U.S. flag

An official website of the United States government

PubAg

Main content area

You searched for: Subject "hydrocarbons" Remove constraint Subject: "hydrocarbons"
Start Over

Search

21,096  Search Results

« Previous | 1 - 20 of 21,096 |
Number of results to display per page

Search Results

1. BF3·OEt2-catalyzed one-pot three-component access to diarylmethylazides

Author:
Prasad, Sure Siva; Joshi, Dirgha Raj; Kim, Ikyon
Source:
Tetrahedron letters 2021 v.67 pp. 152820
ISSN:
0040-4039
Subject:
aromatic hydrocarbons,   etc   ; aldehydes; materials;     Show all 3 Subjects
Abstract:
... A direct one-pot access to diarylmethylazides, versatile intermediates, from commercially available starting materials was enabled via three-component coupling of aldehydes, arenes, and TMSN₃ in the presence of a catalytic amount of BF₃·OEt₂. ...
DOI:
10.1016/j.tetlet.2020.152820

2. Pillar[6]arene: Light Cleaves Macrocycle to Linear Oligomer Biradical to Initiate Photopolymerization

Author:
Zhao, Shuai; Xue, Tanlong; Pei, Di; Song, Qiuyan; Pei, Zhichao; Nie, Jun; Chang, Yincheng
Source:
Organic letters 2021 v.23 no.5 pp. 1709-1713
ISSN:
1523-7052
Subject:
aromatic hydrocarbons,   etc   ; cytotoxicity; irradiation;     Show all 3 Subjects
Abstract:
... A novel kind of photoinitiator based on the macrocyclic molecule pillar[6]arene (P6OC2H5) is reported. Under light irradiation, P6OC2H5 was cleaved to a linear oligomer biradical, which could efficiently initiate free-radical photopolymerization. Owing to the absence of small molecular fragment generation, the macrocyclic photoinitiator exhibited a much lower migration rate and cytotoxicity than c ...
DOI:
10.1021/acs.orglett.1c00131

3. Synthesis of Enantiopure Hydrocarbon Cages Based on an Optically Resolved C₃-Symmetric Triaminotribenzotriquinacene

Author:
Zhang, Zhi-Qiang; Ren, Qing-Xia; Tian, Wan-Fa; Sun, Wen-Hua; Cao, Xiao-Ping; Shi, Zi-Fa; Chow, Hak-Fun; Kuck, Dietmar
Source:
Organic letters 2021 v.23 no.4 pp. 1478-1483
ISSN:
1523-7052
Subject:
hydrocarbons,   etc   ; Ursidae; enantiomers;     Show all 3 Subjects
Abstract:
... The synthesis of the enantiomerically pure, D₃-symmetric covalent hydrocarbon cages (+)-(M,M)-4 and (−)-(P,P)-4 bearing two C₃-symmetrically functionalized tribenzobenzotriquinacene (TBTQ) vertices is reported. The enantiomerically pure TBTQ building blocks (+)-(M)-5 and (−)-(P)-5 were prepared via the diastereomeric TBTQ triamides obtained by use of both Boc-d- and Boc-l-phenylglycine as chiral a ...
DOI:
10.1021/acs.orglett.1c00176

4. Interrupting the Barton–McCombie Reaction: Aqueous Deoxygenative Trifluoromethylation of O-Alkyl Thiocarbonates

Author:
Liu, Zhi-Yun; Cook, Silas P.
Source:
Organic letters 2021 v.23 no.3 pp. 808-813
ISSN:
1523-7052
Subject:
aromatic hydrocarbons,   etc   ; alkynes; phenol;     Show all 3 Subjects
Abstract:
... The site-selective trifluoromethylation of aliphatic systems remains an important challenge. This work describes a light-driven, copper-mediated trifluoromethylation of O-alkyl thiocarbonates. The reaction provides broad functional group tolerance (e.g., alkyne, alkene, phenol, free alcohol, electron-rich and -deficient arenes), thereby offering orthogonality and practicality for trifluoromethylat ...
DOI:
10.1021/acs.orglett.0c04039

5. Polymerization of a biscalix[5]arene derivative

Author:
Hirao, Takehiro; Fukuta, Kazushi; Haino, Takeharu
Source:
RSC advances 2021 v.11 no.29 pp. 17587-17594
ISSN:
2046-2069
Subject:
aromatic hydrocarbons,   etc   ; fullerene; polymerization; polymers;     Show all 4 Subjects
Abstract:
... Recent decades have seen an increased interest in the preparation of polymers possessing host or guest moieties as the end group, which has enabled new polymeric materials such as self-healable, shape-memory, and stimuli-responsive materials. Such polymers are commonly synthesized by tethering the host or guest moieties to polymers. On the other hand, there are limited reports demonstrating the pr ...
DOI:
10.1039/d1ra02276h

