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You searched for: Journal Tetrahedron letters Remove constraint Journal: Tetrahedron letters Publication Year 2018 Remove constraint Publication Year: 2018 Source 2018 v.59 no.12 Remove constraint Source: 2018 v.59 no.12
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1. A new cyano-substituted fluorescamine superior to its original form as a fluorescent probe for amino acid detection

Author:
Motoyoshiya, Jiro; Tomioka, Satoshi; Kobayashi, Daigo; Fujimoto, Tetsuya
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1104-1107
ISSN:
0040-4039
Subject:
amino acids; chemical reactions; chemiluminescence; fluorescence; fluorescent dyes; moieties; organic compounds; spectral analysis
Abstract:
... Synthesis and spectral study of two new cyano-substituted fluorescamine as the fluorescent probes for amino acid detection have been carried out comparing with the original fluorescamine. Of the three compounds, the derivative with a cyano group at the meta-position on the 4-phenyl group was found to be superior to the original one in the reactivity toward some amino acids as well as the fluoresce ...
DOI:
10.1016/j.tetlet.2018.02.011

2. An oxidative cyclization reaction based fluorescent “Turn-On” probe for highly selective and rapid detection of hypochlorous acid

Author:
Chen, Bo; Fu, Hongyu; Lv, Yaohong; Li, Xin; Han, Yifeng
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1116-1120
ISSN:
0040-4039
Subject:
chemical structure; cyclization reactions; fluorescence; organic compounds; rapid methods
Abstract:
... A novel fluorescent turn-on probe, PHC1, for the detection of hypochlorous acid has been developed based on hypochlorous acid-initiated oxidative intramolecular cyclization. Endowed by the fast reaction rate, PHC1 features rapid detection kinetics, as well as high degree of selectivity and sensitivity for HClO. ...
DOI:
10.1016/j.tetlet.2018.02.018

3. Base metal-catalyzed alcohol C–C couplings under hydrogen transfer conditions

Author:
Cai, Yuan; Li, Feng; Li, Yu-Qing; Zhang, Wu-Bin; Liu, Feng-Hua; Shi, Shi-Liang
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1073-1079
ISSN:
0040-4039
Subject:
alcohols; catalysts; chemical bonding; chemical reactions; chemical structure; green chemistry; hydrogen; oxidants; reducing agents
Abstract:
... Comparing to classical Grignard-type carbonyl additions, transfer hydrogenative C–C bond-forming reactions using alcohols as carbonyl precursors have shown remarkable advantages from the perspective of atom economy, step economy and redox economy. The significant drawbacks of conventional method, such as the use of multi-step reactions, the premetalated reagents, and stoichiometric oxidants and re ...
DOI:
10.1016/j.tetlet.2018.01.077

4. Copper-catalyzed intermolecular aminochlorination of alkenes

Author:
Arteaga, Gean C.; Saavedra-Olavarría, Jorge; Almendras, Sebastián; Hermosilla-Ibáñez, Patricio; Almodovar, Iriux; Pérez, Edwin G.
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1091-1093
ISSN:
0040-4039
Subject:
alkenes; chemical reactions; chemical structure; chlorine; nitrogen; regioselectivity
Abstract:
... A copper-catalyzed radical and regioselective aminochlorination of alkenes using N-fluoro-benzenesulfonimide (NFSI) and TMSCl as nitrogen and chlorine sources respectively is reported. ...
DOI:
10.1016/j.tetlet.2018.02.010

5. Development of a new fluorescence ratiometric switch for endogenous hypochlorite detection in monocytes of diabetic subjects by dye release method

