H)-ylidene)malononitriles

Author:
Bardasov, Ivan N.; Alekseeva, Anastasiya U.; Chunikhin, Sergey S.; Shishlikova, Maria A.; Ershov, Oleg V.
Source:
Tetrahedron letters 2019 v.60 no.17 pp. 1170-1173
ISSN:
0040-4039
Subject:
chemical structure,   etc   ; electrochemistry; oxidation; pyridines;     Show all 4 Subjects
Abstract:
... The synthesis of pyridine derivatives containing a buta-1,3-diene-1,1,3-tricarbonitrile fragment via the base-promoted reaction of benzalacetones and malononitrile dimer with subsequent oxidation is described. The influence of the substituents on the spectral-luminescent and electrochemical properties was also investigated. ...
DOI:
10.1016/j.tetlet.2019.03.054

12. Synthetic approaches to natural products containing 2,3-dihydrobenzofuran skeleton

Author:
Chen, Zhuang; Pitchakuntla, Mallesham; Jia, Yanxing
Source:
Natural product reports 2019 v.36 no.4 pp. 666-690
ISSN:
1460-4752
Subject:
chemical structure,   etc   ; furans; resveratrol; synthesis;     Show all 4 Subjects
Abstract:
... Covering: 2000 to 2018 Natural products containing the 2,3-dihydrobenzofuran (2,3-DHB) skeleton have been the focus of a substantial number of synthetic studies since 2000. Herein, we review the total syntheses of decursivine, serotobenine, lithospermic acid, linderol A, bisabosqual A, pterocarpans, conocarpan, heliannuols, and some resveratrol oligomers, with emphasis on the synthetic strategies ...
DOI:
10.1039/c8np00072g

13. DBU-promoted tandem Michael-addition/cyclization for the synthesis of polysubstituted pyrroles

Author:
Yang, Tianyu; Wang, Ke-Hu; Huang, Danfeng; Li, Pengfei; Deng, Zhoubin; Su, Yinpeng; Hu, Yulai
Source:
Tetrahedron 2019 v.75 no.15 pp. 2291-2297
ISSN:
0040-4020
Subject:
chemical structure,   etc   ; chemical reactions; pyrroles;     Show all 3 Subjects
Abstract:
... An efficient and transition-metal-free method for the synthesis of the structurally diversified pyrroles is described. Various α,β-unsaturated ynones reacted with N-substituted ethyl glycine ethyl ester hydrochlorides in the presence of DBU to form the corresponding products in good yields. This protocol has the advantages of readily available starting materials, mild reaction conditions and a wid ...
DOI:
10.1016/j.tet.2019.02.057

14. A convenient synthetic approach to dioncoquinone B and related compounds

Author:
Khmelevskaya, Ekaterina A.; Pelageev, Dmitry N.
Source:
Tetrahedron letters 2019 v.60 no.15 pp. 1022-1024
ISSN:
0040-4039
Subject:
chemical structure,   etc   ; chemical reactions; quinones;     Show all 3 Subjects
Abstract:
... A total synthesis of dioncoquinone B and related compounds, including ancistroquinones B, C and malvon A, is presented. The strategy is based on available reagents and can be used as a preparative synthesis of a number of natural and synthetic biologically active (3-alkyl)-2,7,8-di(tri)methoxy(hydroxy)-1,4-naphthoquinones. ...
DOI:
10.1016/j.tetlet.2019.03.016

15. A Method for Bischler–Napieralski-Type Synthesis of 3,4-Dihydroisoquinolines

Author:
Min, Lin; Yang, Weiguang; Weng, Yunxiang; Zheng, Weiping; Wang, Xinyan; Hu, Yuefei
Source:
Organic letters 2019 v.21 no.8 pp. 2574-2577
ISSN:
1523-7052
Subject:
chemical structure,   etc   ; chemical reactions; nitriles;     Show all 3 Subjects
Abstract:
... A new method for the Bischler–Napieralski-type synthesis of 3,4-dihydroisoquinolines was developed by a Tf₂O-promoted tandem annulation from phenylethanols and nitriles. Its success was mainly due to the fact that a phenonium ion was formed in the process and practically functioned as a stable and reactive primary phenylethyl carbocation. ...
DOI:
10.1021/acs.orglett.9b00534

16. Cesium-Carbonate-Mediated Benzalation of Substituted 2-Aryl-3-nitro-2H-chromenes with Substituted 4-Benzylidene-2-phenyloxazol-5(4H)-ones

