6279-07-8Relevant academic research and scientific papers
Direct C(sp3)–H Sulfonylation of Xanthene Derivatives with Sodium Sulfinates by Oxidative Copper Catalysis
Jiang, Huanfeng,Song, Qinghao,Sun, Yanping,Zhang, Min,Zhao, He
supporting information, p. 371 - 377 (2021/12/24)
By employing a readily available CuCl/DDQ catalyst system, we herein report a direct C(sp3)–H sulfonylation of xanthene derivates with odorless sodium sulfinates. Various 9H-xanthenes, thioxanthenes, and 9,10-dihydroacridines are efficiently transformed into the desired benzylic sulfonyl products via a radical/radical cross-coupling process, proceeding with the merits of broad substrate scope, operational simplicity, good functional group compatibility, and mild reaction conditions.
Electrochemically Mediated Direct C(sp3)?H Sulfonylation of Xanthene Derivatives
Wei, Wan-Jie,Zhong, Yu-Jing,Feng, Yu-Feng,Gao, Lei,Tang, Hai-Tao,Pan, Ying-Ming,Ma, Xian-Li,Mo, Zu-Yu
supporting information, p. 726 - 731 (2022/01/06)
The construction of C(sp3)-sulfonyl bonds through direct sulfonylation of C(sp3)?H bond presents a number of challenges, so an electrochemical oxidation-induced direct sulfonylation of the xanthene C(sp3)?H bond was developed. Significant advantages of this method are high atom efficiency, functional group tolerance, transition metal- and oxidant-free conditions. The in vitro cytotoxicity of all product is evaluated by MTT assay against human cancer cell lines. The results reveal that most of the compounds 3 da and 3 af have good inhibitory activity on tumor cell lines. (Figure presented.).
A radical-radical cross-coupling reaction of xanthene with sulfonyl hydrazides: Facile access to xanthen-9-sulfone derivatives
Bhowmik, Arup,Das, Sumit,Deb, Indubhusan,Karmakar, Sudip,Mishra, Aniket,Mondal, Imtiaj,Roy, Shantonu,Saha, Shubhra Jyoti,Sarkar, Writhabrata
supporting information, p. 2902 - 2905 (2022/03/09)
A straightforward strategy for direct incorporation of sulfonyl units into a xanthene moiety for accessing xanthen-9-sulfone derivatives in good to excellent yields has been established via metal-free radical-radical cross-coupling reaction of xanthenes and sulfonyl hydrazides. Using easily accessible starting materials, this methodology proceeds efficiently with a high degree of functional group compatibility and with a wide scope of both xanthenes and sulfonyl hydrazides under operationally simple reaction conditions. Mechanistic investigations revealed that sulfonyl radicals could be generated from sulfonyl hydrazides in the presence of TBHP under an oxygen atmosphere.
Lewis acid-catalysed one pot synthesis of substituted xanthenes
Boe, Esther,Hillringhaus, Tim,Nitsch, Jacqueline,Klussmann, Martin
supporting information; experimental part, p. 1744 - 1748 (2011/04/24)
A direct synthesis of substituted xanthenes from salicylaldehydes and cyclohexenones or tetralones has been developed. The reaction is catalysed by Lewis acids like scandium triflate and furnishes substituted xanthenes in good to excellent yields using either microwave or thermal heating. Microwave heating results in significantly shortened reaction times of 30 min and generally higher yields.
Iron-catalyzed, microwave-promoted, one-pot synthesis of 9-substituted xanthenes by a cascade benzylation-cyclization process
Xu, Xiaobing,Xu, Xiaolei,Li, Hongfeng,Xie, Xin,Li, Yanzhong
supporting information; experimental part, p. 100 - 103 (2010/03/04)
"Chemical Equation Presented" An efficient iron-catalyzed, microwave-promoted cascade benzylation-cyclization of phenols is reported. Benzyl acetates, benzyl bromides, and benzyl carbonates are suitable benzylating reagents. The reactions proceed to afford both 9-aryl and 9-alkyl xanthene derivatives in good to high yields using FeCI3 as the catalyst under MW irradiation conditions
Gas-phase Reactions of 2-Benzyl- and 2-Benzoyl-phenoxyl Radicals, and of 2-Phenoxybenzyl Radicals: Examples of New Hydrogen-transfer Processes
Cadogan, J. I. G.,Hutchison, H. Susan,McNab, Hamish
, p. 385 - 393 (2007/10/02)
Generation of the 2-benzylphenoxyl radical 23 or the 2-phenoxybenzyl radical 24 by flash vacuum pyrolysis of the ethers 8 or 9, or the oxalate 19, respectively, leads to fluoren-1-ol 22 together with 2-benzylphenol 7 and a low yield of xanthene 21.Pyrolysis of the para-substituted derivatives 11 and 20 gives an analogous distribution of products, including two isomeric methylxanthenes 28 and 29 formed via the spirodienyl 27.The reactions of the corresponding 2-benzoylphenoxyl radicals give information on the mechanism of these processes.Thus the formation of the fluorenones 37 and 43 provides evidence for the hydrogen-abstraction mechanism (Scheme 4) of fluorene formation.Secondly, a detailed study of the ratios of xanthones 41 and 42 under a variety of pyrolysis conditions suggests that such 6-membered-ring products are formed by sigmatropic shifts in the spirodienyl, rather than direct cyclisation of the phenoxyl or benzoyl radicals.
New Gas Phase Reactions of Substituted Benzyl, Phenylaminyl, and Phenoxyl Radicals. Rearrangements to Fused 5- and 6-Membered Heterocyclic Systems
Cadogan, J. I. G.,Hickson, Clare L.,Hutchison, H. Susan,McNab, Hamish
, p. 643 - 644 (2007/10/02)
Flash vacuum pyrolysis studies of substituted benzyl, phenylaminyl, and phenoxyl radicals have revealed three new classes of reactions: formation of five-membered ring products via intramolecular abstracion of an aromatic hydrogen atom, formation of six-membered rings via spirodienyl radical intermediates, and isomerisation of o-phenoxybenzyl into o-benzylphenoxyl radicals and vice versa.