6. Sequential Ir/Cu-Mediated Method for the Meta-Selective C–H Radiofluorination of (Hetero)Arenes

Author:
Wright, Jay S.; Sharninghausen, Liam S.; Preshlock, Sean; Brooks, Allen F.; Sanford, Melanie S.; Scott, Peter J. H.
Source:
Journal of the American Chemical Society 2021 v.143 no.18 pp. 6915-6921
ISSN:
1520-5126
Subject:
aromatic hydrocarbons,   etc   ; fluorides; tetrabutylammonium compounds;     Show all 3 Subjects
Abstract:
... This article describes a sequential Ir/Cu-mediated process for the meta-selective C–H radiofluorination of (hetero)arene substrates. In the first step, Ir-catalyzed C(sp²)–H borylation affords (hetero)aryl pinacolboronate (BPin) esters. The intermediate organoboronates are then directly subjected to copper-mediated radiofluorination with [¹⁸F]tetrabutylammonium fluoride to afford fluorine-18 label ...
DOI:
10.1021/jacs.1c00523

7. Site-Selective Defluorinative sp³ C–H Alkylation of Secondary Amides

Author:
Yue, Wen-Jun; Day, Craig S.; Martin, Ruben
Source:
Journal of the American Chemical Society 2021 v.143 no.17 pp. 6395-6400
ISSN:
1520-5126
Subject:
hydrocarbons,   etc   ; Americans; alkylation; amides; journals;     Show all 5 Subjects
Abstract:
... A site-selective defluorinative sp³ C–H alkylation of secondary amides that rapidly and reliably incorporates gem-difluoroalkene motifs into previously unfunctionalized sp³ sites is disclosed. This protocol is distinguished by its mild conditions, wide scope, and exquisite site-selectivity, thus unlocking a new platform to introduce carbonyl isosteres at saturated hydrocarbon sites. ...
DOI:
10.1021/jacs.1c03126

8. 3,6-Fluoren[5]arenes: synthesis, structure and complexation with fullerenes C₆₀ and C₇₀

Author:
Wang, Jia-Qi; Han, Ying; Chen, Chuan-Feng
Source:
Chemical communications 2021 v.57 no.33 pp. 3987-3990
ISSN:
1364-548X
Subject:
aromatic hydrocarbons,   etc   ; chemical communication; fullerene;     Show all 3 Subjects
Abstract:
... A new class of macrocyclic arenes, 3,6-fluoren[5]arenes, were conveniently synthesized in good yields by one-step reaction. The 3,6-fluoren[5]arenes had symmetric pentagon structures with big and rich-electron cavities, which made them form 1 : 1 complexes with fullerenes C₆₀ and C₇₀. The association constants of the complexes were all greater than 10⁵ M⁻¹. ...
DOI:
10.1039/d1cc00916h

9. Ni-Catalyzed C–H Cyanation of (Hetero)arenes with 2-Cyanoisothiazolidine 1,1-Dioxide as a Cyanation Reagent

Author:
Ma, Junjie; Liu, Hao; He, Xin; Chen, Zhicheng; Liu, Yue; Hou, Chuanfu; Sun, Zhizhong; Chu, Wenyi
Source:
Organic letters 2021 v.23 no.8 pp. 2868-2872
ISSN:
1523-7052
Subject:
aromatic hydrocarbons,   etc   ; Lewis acids; alkaloids;     Show all 3 Subjects
Abstract:
... A nickel-catalyzed C–H cyanation reaction of arenes has been developed using 2-cyanoisothiazolidine 1,1-dioxide as an electrophilic cyanation reagent. Many different directing groups can be used in this cyanation to obtain a series of cyanation products with good yields. Adopting this strategy to introduce a cyano group, natural alkaloid menisporphine was successfully synthesized through cyano gro ...
DOI:
10.1021/acs.orglett.1c00468

10. Phosphonium Ylide-Mediated Programmable Fluorination to Access Mono- and Difluoromethylarenes

Author:
Zheng, Yu; Xie, Zhen-Zhen; He, Xian-Chen; Chen, Yan-Shan; Cheng, Wen-Shuo; Chen, Kai; Xiang, Hao-Yue; Chen, Xiao-Qing; Yang, Hua
Source:
Organic letters 2021 v.23 no.7 pp. 2538-2542
ISSN:
1523-7052
Subject:
aromatic hydrocarbons,   etc   ; agrochemicals; deprotonation; drugs;     Show all 4 Subjects
Abstract:
... Compounds bearing fluorinated moieties are pervasive in a wide range of pharmaceuticals and agrochemicals. The installation of fluorinated units is a persistently vital task in synthetic chemistry, where facile and manipulable assays are highly demanding. Herein, we establish a general and programmable fluorination strategy for the modular assembly of mono- and difluoromethylarenes through the con ...
DOI:
10.1021/acs.orglett.1c00457

