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1. Metal–ligand cooperative transformation of alkyl azide to isocyanate occurring at a Co–Si moiety

Author:
So, Jongho; Kim, Seji; Cho, Kyung-Bin; Lee, Yunho
Source:
Chemical communications 2021 v.57 no.26 pp. 3219-3222
ISSN:
1364-548X
Subject:
moieties,   etc   ; azides; ligands; photolysis;     Show all 4 Subjects
Abstract:
... A cobalt-silyl moiety reveals metal–ligand cooperative group transfer to generate isocyanate from the reaction of alkyl azide and CO. This reaction involves the reversible insertion of a nitrene group into a Co–Si bond. Photolysis leads to ligand substitution of a Co(CO)₂ species, allowing the successful catalytic conversion of AdN₃ to AdNCO under CO(g). ...
DOI:
10.1039/d0cc08012h

2. Synthesis of 2,5-bis(spirocyclohexane)-substituted nitroxides: New spin labeling agents

Author:
Polienko, Yuliya F.; Kuprikova, Natalia M.; Parkhomenko, Dmitriy A.; Gatilov, Yuriy V.; Chernyak, Elena I.; Kirilyuk, Igor A.
Source:
Tetrahedron 2021 v.81 pp. 131915
ISSN:
0040-4020
Subject:
moieties,   etc   ; acetylene; synthesis;     Show all 3 Subjects
Abstract:
... The nitroxides with spirocyclic moieties adjacent to N–O group were shown to demonstrate longer spin echo dephasing times between 80 and 295 K than tetramethyl ones. New spin labels for site-directed spin labeling have been prepared from 2,5-bis(spirocyclohexane)-substituted nitroxides of pyrroline series. The labels synthesized contain terminal acetylene and iodoacetamide groups are analogous to ...
DOI:
10.1016/j.tet.2020.131915

3. Direct bromodeboronation of arylboronic acids with CuBr2 in water

Author:
Tang, Yan-Ling; Xia, Xian-Song; Gao, Jin-Chun; Li, Min-Xin; Mao, Ze-Wei
Source:
Tetrahedron letters 2021 v.64 pp. 152738
ISSN:
0040-4039
Subject:
moieties,   etc   ; acids; bromides; water;     Show all 4 Subjects
Abstract:
... An efficient and practical method has been developed for the preparation of aryl bromides via the direct bromodeboronation of arylboronic acids with CuBr₂ in water. This strategy provides several advantages, such as being ligand-free, base-free, high yielding, and functional group tolerant. ...
DOI:
10.1016/j.tetlet.2020.152738

4. Selective transformations of 2-(p-toluenesulfonyl)-N-tosylhydrazones to substituted 1,2,3-thiadiazoles

Author:
Feng, Yijiao; He, Jing; Li, Weiwei; Yang, Zhen; Wei, Yueting; Liu, Ping; Zhao, Jixing; Gu, Chengzhi; Wang, Wenli
Source:
Tetrahedron 2021 v.78 pp. 131803
ISSN:
0040-4020
Subject:
moieties,   etc   ; materials; protocols; sulfur;     Show all 4 Subjects
Abstract:
... Selective transformations of 2-(p-toluenesulfonyl)-N-tosylhydrazones with different sulfur sources have been established. A series of 4-aryl-1,2,3-thiadiazoles and novel 4-aryl-5-tosyl-1,2,3-thiadiazoles were selectively constructed by the adjustment of reaction conditions. These protocols feature short reaction time, good compatibility of functional group, easily available materials, and good sel ...
DOI:
10.1016/j.tet.2020.131803

5. Efficient access to 3′-O-phosphoramidite derivatives of tRNA related N⁶-threonylcarbamoyladenosine (t⁶A) and 2-methylthio-N⁶-threonylcarbamoyladenosine (ms²t⁶A)

Author:
Debiec, Katarzyna; Sochacka, Elzbieta
Source:
RSC advances 2021 v.11 no.4 pp. 1992-1999
ISSN:
2046-2069
Subject:
moieties,   etc   ; adenosine; ribose; synthesis;     Show all 4 Subjects
Abstract:
... An efficient method of ureido linkage formation during epimerization-free one-pot synthesis of protected hypermodified N⁶-threonylcarbamoyladenosine (t⁶A) and its 2-SMe analog (ms²t⁶A) was developed. The method is based on a Tf₂O-mediated direct conversion of the N-Boc-protecting group of N-Boc-threonine into the isocyanate derivative, followed by reaction with the N⁶exo-amine function of the suga ...
DOI:
10.1039/d0ra09803e