Author:
Das, Sangita; Aich, Krishnendu; Patra, Lakshman; Ghoshal, Kakali; Gharami, Saswati; Bhattacharyya, Maitree; Mondal, Tapan Kumar
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1130-1135
ISSN:
0040-4039
Subject:
cardiovascular diseases; chemical reactions; chemical structure; fluorescence; fluorescent dyes; health hazards; humans; hyperlipidemia; monocytes; noninsulin-dependent diabetes mellitus; organic compounds; oxidative stress
Abstract:
... Increased oxidative stress in metabolic complications like type 2 diabetes, dyslipidemia and cardiovascular disorders exerts potential health hazards in many facets. Enhanced production of reactive oxygen species (ROS) due to increased oxidative stress promotes the damage of many biologically important macromolecules. Hypochlorous acid (HOCl), a microbicidal agent is also known to be an important ...
DOI:
10.1016/j.tetlet.2018.02.023

6. Direct synthesis of α-thio aromatic acids from aromatic amino acids

Author:
Samuels, Eric R.; Sevrioukova, Irina F.
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1140-1142
ISSN:
0040-4039
Subject:
Lewis bases; amino acids; aromatic acids; bromination; chemical structure; sodium; thiols
Abstract:
... Modified amino acids are useful synthetic components in both chemistry and biology. Here we describe a simple, scalable two-step procedure to generate α-thio aromatic acids from aromatic amino acids with yields of up to 96%. Diazotization and α-lactone mediated bromination efficiently form the α-bromo acid with retention of configuration. Thiol substitution with mild reagents such as sodium hydros ...
DOI:
10.1016/j.tetlet.2018.02.030
PubMed:
30140110
PubMed Central:
PMC6101259

7. First example of the cascade acylation/IMDAV/ene reaction sequence, leading to N-arylbenzo[f]isoindole-4-carboxylic acids possessing anti-viral activity

Author:
Voronov, Alexander A.; Alekseeva, Kseniia A.; Ryzhkova, Elena A.; Zarubaev, Vladimir V.; Galochkina, Anastasia V.; Zaytsev, Vladimir P.; Majik, Mahesh S.; Tilve, Santosh G.; Gurbanov, Atash V.; Zubkov, Fedor I.
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1108-1111
ISSN:
0040-4039
Subject:
acylation; antiviral properties; carboxylic acids; chemical structure; maleic anhydrides
Abstract:
... The reaction between readily accessible N-aryl-3-phenylallylamines and maleic anhydride led to unexpected products – polysubstituted hydrogenated benzo[f]isoindole-4-carboxylic acids. This transformation proceeds through a previously unknown sequence of steps: N-acylation of the allylamine with maleic anhydride, intramolecular Diels-Alder reaction of the vinylarene in the intermediate N-maleamide, ...
DOI:
10.1016/j.tetlet.2018.02.015

8. First total synthesis of the anti-inflammatory and pro-resolving lipid mediator 16(R),17(S)-diHDHA

Author:
Rodriguez, Ana R.; Spur, Bernd W.
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1143-1146
ISSN:
0040-4039
Subject:
chemical structure; docosahexaenoic acid; enzymatic reactions; epoxidation reactions; hydrolysis; isomerization; synthesis; vanadium
Abstract:
... The first total synthesis of the anti-inflammatory and pro-resolving lipid mediator 16(R),17(S)-diHDHA, derived from docosahexaenoic acid (DHA), and its 16-epimer have been achieved. Two synthetic approaches are described for the synthesis of 16(R),17(S)-diHDHA. The first strategy started from DHA and used an enzymatic reaction, a vanadium catalyzed allylic epoxidation and a base-promoted epoxide ...
DOI:
10.1016/j.tetlet.2018.02.029

9. Hafnium inspired activation of highly hindered anhydrides in the acylation of alcohols and polyols

Author:
Mensah, Enoch; Day, Aaron; Thomas, Raven
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1094-1098
ISSN:
0040-4039
Subject:
acylation; ambient temperature; anhydrides; catalysts; chemical structure; hafnium; methodology; polyols
Abstract:
... A novel and highly efficient method for activating highly hindered acid anhydrides towards the acylation of alcohols and carbohydrate-derived polyols has been developed. This new method relies on the capacity of the hafnium triflate catalyst Hf(OTf)2 to activate highly hindered acid anhydrides, and to direct the acylation reaction. This new acylation protocol is mild and proceed at room temperatur ...
DOI:
10.1016/j.tetlet.2018.02.009