Author:
Dai, Chenlu; Luo, Naili; Wang, Shan; Wang, Cunde
Source:
Organic letters 2019 v.21 no.8 pp. 2828-2832
ISSN:
1523-7052
Subject:
chemical structure,   etc   ; chemical reactions; oximes;     Show all 3 Subjects
Abstract:
... Cs₂CO₃-mediated domino benzalation reaction with a variety of 2-aryl-3-nitro-2H-chromenes and 4-benzylidene-2-phenyloxazol-5(4H)-ones has been realized. The reaction proceeds smoothly with a broad substrate scope, thus providing a variety of substituted (Z)-4-((Z)-benzylidene)chroman-3-one oximes in moderate to high yields, which were easily transformed into biologically important 4H-chromeno[3,4- ...
DOI:
10.1021/acs.orglett.9b00776

17. [4 + 1 + 1] Annulations of α-Bromo Carbonyls and 1-Azadienes toward Fused Benzoazaheterocycles

Author:
Zeng, Rong; Shan, Changyu; Liu, Ming; Jiang, Kun; Ye, Ying; Liu, Tian-Yu; Chen, Ying-Chun
Source:
Organic letters 2019 v.21 no.7 pp. 2312-2316
ISSN:
1523-7052
Subject:
chemical structure,   etc   ; cyclization reactions; pyridines;     Show all 3 Subjects
Abstract:
... An unexpected [4 + 1 + 1] annulation between α-bromo carbonyls and 1-azadienes, derived from 2-methylenebenzofuran-3(2H)-ones or 2-methylenebenzo[b]thiophene-3(2H)-ones, has been observed in the presence of DABCO and Cs₂CO₃. These reactions stand in contrast to the common [4 + 1] cyclization reactions of azadienes with the related sulfonium ylides. A range of fused benzofuro[3,2-b]pyridines and be ...
DOI:
10.1021/acs.orglett.9b00598

18. Copper-Catalyzed Radical Selenodifluoromethylation of Alkenes: Access to CF₂-Containing γ-Lactams

Author:
Sun, Kai; Wang, Songnan; Feng, Ranran; Zhang, Yixiao; Wang, Xin; Zhang, Zhiguo; Zhang, Bing
Source:
Organic letters 2019 v.21 no.7 pp. 2052-2055
ISSN:
1523-7052
Subject:
chemical structure,   etc   ; alkenes; derivatization; selenium;     Show all 4 Subjects
Abstract:
... Herein, a practical Cu-catalyzed selenodifluoromethylation protocol was developed, using readily available diselenides as the selenium source under external-oxidant-free conditions. Various structurally diverse 4-seleno-substituted α,α-difluoro-γ-lactams were obtained in moderate to excellent yields. Easy scaleup and the potential for product derivatization make this method attractive for the prep ...
DOI:
10.1021/acs.orglett.9b00240

19. Cascade reaction including a formal [5 + 2] cycloaddition by use of alkyne-Co2(CO)6 complex

Author:
Sakata, Yuki; Yasui, Eiko; Mizukami, Megumi; Nagumo, Shinji
Source:
Tetrahedron letters 2019 v.60 no.11 pp. 755-759
ISSN:
0040-4039
Subject:
chemical structure,   etc   ; alcohols; cycloaddition reactions;     Show all 3 Subjects
Abstract:
... A new cascade reaction including formal [5 + 2] cycloaddition was developed. Treatment of homocinnamyl alcohol and Co2(CO)6-complexed arylpropynal with BF3·OEt2 resulted in the generation of hydrobenzocycloheptafuran having an alkyne-Co2(CO)6 complex. The reaction consists of 5-membered ring selective Prins cyclization and subsequent Friedel-Crafts cyclization. The cascade reaction was applied to ...
DOI:
10.1016/j.tetlet.2019.01.045

20. Reaction of N-methylazomethine ylide with aroyl azides: Synthesis of imidazolidin-4-ones

Author:
Buev, Evgeny M.; Moshkin, Vladimir S.; Sosnovskikh, Vyacheslav Y.
Source:
Tetrahedron letters 2019 v.60 no.11 pp. 773-776
ISSN:
0040-4039
Subject:
chemical structure,   etc   ; azides; chemical reactions;     Show all 3 Subjects
Abstract:
... Aryl isocyanates generated in situ from aroyl azides react with N-methylazomethine ylide generated in situ from N-methylspiroanthraceneoxazolidine at 210 °C in a microwave reactor to form 3-arylimidazolidin-4-ones in 30–81% yield. ...
DOI:
10.1016/j.tetlet.2019.02.010