6. Rhodium-catalyzed direct C[sbnd]H amination of 2-arylindoles and 7-arylindoles with free amines

Author:
Qin, Yao; Zhuang, Weihui; Guo, Xiemin; Zhang, Xiaofeng; Huang, Qiufeng
Source:
Tetrahedron letters 2021 v.62 pp. 152686
ISSN:
0040-4039
Subject:
moieties,   etc   ; amination; amines; indoles;     Show all 4 Subjects
Abstract:
... Synthetically meaningful 2-(2′-amino)phenylindoles or 7-(2′-amino)phenylindoles were accessed by rhodium-catalyzed NH-indole-directed CH amination of 2-aryl-1H-indoles or 7-aryl-1H-indoles with free amines. This method is compatible with a wide variety of functional groups, thus enabling expedient access to fused-polycyclic frameworks containing indole units. ...
DOI:
10.1016/j.tetlet.2020.152686

7. Copper-catalyzed synthesis of 2-aminopyridylbenzoxazoles via domino reactions of intermolecular N-arylation and intramolecular O-arylation

Author:
Lu, Ju-You
Source:
RSC advances 2019 v.9 no.24 pp. 13414-13417
ISSN:
2046-2069
Subject:
moieties
Abstract:
... A simple and general approach to nitrogen-containing heterocycles via copper-catalyzed domino reaction has been developed, and the corresponding 2-aminopyridylbenzoxazole derivatives were obtained in good to excellent yields using the readily available starting materials. This method possesses unique step economy features, and is of high tolerance towards various functional groups in the substrate ...
DOI:
10.1039/c9ra01908a

8. Transient Imine as a Directing Group for the Metal-Free o-C–H Borylation of Benzaldehydes

Author:
Rej, Supriya; Chatani, Naoto
Source:
Journal of the American Chemical Society 2021 v.143 no.7 pp. 2920-2929
ISSN:
1520-5126
Subject:
moieties,   etc   ; benzaldehyde; imines; organic chemistry;     Show all 4 Subjects
Abstract:
... Organoboron reagents are important synthetic intermediates and have wide applications in synthetic organic chemistry. The selective borylation strategies that are currently in use largely rely on the use of transition-metal catalysts. Hence, identifying much milder conditions for transition-metal-free borylation would be highly desirable. We herein present a unified strategy for the selective C–H ...
DOI:
10.1021/jacs.0c13013

9. CO release from Mn(i)-based photoCORMs with single photons in the phototherapeutic region

Author:
Stenger-Smith, Jenny; Chakraborty, Indranil; Ouattara, Ramatoulaye; Sameera, W. M. C.; Rue, Kelly; Mascharak, Pradip
Source:
Chemical communications 2021 v.57 no.9 pp. 1101-1104
ISSN:
1364-548X
Subject:
moieties,   etc   ; hospitals; instrumentation; photons; phototherapy;     Show all 5 Subjects
Abstract:
... Both the instrumentation required for two photon excitation (TPE) and tissue damage possibility by high intensity laser lights could impede TPE-induced CO delivery in hospital settings. Herein we report two Mn(i)-based photoCORMs with a fac-{Mn(CO)₃} moiety that exhibit facile CO release upon simple exposure to light within the phototherapeutic region (no TPE required). ...
DOI:
10.1039/d0cc07405e

10. Generation of stereodefined (Z)-3,4-dihydronaphthalen-1(2H)-ones via copper-catalyzed annulation-cyanotrifluoromethylation of 1,7-enynes

Author:
Ji, Wen-Zhe; Shi, Hao-Nan; Hao, Wen-Juan; Wei, Ping; Tu, Shu-Jiang; Jiang, Bo
Source:
Tetrahedron letters 2021 v.64 pp. 152722
ISSN:
0040-4039
Subject:
moieties,   etc   ; carbon; protocols; stereoselectivity; yields;     Show all 5 Subjects
Abstract:
... A new three-component strategy for the copper-catalyzed annulation–cyanotrifluoromethylation of easily available 1,7-enynes with Togni’s reagent and TMSCN is developed. The reaction proceeds smoothly under mild conditions, providing a rapid and concise access to a wide range of stereodefined (Z)-3,4-dihydronaphthalen-1(2H)-ones with a quaternary carbon center in generally good yields. The protocol ...
DOI:
10.1016/j.tetlet.2020.152722

11. Reactivity of NHC/diphosphene-coordinated Au(i)-hydride

Author:
Dhara, Debabrata; Scheschkewitz, David; Chandrasekhar, Vadapalli; Yildiz, Cem B.; Jana, Anukul
Source:
Chemical communications 2021 v.57 no.6 pp. 809-812
ISSN:
1364-548X
Subject:
moieties,   etc   ; acetylene; carbenes; gold; nitrogen;     Show all 5 Subjects
Abstract:
... We report the reactivity of isolable Au(i)-hydride stabilized by an NHC-coordinated diphosphene towards substrates containing C–C and N–N multiple bonds (NHC = N-heterocyclcic carbene). Reactions with dimethyl acetylenedicarboxylate and azobenzene lead to a trans-addition of the Au(i)-H across the C–C triple bond and the N–N double bond, respectively. In contrast, the reaction with ethyl diazoacet ...
DOI:
10.1039/d0cc05461e