10. Identification of novel sesterterpenes by genome mining of phytopathogenic fungi Phoma and Colletotrichum sp.

Author:
Gao, Lei; Narita, Koji; Ozaki, Taro; Kumakura, Naoyoshi; Gan, Pamela; Minami, Atsushi; Liu, Chengwei; Lei, Xiaoguang; Shirasu, Ken; Oikawa, Hideaki
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1136-1139
ISSN:
0040-4039
Subject:
Colletotrichum orbiculare; Phoma; Pleospora betae; biosynthesis; chemical structure; enzymes; genome mining; heterologous gene expression; multigene family; organic compounds; oxidation; plant pathogenic fungi
Abstract:
... Two homologous gene clusters for the biosynthesis of sesterterpenes betaestacins were identified from two phytopathogens, Phoma betae and Colletotrichum orbiculare. Heterologous expression of identified oxidation enzymes with previously-characterized PbTS1 (BtcAPb) resulted in the production of seven novel sesterterpenes. Although both strains possessed homologous enzymes, oxidation state of corre ...
DOI:
10.1016/j.tetlet.2018.02.022

11. Inexpensive and rapid hydrogenation catalyst from CuSO4/CoCl2 — Chemoselective reduction of alkenes and alkynes in the presence of benzyl protecting groups

Author:
Ficker, Mario; Svenningsen, Søren W.; Larribeau, Thomas; Christensen, Jørn B.
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1125-1129
ISSN:
0040-4039
Subject:
alkenes; alkynes; catalysts; chemical structure; chemoselectivity; copper sulfate; hydrogen; hydrogenation; sodium
Abstract:
... The simple reduction of a number of alkenes and alkynes was performed with a typical reaction time of 20 min using a copper-cobalt catalytic system. The reduction did not cleave benzyl protecting groups which are usually vulnerable to catalytic hydrogenation reactions. The catalyst can be prepared in situ by reduction of the inexpensive precursor salts CuSO4 and CoCl2 with NaBH4. Sodium borohydrid ...
DOI:
10.1016/j.tetlet.2018.02.026

12. Oxidation of thiazolo[3,2-a]pyrimidin-3(2H)-ones with DMSO and Lawesson’s reagent

Author:
Lashmanova, Eugenia A.; Kirdyashkina, Anastasiya I.; Slepukhin, Pavel A.; Shiryaev, Andrey K.
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1099-1103
ISSN:
0040-4039
Subject:
X-radiation; absorption; ambient temperature; chemical bonding; color; diastereomers; dimethyl sulfoxide; nuclear magnetic resonance spectroscopy; oxidation
Abstract:
... 2,2′-Dimers with a central double bond were prepared by the oxidation of 5,6-disubstituted 7-methyl-5H-[1,3]thiazolo[3,2-a]pyrimidin-3(2H)-ones with DMSO and Lawesson’s reagent at room temperature. The role of DMSO as an oxidizing reagent was confirmed by NMR spectroscopy. The E-configuration of the central CC bond for the two diastereomers of compound 8m was proven by single crystal X-ray data. T ...
DOI:
10.1016/j.tetlet.2018.02.014

13. Rhenium complex-catalyzed carbon-carbon formation of alcohols and organosilicon compounds

Author:
Umeda, Rui; Jikyo, Toshifumi; Toda, Kazuki; Osaka, Issey; Nishiyama, Yutaka
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1121-1124
ISSN:
0040-4039
Subject:
alcohols; alkenes; chemical reactions; chemical structure; esters; organosilicon compounds; rhenium
Abstract:
... The coupling reactions of allylic and benzylic alcohols and allyltrimethylsilane are efficiently catalyzed by a rhenium complex to give the corresponding 1,5-dienes and alkenes in moderate to good yields. Similarly, alcohols were coupled with ketene silyl acetals to form the corresponding esters. ...
DOI:
10.1016/j.tetlet.2018.02.019

14. Synthesis of (arylselanyl)- and (arylsulfenyl)-alkyl-1,2,3-triazolo-1,3,6-triazonines via a copper-catalyzed multicomponent reaction

