727-31-1Relevant academic research and scientific papers
Electrochemical Vicinal Difluorination of Alkenes: Scalable and Amenable to Electron-Rich Substrates
Doobary, Sayad,Sedikides, Alexi T.,Caldora, Henry P.,Poole, Darren L.,Lennox, Alastair J. J.
supporting information, p. 1155 - 1160 (2019/12/11)
Fluorinated alkyl groups are important motifs in bioactive compounds, positively influencing pharmacokinetics, potency and conformation. The oxidative difluorination of alkenes represents an important strategy for their preparation, yet current methods are limited in their alkene-types and tolerance of electron-rich, readily oxidized functionalities, as well as in their safety and scalability. Herein, we report a method for the difluorination of a number of unactivated alkene-types that is tolerant of electron-rich functionality, giving products that are otherwise unattainable. Key to success is the electrochemical generation of a hypervalent iodine mediator using an “ex-cell” approach, which avoids oxidative substrate decomposition. The more sustainable conditions give good to excellent yields in up to decagram scales.
Nitrosoarenes as Nitrogen Source for Generation of Sulfonamides with the Insertion of Sulfur Dioxide under Metal-Free Conditions?
Wang, Xuefeng,Lin, Yanmei,Liu, Jin-Biao,He, Fu-Sheng,Kuang, Yunyan,Wu, Jie
supporting information, p. 1098 - 1102 (2020/07/06)
A metal-free reaction of nitrosoarenes, aryldiazonium tetrafluoroborates, and sulfur dioxide under mild conditions is developed, giving rise to sulfonamides in moderate to good yields. This transformation proceeds efficiently at room temperature in the presence of cyclohexa-1,4-diene with a broad reaction scope. Good functional group compatibility is observed, including cyano, halo, and ester. A plausible mechanism involving a radical process with the insertion of sulfur dioxide is proposed, and cyclohexa-1,4-diene serves as the reductant during the transformation.
Triple Mode of Alkylation with Ethyl Bromodifluoroacetate: N, or O-Difluoromethylation, N-Ethylation and S-(ethoxycarbonyl)difluoromethylation
Polley, Arghya,Bairy, Gurupada,Das, Pritha,Jana, Ranjan
supporting information, p. 4161 - 4167 (2018/09/21)
In this report, we have explored a triple mode of chemical reactivity of ethyl bromodifluoroacetate. Typically, bromodifluoroacetic acid has been used as a difluorocarbene precursor for difluoromethylation of soft nucleophiles. Here we have disclosed nucleophilicity and base dependent divergent chemical reactivity of ethyl bromodifluoroacetate. It furnishes lithium hydroxide and cesium carbonate promoted difluoromethylation of tosyl-protected aniline and electron-deficient phenols respectively. Interestingly, switching the base from lithium hydroxide to 4-N,N-dimethylamino pyridine (DMAP) tosyl-protected anilines afforded the corresponding N-ethylation product. Whereas, highly nucleophilic thiophenols furnished the corresponding S-carboethoxydifluoromethylation product via a rapid SN2 attack to the bromine atom prior to the ester hydrolysis. This mechanistic divergence was established through several control experiments. It was revealed that difluoromethylation reaction proceeds through a tandem in situ ester hydrolysis/decarboxylative-debrominative difluorocarbene formation and subsequent trapping by the soft nucleophile-NHTs or electron-deficient phenolic ?OH groups. In the presence of DMAP the hydrolysis of the ester is perturbed instead a nucleophilic attack at the ethyl moiety provides the N-ethylation product. Hence, besides the development of a practical base-promoted N-difluoromethylation of amines and electron-deficient phenols, divergent reactivity pattern of inexpensive and user-friendly ethyl bromodifluoroacetate has been explored. (Figure presented.).
