4875-10-9Relevant articles and documents
Iron(0)-Catalyzed Transfer Hydrogenative Condensation of Nitroarenes with Alcohols: A Straightforward Approach to Benzoxazoles, Benzothiazoles, and Benzimidazoles
Putta, Ramachandra Reddy,Chun, Simin,Choi, Seung Hyun,Lee, Seok Beom,Oh, Dong-Chan,Hong, Suckchang
, p. 15396 - 15405 (2020/12/02)
The iron-catalyzed hydrogen transfer strategy has been applied to the redox condensation of o-hydroxynitrobenzene with alcohol, leading to the formation of benzoxazole derivatives. A wide range of 2-substituted benzoxazoles were synthesized in good to excellent yields without the addition of an external redox agent. A series of control experiments provided a plausible mechanism. Furthermore, the reaction system was successfully extended to the synthesis of benzothiazoles and benzimidazoles.
Rational design of fluorescent probes for targeted: In vivo nitroreductase visualization
Chen, Ji-An,Gao, Jie,Gu, Xianfeng,Li, Mimi,Tan, Jiahui,Yin, Xiaofan,Zhao, Zhen
supporting information, p. 4744 - 4747 (2020/07/13)
Nitroreductase (NTR) has been recognized as a biomarker for identifying the hypoxic status of cancers. Therefore, it is of high scientific interest to design effective fluorescent probes for tracking NTR activity. However, studies on elucidation of the structure-performance relationship of fluorescent probes and those providing valuable insight into optimized probe design have rarely been reported. Three BODIPY based fluorescent probes were made by conjugation of para-, ortho-, and meta-nitrobenzene to the BODIPY core via a thiolether bond, respectively. Our study revealed that the linkage and nitro substituent position significantly influence the capability of nitroreductase detection.
Mitsunobu C-alkylation of β-alkoxycarbonyl 2-nitrobenzenesulfones and its use for the rapid synthesis of novel benzothiazine derivatives
Drábiková, Martina,Kraj?ovi?ová, Soňa,Soural, Miroslav
, p. 6296 - 6306 (2017/10/06)
Herein, we report the first examples of the Mitsunobu alkylation of β-alkoxycarbonyl 2-nitrobenzenesulfones. Wang resin was acylated with α-halocarboxylic acids followed by the reaction with 2-nitrothiophenols. After oxidation with m-chloroperbenzoic acid, the immobilized β-alkoxycarbonyl 2-nitrobenzensulfones were subjected to alkylation with various alcohols. The reaction outcome strongly depended on the selection of the alkylating species. After the reduction of the nitro group, acid-mediated cleavage and subsequent cyclization, the C2-(di)substituted benzothiazin-3(4H)-one 1,1-dioxides were obtained in high crude purities and good overall yields.
Dynamic kinetic resolution of allylic sulfoxides by Rh-catalyzed hydrogenation: A combined theoretical and experimental mechanistic study
Dornan, Peter K.,Kou, Kevin G. M.,Houk,Dong, Vy M.
supporting information, p. 291 - 298 (2014/01/23)
A dynamic kinetic resolution (DKR) of allylic sulfoxides has been demonstrated by combining the Mislow [2,3]-sigmatropic rearrangement with catalytic asymmetric hydrogenation. The efficiency of our DKR was optimized by using low pressures of hydrogen gas to decrease the rate of hydrogenation relative to the rate of sigmatropic rearrangement. Kinetic studies reveal that the rhodium complex acts as a dual-role catalyst and accelerates the substrate racemization while catalyzing olefin hydrogenation. Scrambling experiments and theoretical modeling support a novel mode of sulfoxide racemization which occurs via a rhodium π-allyl intermediate in polar solvents. In nonpolar solvents, however, the substrate racemization is primarily uncatalyzed. Computational studies suggest that the sulfoxide binds to rhodium via O-coordination throughout the catalytic cycle for hydrogenation.
O-Nitrophenyl sulfoxides: Efficient precursors for the mild preparation of alkenes
Lu, Xiao,Long, Timothy E.
supporting information; experimental part, p. 249 - 252 (2010/04/06)
(Chemical Equation Presented) o-Nitrophenyl sulfoxides were found to be efficient synthetic precursors of various alkene types. The elimination occurs in toluene and NaOAc to generate substituted and terminal alkenes. Alkene products were easily obtained in high purity due to the simultaneous precipitation of the o-nitrophenyl sulfenic acid byproduct. The methods described have practical applications for the preparation of unsaturated compounds under mild, thermolytic conditions. 2009 American Chemical Society.