12. β-Cyclodextrin: a supramolecular catalyst for metal-free approach towards the synthesis of 2-amino-4,6-diphenylnicotinonitriles and 2,3-dihydroquinazolin-4(1H)-one

Author:
Mitra, Bijeta; Chandra Pariyar, Gyan; Ghosh, Pranab
Source:
RSC advances 2021 v.11 no.3 pp. 1271-1281
ISSN:
2046-2069
Subject:
moieties,   etc   ; catalysts; heterocyclic compounds; toxicity;     Show all 4 Subjects
Abstract:
... β-Cyclodextrin, a green and widespread supramolecular catalyst, has been explored as a highly proficient promoter for the metal-free one-pot multi-component synthesis of a vast range of highly functionalized bioactive heterocyclic moiety, 2-amino-4,6-diphenylnicotinonitriles and 2,3-dihydroquinazolin-4(1H)-one, from easily available precursor aldehydes. The main endeavor of these protocols is to e ...
DOI:
10.1039/d0ra09562a

13. Two decades of the synthesis of mono- and bis-aminomercapto[1,2,4]triazoles

Author:
Riyadh, Sayed M.; Gomha, Sobhi M.
Source:
RSC advances 2020 v.10 no.42 pp. 24994-25012
ISSN:
2046-2069
Subject:
moieties,   etc   ; triazoles;     Show all 2 Subject
Abstract:
... 4-Amino-5-mercapto[1,2,4]triazole and its 3-substituted derivatives have proven to be of biological interest and provide access to a new class of biologically active heterocyclic compounds for biomedical applications. This study will be helpful for scientific researchers interested in the chemistry of bifunctional versatile compounds as it provides a collection of all the methods for the preparati ...
DOI:
10.1039/d0ra04208k

14. Hybrids of cationic [4]helicene and N-heterocyclic carbene as ligands for complexes exhibiting (chir)optical properties in the far red spectral window

Author:
Tarrieu, Robert; Delgado, Irene Hernandez; Zinna, Francesco; Dorcet, Vincent; Colombel-Rouen, Sophie; Crévisy, Christophe; Baslé, Olivier; Bosson, Johann; Lacour, Jérôme
Source:
Chemical communications 2021 v.57 no.31 pp. 3793-3796
ISSN:
1364-548X
Subject:
moieties,   etc   ; carbenes; helicenes; heterocyclic nitrogen compounds; ligands;     Show all 5 Subjects
Abstract:
... Synthesis, electronic and structural properties of a chiral NHC bearing a N-bonded cationic [4]helicene moiety are reported. This ligand is used to construct Auᴵ, Auᴵᴵᴵ and Rhᴵ complexes exhibiting far-red (chir)optical properties regardless of the metal. ...
DOI:
10.1039/d1cc00898f

15. Acceptor-mediated regioselective enzyme catalyzed sialylation: chemoenzymatic synthesis of GAA-7 ganglioside glycan

Author:
Tseng, Hsin-Kai; Su, Yung-Yu; Chang, Ting-Wei; Liu, Hsin-Chien; Li, Pei-Jhen; Chiang, Pei-Yun; Lin, Chun-Cheng
Source:
Chemical communications 2021 v.57 no.28 pp. 3468-3471
ISSN:
1364-548X
Subject:
moieties,   etc   ; galactose; gangliosides; glycosyltransferases; regioselectivity; sialic acid;     Show all 6 Subjects
Abstract:
... Herein, we applied PmST1 (a sialyltransferase) to achieve acceptor-mediated regioselective sialylation (AMRS) on the nonreducing end GalNH₂ or GalAz (2-azido-2-deoxy galactose). Thus, C5 and C8-modified sialic acid was efficiently assembled on GalNH₂ (or GalAz) to achieve the synthesis of the GAA-7 (one of the echinodermatous gangliosides with higher neuritogenic activity) glycan moiety. ...
DOI:
10.1039/d1cc00653c

16. An efficient one-pot synthesis of indanone fused heterocyclic compounds via SeO2/FeCl3 promoted intramolecular Friedel-Craft acylation reaction

