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.
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