11. Synthesis of N-Alkyl Anilines from Arenes via Iron-Promoted Aromatic C–H Amination

Author:
Falk, Eric; Gasser, Valentina C. M.; Morandi, Bill
Source:
Organic letters 2021 v.23 no.4 pp. 1422-1426
ISSN:
1523-7052
Subject:
aromatic hydrocarbons,   etc   ; Lewis acids; amination;     Show all 3 Subjects
Abstract:
... We report both an intermolecular C–H amination of arenes to access N-methylanilines and an intramolecular variant for the synthesis of tetrahydroquinolines. A newly developed, highly electrophilic aminating reagent was key for the direct synthesis of unprotected N-methylanilines from simple arenes. The reactions display a broad functional group tolerance and employ catalytic amounts of a benign ir ...
DOI:
10.1021/acs.orglett.1c00099

12. Self-assembly of curved aromatic molecules in nanoparticles

Author:
Bowal, Kimberly; Martin, Jacob W.; Kraft, Markus
Source:
Carbon 2021 v.182 pp. 70-88
ISSN:
0008-6223
Subject:
polycyclic aromatic hydrocarbons,   etc   ; carbon; energy; molecular dynamics;     Show all 4 Subjects
Abstract:
... The self-assembly and structure of nanoparticles containing curved polycyclic aromatic hydrocarbon molecules (cPAHs) are investigated using molecular modelling. These polar fullerene-like molecules are receiving increased attention recently due to the steric and electronic properties caused by the inclusion of five-membered ring(s) within their hexagonal lattice. In this work, the curPAHIP potenti ...
DOI:
10.1016/j.carbon.2021.05.013

13. C2-arylacylation of 2H-benzothiazoles with methyl arenes via Selectfluor oxidation

Author:
Lu, Qi; Sun, Xiao-Tong; Kong, Yao-Lei; Liu, Jin-Chuan; Chen, Bo; Weng, Jian-Quan
Source:
Tetrahedron letters 2021 v.75 pp. 153184
ISSN:
0040-4039
Subject:
aromatic hydrocarbons,   etc   ; catalysts; cross-coupling reactions; oxidation;     Show all 4 Subjects
Abstract:
... An efficient Selectfluor-oxidative protocol was developed for the direct C2-arylacylation of 2H-benzothiazoles via the radical reaction of 2H-benzothiazoles with methyl arenes. Selectfluor can effectively promote the oxidative cross-coupling without an external catalyst. This arylacylation reaction tolerates a wide range of functional groups affording 28 examples of the arylacylated products in 39 ...
DOI:
10.1016/j.tetlet.2021.153184

14. Sulfated polyborate-H2O assisted tunable activation of N-iodosuccinimide for expeditious mono and diiodination of arenes

Author:
Misal, Balu; Palav, Amey; Ganwir, Prerna; Chaturbhuj, Ganesh
Source:
Tetrahedron letters 2021 v.74 pp. 153154
ISSN:
0040-4039
Subject:
aromatic hydrocarbons,   etc   ; Bronsted acids; drugs; iodination; regioselectivity;     Show all 5 Subjects
Abstract:
... Owing to both Lewis and Bronsted acid active sites on sulfated polyborate under homogenous conditions, we were keen on developing iodination protocol of arenes that can meet the requirement of regioselectivity and higher yield. The sulfated polyborate activates N-iodosuccinimide for mono iodination of highly activated substrates viz. phenols, anilines under anhydrous condition. Water tunes sulfate ...
DOI:
10.1016/j.tetlet.2021.153154

15. Late-stage ligand functionalization via the Staudinger reaction using phosphine-appended 2,2′-bipyridine

Author:
Taher, Deeb; Wilson, Jessica R.; Ritch, Grayson; Zeller, Matthias; Szymczak, Nathaniel K.
Source:
Chemical communications 2021 v.57 no.46 pp. 5718-5721
ISSN:
1364-548X
Subject:
aromatic hydrocarbons,   etc   ; chemical communication; chemical reactions; ligands;     Show all 4 Subjects
Abstract:
... The ability of a phosphine-appended-2,2′-bipyridine ligand ((Ph₂P)₂bpy) to serve as a platform for late-stage ligand modifications was evaluated using tetrahedral (Ph₂P)₂bpyFeCl₂. We employed a post-metalation Staudinger reaction to install a series of functionalized arenes, including those containing Brønsted and Lewis acidic groups. This reaction sequence represents a versatile strategy to both ...
DOI:
10.1039/d1cc01407b