Differentiation of isomeric haloanilines by tosylation in combination with electrospray ionization mass spectrometry
Wang, Shanshan,Cheng, Yuanyuan,Chen, Mengmeng,Jiang, Kezhi
, p. 337 - 343 (2018/07/31)
Differentiation of the isomeric haloanilines still remains a challenging and?necessary?analytic task due to their identical retention time in chromatography and similar mass spectra. In this work, p-tosylation of haloanilines by reaction of haloanilines with p-toluenesulfonyl chloride resulted in the corresponding N-tosyl haloanilines. Fragmentation of protonated N-tosyl haloanilines in electrospray ionization tandem mass spectrometry (ESI-MS/MS) mainly resulted in tosyl cation, haloaniline radical cation, and halohydroxyaniline radical cation. The MS/MS of the three group isomeric derivatives showed significant difference in abundance distribution of these product ions, respectively. Theoretical calculations showed that the stability of the ion-neutral complex (INC) is a key factor influencing the relative intensity of the product ions. The three group isomeric derivatives were also separated by high performance liquid chromatograph (HPLC) at conventional conditions. p-Tosylation combined tandem MS (or HPLC) technique were carried out to realize the differentiation of isomeric haloanilines.
Transition-metal-free synthesis of aromatic amines via the reaction of benzynes with isocyanates
Seo, Jeong Hoon,Ko, Haye Min
supporting information, p. 671 - 674 (2018/01/19)
An unexpected reaction between benzynes and isocyanates to generate aromatic amines has been developed under transition-metal-free conditions. The in situ prepared anions formed through cleavage of the N–C bond in isocyanates, reacted with aryne precursor
Synthesis of: N -arylsulfonamides via Fe-promoted reaction of sulfonyl halides with nitroarenes in an aqueous medium
Jiang, Jun,Zeng, Sheng,Chen, De,Cheng, Chaozhihui,Deng, Wei,Xiang, Jiannan
supporting information, p. 5016 - 5020 (2018/07/25)
A fascinating Fe-promoted protocol for the synthesis of N-arylsulfonamides has been developed. Starting from commercially available nitroarenes and sulfonyl chlorides, moderate to excellent yields of the corresponding N-arylsulfonamides can be obtained. In particular, Fe dust serves as the sole reductant in the transformation and it can be easily performed on a large scale.
Copper-catalyzed cross-coupling of chloramine salts and arylboronic acids in water: A green and practical route to N-arylsulfonamides
Ouyang, Banlai,Zheng, Yanxia,Liu, Yi,Liu, Fei,Yao, Juying,Peng, Yiyuan
, p. 3694 - 3698 (2018/09/14)
A green and practical method for the synthesis of N-arylsulfonamides from chloramine salts and arylboronic acids is herein developed. The reaction proceeds readily in the presence of 5 mol% of CuI and 2.5 equiv. K2CO3 in water at room temperature, generating a variety of N-arylsulfonamides in moderate to good yields with good functional group tolerance.
Synthesis of N -Arylsulfonamides by a Copper-Catalyzed Reaction of Chloramine-T and Arylboronic Acids at Room Temperature
Ouyang, Banlai,Liu, Deming,Xia, Kejian,Zheng, Yanxia,Mei, Hongxin,Qiu, Guanyinsheng
supporting information, p. 111 - 115 (2017/12/27)
A copper-catalyzed Chan-Lam-coupling-like reaction of a (het)arylboronic acid and chloramine-T (or a related compound) has been developed for the synthesis of N -arylsulfonamides at room temperature in moderate to good yields, with good tolerance of functional groups. In this process, it is believed that chloramine-T serves as an electrophile.
NaI-Catalyzed Oxidative Amination of Aromatic Sodium Sulfinates: Synergetic Effect of Ethylene Dibromide and Air as Oxidants
Fu, Ying,Li, Quan-Zhou,Xu, Qin-Shan,Hügel, Helmut,Li, Ming-Peng,Du, Zhengyin
supporting information, p. 6966 - 6970 (2018/11/23)
A novel NaI-catalyzed oxidative amination of sodium sulfinates, employing both ethylene dibromide (EDB) and air as the oxidants, is described. EDB was first demonstrated to be a promising mild organic oxidant that in air, converted NaI into molecular iodine to promote the cross-coupling reactions of aromatic sodium sulfinates with amines to produce arylsulfonamides. Mechanistic studies indicated that a radical pathway might be involved in the reaction process.
ORGANIC REACTIONS CARRIED OUT IN AQUEOUS SOLUTION IN THE PRESENCE OF A HYDROXYALKYL(ALKYL)CELLULOSE OR AN ALKYLCELLULOSE
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Page/Page column 248; 249, (2017/08/21)
The present invention relates to a method of carrying out an organic reaction in aqueous solution in the presence of a hydroxyalkyl(alkyl)cellulose or an alkylcellulose.