Author:
Zhang, Huan; Wang, Qi; Huang, Lu; Tian, Ziye; Zhang, Shunguang; Zhang, Youlai
Source:
Tetrahedron letters 2021 pp. 153070
ISSN:
0040-4039
Subject:
moieties,   etc   ; acylation; indans; isoflavones; oxidation; synthesis;     Show all 6 Subjects
Abstract:
... Indanones have been shown to exhibit a broad range of biological activities. An efficient and straightforward synthetic method for generating indanone fused heterocyclic compounds which contains a unique tetracyclic isoflavone moiety was developed. This unprecedented one-pot route utilizes a wide spread of substrates through three-step tandem Riley oxidation/Friedel-Crafts reaction/oxidation with ...
DOI:
10.1016/j.tetlet.2021.153070

17. Reactivity of P₄ butterfly complexes towards NHCs – generation of a metal-bridged P₂ dumbbell complex

Author:
Reichl, Stephan; Grünbauer, Rebecca; Balázs, Gábor; Scheer, Manfred
Source:
Chemical communications 2021 v.57 no.27 pp. 3383-3386
ISSN:
1364-548X
Subject:
moieties,   etc   ; butterflies; carbenes; heterocyclic nitrogen compounds;     Show all 4 Subjects
Abstract:
... The reactivity of the P₄ butterfly complexes [{Cp′′′Fe(CO)₂}₂(μ,η¹:¹-P₄)] (A, Cp′′′ = C₅H₂ᵗBu₃) and [{Cp*Cr(CO)₃}₂(μ,η¹:¹-P₄)] (B, Cp* = C₅(CH₃)₅) towards the N-heterocyclic carbene IMe (1,3,4,5-tetramethyl-imidazol-2-ylidene) is reported. The reaction of A affords [P(IMe)₂][Fe(CO)₂Cp′′′] (1) or [P(IMe)₂][{Cp′′′Fe}₂(μ,η³:³-P₃)] (2), the latter possessing a P₃-allylic moiety. In contrast, the react ...
DOI:
10.1039/d1cc00615k

18. Characterization of a 3-hydroxyanthranilic acid 6-hydroxylase involved in paulomycin biosynthesis

Author:
Ding, Yong; Wang, Min; Li, Jine; Li, Pengwei; Guo, Zhenyan; Chen, Yihua
Source:
Biochemical and biophysical research communications 2021 v.543 pp. 8-14
ISSN:
0006-291X
Subject:
moieties,   etc   ; biosynthesis; chorismic acid; glycosylation; oxidoreductases; research;     Show all 6 Subjects
Abstract:
... Paulomycins (PAUs) refer to a group of glycosylated antibiotics with attractive antibacterial activities against Gram-positive bacteria. They contain a special ring A moiety that is prone to dehydrate between C-4 and C-5 to a quinone-type form at acidic condition, which will reduce the antibacterial activities of PAUs significantly. Elucidation of the biosynthetic mechanism of the ring A moiety ma ...
DOI:
10.1016/j.bbrc.2021.01.042

19. Pseudo in situ construction of high-performance thermoelectric composites with a dioxothiopyrone-based D–A polymer coating on SWCNTs

Author:
Qu, Wen-Qiang; Gao, Cai-Yan; Zhang, Ping-Xia; Fan, Xin-Heng; Yang, Lian-Ming
Source:
RSC advances 2021 v.11 no.15 pp. 8664-8673
ISSN:
2046-2069
Subject:
moieties,   etc   ; carbon nanotubes; coagulation; electrical conductivity; polymers;     Show all 5 Subjects
Abstract:
... Organic polymer/inorganic particle composites with thermoelectric (TE) properties have witnessed rapid progress in recent years. Nevertheless, both development of novel polymers and optimization of compositing methods remain highly desirable. In this study, we first demonstrated a simulated in situ coagulation strategy for construction of high-performance thermoelectric materials by utilizing sing ...
DOI:
10.1039/d0ra10625a

20. Facile Construction of an Amino-1,3-Oxazine Scaffold using Burgess Reagent Under Mild Conditions

Author:
Fuchino, Kouki; Masui, Moriyasu; Yoshida, Shuhei; Kusakabe, Ken-ichi
Source:
Tetrahedron letters 2021 v.64 pp. 152684
ISSN:
0040-4039
Subject:
moieties,   etc   ; cyclization reactions; phosphorus pentoxide; synthesis;     Show all 4 Subjects
Abstract:
... The development of a cyclization reaction to access amino-1,3-oxazines under mild conditions is described. The synthesis was achieved using dehydrating reagents, such as phosphorus pentoxide and Burgess reagent. In particular, the cyclization with Burgess reagent proceeded under mild conditions and tolerated potentially labile functional groups, such as the acetoxy group, and therefore can be used ...
DOI:
10.1016/j.tetlet.2020.152684