Author:
Aquino, Thalita B.; do Nascimento, José Edmilson R.; Dias, Ítalo F.C.; de Oliveira, Daniela H.; Barcellos, Thiago; Lenardão, Eder J.; Perin, Gelson; Alves, Diego; Jacob, Raquel G.
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1080-1083
ISSN:
0040-4039
Subject:
alkynes; chemical reactions; chemical structure; copper; iodides; selenium
Abstract:
... An efficient copper-catalyzed multicomponent reaction was developed for the synthesis of (arylselanyl)- or (arylsulfenyl)-alkyl-1,2,3-triazolo-1,3,6-triazonines. The products were obtained in moderate to excellent yields via the reaction of o-phenylenediamine, 2-azidobenzaldehyde and different arylchalcogenyl alkynes using catalytic copper iodide in 1,4-dioxane at 100 °C. The reactions tolerated a ...
DOI:
10.1016/j.tetlet.2018.01.072

15. Tandem Prins cyclization for the synthesis of 1,8-dioxa-3-azaspiro[4.5]dec-2-ene derivatives

Author:
Reddy, L. Madhava; Reddy, V. Veerabadra; Satteyyanaidu, V.; Lakshmi, J.K.; Krishna Reddy, Ch.; Reddy, B.V. Subba
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1084-1086
ISSN:
0040-4039
Subject:
chemical reactions; chemical structure; copper; methylene chloride
Abstract:
... A tandem Prins strategy has been developed for the synthesis of 1,8-dioxa 3-azaspiro[4.5]dec-2-ene derivatives using 5 mol% Cu(OTf)2 in dichloromethane at 0 °C under mild reaction conditions in short reaction times. This method provides the products in good yields with a diverse substitution pattern. ...
DOI:
10.1016/j.tetlet.2018.01.075

16. Toward bioluminescence in the near-infrared region: Tuning the emission wavelength of firefly luciferin analogues by allyl substitution

Author:
Kitada, Nobuo; Saitoh, Tsuyoshi; Ikeda, Yuma; Iwano, Satoshi; Obata, Rika; Niwa, Haruki; Hirano, Takashi; Miyawaki, Atsushi; Suzuki, Koji; Nishiyama, Shigeru; Maki, Shojiro A.
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1087-1090
ISSN:
0040-4039
Subject:
Lampyridae; allylation; bioluminescence; chemical structure; luciferase; luciferin; organic compounds; wavelengths
Abstract:
... The synthesis and bioluminescence of allyl-substituted luciferin derivatives as substrates for firefly luciferase are reported. The allylation of luciferins induced bathochromic shift (15–40 nm) of the bioluminescence emission. Upon combination with other chemical modifications for bioluminescence wavelength tuning, novel red emitting luciferin analogues were obtained with emission maxima at 685 a ...
DOI:
10.1016/j.tetlet.2018.01.078

17. Understanding the tetrazole ring cleavage reaction with hydrazines: Structural determination and mechanistic insight

Author:
Shyyka, Olga Ya.; Pokhodylo, Nazariy T.; Slyvka, Yurii I.; Goreshnik, Evgeny A.; Obushak, Mykola D.
Source:
Tetrahedron letters 2018 v.59 no.12 pp. 1112-1115
ISSN:
0040-4039
Subject:
X-radiation; chemical reactions; chemical structure; hydrazines; nuclear magnetic resonance spectroscopy
Abstract:
... A distinction in the behaviour of several hydrazines as N-nucleophiles in the recently developed one-pot method for pyrimidine core annulation via 1H-tetrazole ring cleavage was examined. The product structures, 2,3-diamino- or hydrazino derivatives of thieno[3,2-d]pyrimidin-4(3H)-ones, thieno[2,3-d]pyrimidin-4(3H)-ones and [1]benzofuro[3,2-d]pyrimidin-4(3H)-one, were elucidated based on NMR and s ...
DOI:
10.1016/j.tetlet.2018.02.016