16. Chiral Nanochannels of Ordered Mesoporous Silica Constructed by a Pillar[5]arene-Based Host–Guest System

Author:
Cheng, Ming; Zhu, Fei; Xu, Weiwei; Zhang, Siyun; Dhinakaran, Manivannan Kalavathi; Li, Haibing
Source:
ACS applied materials & interfaces 2021 v.13 no.23 pp. 27305-27312
ISSN:
1944-8252
Subject:
aromatic hydrocarbons,   etc   ; enantioselectivity; porous media; silica;     Show all 4 Subjects
Abstract:
... The separation of racemic compounds by chiral nanochannels has attracted extensive attention. However, the fabrication of high-performance chiral nanochannels is still a challenge owing to the difficulty in magnifying the weak chiral interaction to macroscopic properties of materials. Herein, by introducing a l-alanine-pillar[5]arene host to achiral ordered mesoporous silica (OMS), chiral OMS nano ...
DOI:
10.1021/acsami.1c05790

17. Pillararene-based self-assemblies for electrochemical biosensors

Author:
Cao, Shuai; Zhou, Le; Liu, Chang; Zhang, Huacheng; Zhao, Yuxin; Zhao, Yanli
Source:
Biosensors & bioelectronics 2021 v.181 pp. 113164
ISSN:
0956-5663
Subject:
aromatic hydrocarbons,   etc   ; biosensors; electrochemistry; quinones; vigor;     Show all 5 Subjects
Abstract:
... The ingenious design and synthesis of novel macrocycles bring out renewed vigor of supramolecular chemistry in the past decade. As an intriguing class of macrocycles, pillararene and pillararene-based functional materials that are constructed through the noncovalent bond self-assembly approach have been undergoing a rapid growth, benefiting from their unique structures and physiochemical propertie ...
DOI:
10.1016/j.bios.2021.113164

18. Regioselective C–H Phosphorothiolation of (Hetero)arenes Enabled by the Synergy of Electrooxidation and Ultrasonic Irradiation

Author:
Meng, Ze-Yin; Feng, Cheng-Tao; Zhang, Ling; Yang, Qing; Chen, De-Xiang; Xu, Kun
Source:
Organic letters 2021 v.23 no.11 pp. 4214-4218
ISSN:
1523-7052
Subject:
aromatic hydrocarbons,   etc   ; electrochemistry; regioselectivity; thiocyanates; ultrasonic treatment;     Show all 5 Subjects
Abstract:
... An electrochemically regioselective C–H phosphorothiolation of (hetero)arenes with thiocyanate as the S source under ultrasonic irradiation has been developed. The synergistic cooperation of electrooxidation and ultrasonication markedly accelerated the C–H phosphorothiolation reaction. This mechanistically different method is distinguished by its wide substrate scope and transition-metal-free and ...
DOI:
10.1021/acs.orglett.1c01161

19. Redox-neutral functionalization of α-Csp³–H bonds of secondary cyclic amines: a highly atom-economical strategy for N-arylation/formal cross-dehydrogenative couplings

Author:
Jha, Priyankar; Husen, Saddam; Kumar, Ravindra
Source:
Green chemistry 2021 v.23 no.8 pp. 2950-2955
ISSN:
1463-9270
Subject:
aromatic hydrocarbons,   etc   ; dehydrogenation; green chemistry; mass spectrometry;     Show all 4 Subjects
Abstract:
... An efficient redox-neutral method has been developed for α-Csp³–H functionalization of secondary cyclic amines via concurrent N-arylation/formal cross dehydrogenation coupling (CDC) with sp²-C–H and sp³-C–H bonds of arenes and ketones, respectively. The developed protocol is operationally simple, highly atom economical and environmentally benign (E-factor = ca. 0.5). The reaction mechanism has bee ...
DOI:
10.1039/d0gc04258g

20. Synthesis of difluoromethylated diarylmethanes via Fe(OTf)₃-catalyzed Friedel–Crafts reaction of 2,2-difluoro-1-arylethyl phosphates

Author:
Yamamoto, Yoshihiko; Takase, Tomoya; Kuroyanagi, Eisuke; Yasui, Takeshi
Source:
Chemical communications 2021 v.57 no.32 pp. 3877-3880
ISSN:
1364-548X
Subject:
aromatic hydrocarbons,   etc   ; Lewis acids; chemical reactions; phosphates;     Show all 4 Subjects
Abstract:
... The Fe(OTf)₃-catalyzed Friedel–Crafts reaction of 2,2-difluoro-1-arylethyl phosphates with electron-rich (hetero)arenes afforded difluoromethylated diarylmethanes. Control experiments showed that Fe(OTf)₃ behaves as the Lewis acid, and that the phosphate leaving group and o- or p-alkoxy substituents on the substrates are necessary for the Fe(OTf)₃-catalyzed reaction to proceed under mild condition ...
DOI:
10.1039/d1cc00765c