19377-04-9Relevant articles and documents
Lewis Acid Regulated Divergent Catalytic Reaction between Quinone Imine Ketals (QIKs) and 1,3-Dicarbonyl Compounds: Switchable Access to Multiple Products Including 2-Aryl-1,3-Dicarbonyl Compounds, Indoles, and Benzofurans
Chen, Xingyu,Lu, Sixian,Deng, Ping,Chang, Xiaoqiang,Zhao, Yifan,Ma, Yue,Zhang, Dong,Xia, Fei,Yang, Lan,Wang, Jigang,Sun, Peng
supporting information, p. 94 - 102 (2021/10/05)
A catalytic Lewis acid regulated reaction between quinone imine ketals (QIKs) and 1,3-dicarbonyl compounds provides a divergent and tunable approach to a variety of skeletons, including a series of 2-aryl-1,3-dicarbonyl compounds, indoles, and benzofurans. The use of lithium chloride and ferrous bromide gives C3- or C2-alkylation products of the QIKs. The combination of ferrous bromide and trifluoromethanesulfonic acid delivers indole derivatives. Sequential hydrolysis and C3-alkylation occur in the presence of ytterbium (III) trifluoromethanesulfonate and stoichiometric amounts of water. When the reaction is performed with trifluoromethanesulfonic acid and stoichiometric amounts of water, benzofuran is obtained. This protocol utilizes mild conditions, exhibits regio- and chemoselectivity, and has broad functional group tolerance. (Figure presented.).
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.
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.