PREPARATION OF ALKENES BY MILD THERMOLYSIS OF SULFOXIDES
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Page/Page column 29-30, (2010/07/02)
Embodiments of this disclosure, among others, encompass methods for generating alkenes under mild thermolytic conditions that can provide almost total conversion of a precursor compound to an alkene without isomerization or the need to chromatographically purify the final product By selectively blocking the amino and carboxy groups of the depvatized amino acid, the methods of the disclosure provide for the synthesis of a peptide having the vinylglycine moiety at either the carboxy or the amino terminus of the peptide The mild conditions for the thermolytic removal of an o-NO2-phenyl substituted aryl group ensure that there is minimal if any damage to thermally sensitive conjugates such as a peptide bearing the vinylglycine The methods of the present disclosure have practical applications for the preparation of unsaturated compounds under mild, thermolytic conditions.
Preparation of vinylglycines by thermolysis of homocysteine sulfoxides
Patel, Sravan Kumar,Long, Timothy E.
supporting information; experimental part, p. 5067 - 5070 (2009/12/01)
The synthesis and efficacy of preparing Cbz-VG-OMe (1) by thermolysis of alkyl and aryl homocysteine sulfoxides were surveyed. This investigation determined that aryl sulfoxide analogs were more effective for the reaction and that the 2-nitrophenyl analog 10f possessed a unique ability to syn eliminate at temperatures as low as 100 °C. The thermolysis of sulfoxide 10f was additionally discovered to occur under toluene reflux and when sodium acetate was added, Cbz-VG-OMe (1) could be obtained in high purity by simple filtration of the precipitated sulfenic acid byproduct 12. This mild protocol which was also applied in the synthesis of VG dipeptide 13 would have utility in the general synthesis of olefins and alkenes from 2-nitrophenylsulfoxides.
Unsymmetric aryl-alkyl disulfide growth inhibitors of methicillin-resistant Staphylococcus aureus and Bacillus anthracis
Turos, Edward,Revell, Kevin D.,Ramaraju, Praveen,Gergeres, Danielle A.,Greenhalgh, Kerriann,Young, Ashley,Sathyanarayan, Nalini,Dickey, Sonja,Lim, Daniel,Alhamadsheh, Mamoun M.,Reynolds, Kevin
, p. 6501 - 6508 (2008/12/21)
This study describes the antibacterial properties of synthetically produced mixed aryl-alkyl disulfide compounds as a means to control the growth of Staphylococcus aureus and Bacillus anthracis. Some of these compounds exerted strong in vitro bioactivity. Our results indicate that among the 12 different aryl substituents examined, nitrophenyl derivatives provide the strongest antibiotic activities. This may be the result of electronic activation of the arylthio moiety as a leaving group for nucleophilic attack on the disulfide bond. Small alkyl residues on the other sulfur provide the best activity as well, which for different bacteria appears to be somewhat dependent on the nature of the alkyl moiety. The mechanism of action of these lipophilic disulfides is likely similar to that of previously reported N-thiolated β-lactams, which have been shown to produce alkyl-CoA disulfides through a thiol-disulfide exchange within the cytoplasm, ultimately inhibiting type II fatty acid synthesis. However, the mixed alkyl-CoA disulfides themselves show no antibacterial activity, presumably due to the inability of the highly polar compounds to cross the bacterial cell membrane. These structurally simple disulfides have been found to inhibit β-ketoacyl-acyl carrier protein synthase III, or FabH, a key enzyme in type II fatty acid biosynthesis, and thus may serve as new leads to the development of effective antibacterials for MRSA and anthrax infections.
A comparison of commercial microwave reactors for scale-up within process chemistry
Moseley, Jonathan D.,Lenden, Philip,Lockwood, Mark,Ruda, Katinka,Sherlock, Jon-Paul,Thomson, Anthony D.,Gilday, John P.
, p. 30 - 40 (2012/12/31)
Seven commercially available microwave reactors designed for limited scale-up have been investigated using a highly reliable and robust reaction (the Newman-Kwart rearrangement). The use of a single reaction has enabled the comparison to be made across the range of different reactor types and scales. Overall, all reactors gave reliable scale-up from small scale, and performance equivalent to one another on large scale. A more detailed comparison between them is given in the concluding section.
N-alkylthio beta-lactams, alkyl-coenzyme a asymmetric disulfides, and aryl-alkyl disulfides as anti-bacterial agents
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Page/Page column 9, (2008/12/07)
The present invention provides N-alkylthio β-lactams and disulfide compounds (e.g., alkyl-coenzyme A asymmetric disulfides or aryl-alkyl disulfides), compositions containing such compounds, and method of their use as anti-bacterial agents.
