61820-94-8Relevant academic research and scientific papers
Acridine Orange Hemi(Zinc Chloride) Salt as a Lewis Acid-Photoredox Hybrid Catalyst for the Generation of α-Carbonyl Radicals
Das, Sanju,Mandal, Tanumoy,De Sarkar, Suman
, p. 755 - 765 (2021/12/10)
A readily accessible organic-inorganic hybrid catalyst is reported for the reductive fragmentation of α-halocarbonyl compounds. The robust hybrid catalyst is a self-stabilizing combination of ZnCl2 Lewis acid and acridine orange as the photoactive organic dye. Mechanistic specifics of this hybrid catalyst have been studied in detail using both photophysical and electrochemical experiments. A systematic study enabled the discovery of the appropriate Lewis acid for the effective LUMO stabilization of α-halocarbonyl compounds and thereby lowering of reduction potential within the range of a standard organic dye. This strategy resolves the issues like dehalogenative hydrogenation or homo-coupling of alkyl radicals by guiding the photoredox cycle through an oxidative quenching pathway. The cooperativity between the photoactive organic dye and the Lewis acid counterparts empowers functionalization with a wide range of coupling partners through efficient and controlled generation of alkyl radicals and serves as an appropriate alternative to the expensive late transition metal-based photocatalysts. To demonstrate the application potential of this cooperative catalytic system, four different synthetic transformations of α-carbonyl bromides were explored with broad substrate scopes.
Building a Pyrazole–Benzothiadiazole–Pyrazole Photosensitizer into Metal–Organic Frameworks for Photocatalytic Aerobic Oxidation
Jin, Ji-Kang,Wu, Kun,Liu, Xin-Yi,Huang, Guo-Quan,Huang, Yong-Liang,Luo, Dong,Xie, Mo,Zhao, Yifang,Lu, Weigang,Zhou, Xiao-Ping,He, Jian,Li, Dan
supporting information, p. 21340 - 21349 (2021/12/17)
Charge separation plays a crucial role in regulating photochemical properties and therefore warrants consideration in designing photocatalysts. Metal–organic frameworks (MOFs) are emerging as promising candidates for heterogeneous photocatalysis due to their structural designability and tunability of photon absorption. Herein, we report the design of a pyrazole–benzothiadiazole–pyrazole organic molecule bearing a donor–acceptor–donor conjugated π-system for fast charge separation. Further attempts to integrate such a photosensitizer into MOFs afford a more effective heterogeneous photocatalyst (JNU-204). Under visible-light irradiation, three aerobic oxidation reactions involving different oxygenation pathways were achieved on JNU-204. Recycling experiments were conducted to demonstrate the stability and reusability of JNU-204 as a robust heterogeneous photocatalyst. Furthermore, we illustrate its applications in the facile synthesis of pyrrolo[2,1-a]isoquinoline-containing heterocycles, core skeletons of a family of marine natural products. JNU-204 is an exemplary MOF platform with good photon absorption, suitable band gap, fast charge separation, and extraordinary chemical stability for proceeding with aerobic oxidation reactions under visible-light irradiation.
Cu(OTf)2-Catalyzed efficient sulfonylation of vinyl azides with sodium sulfinates
Ning, Zhitao,Xu, Zheng,Liu, Ruikai,Du, Zhengyin
supporting information, p. 3492 - 3500 (2021/10/14)
A simple oxidative cross-coupling reaction between vinyl azides and sodium sulfinates was developed. This reaction uses commercial arylsulfinates that are more efficient, cheaper, and more stable as sulfonylation reagents, for efficiently, cheaply, and environmentally friendly synthesis of β-keto sulfones. And the reaction has the advantages of simple operation, high efficiency, good yield, and also has a wide range of functional group tolerance.
Metal-free radical thiocyanatosulfonation of terminal alkynes in aqueous medium
Zhang, Mingmei,Zeng, Xianghua
supporting information, p. 3326 - 3330 (2021/05/07)
Here we report a novel and practical approach for preparing (E)-β-(thiocyanato)vinyl sulfones through the 1,2-thiocyanatosulfonation of terminal alkynes with NH4SCN and sulfonyl hydrazides. Advantages of this reaction include mild conditions, the absence of metal, readily available reagents, a broad substrate scope, good functional group compatibility, and excellent stereoselectivity. The radical species-induced pathway is also demonstrated by mechanistic studies.
Copper-Catalyzed Aerobic Oxidative Cleavage of Unstrained Carbon-Carbon Bonds of 1,1-Disubstituted Alkenes with Sulfonyl Hydrazides
Yi, Dong,He, Linying,Qi, Zhongyu,Zhang, Zhijie,Li, Mengshun,Lu, Ji,Wei, Jun,Du, Xi,Fu, Qiang,Wei, Siping
supporting information, p. 859 - 865 (2021/03/04)
Alkoxy radical-mediated carbon-carbon bond cleavages have emerged as a powerful strategy to complement traditional ionic-type transformations. However, carbon-carbon cleavage reaction triggered by alkoxy radical intermediate derived from the combination of alkyl radical and dioxygen, is scarce and underdeveloped. Herein, we report alkoxy radical, which was generated from alkyl radical and dioxygen, mediated selective cleavage of unstrained carbon-carbon bond for the oxysulfonylation of 1,1-disubstituted alkenes, providing facile access to a variety of valuable β-keto sulfones. Mechanistic experiments indicated alkoxy radical intermediate that underwent subsequent regioselective β-scission might be involved in the reaction and preliminary computational studies were conducted to provide a detailed explanation on the regioselectivity of the C—C bond cleavage. Notably, the strategy was successfully applied for constructing uneasily obtained architecturally intriguing molecules.
Copper-catalyzed aerobic oxidative cross-coupling reactions of vinylarenes with sulfinate salts: A direct approach to β-ketosulfones
Chen, Yu,Xu, Lei,Wang, Biyu,Jiang, Jingjing,Sun, Yixiang,Li, Longchun
, (2021/01/25)
A copper-catalyzed aerobic oxidative cross-coupling reactions for the synthesis of β-ketosulfones via formation of a C[sbnd]S bond has been demonstrated. Promoted by the crucial copper catalyst, perfect selectivity and good to excellent yields could be achieved. This method, including inexpensive copper catalyst, wide functional group tolerance, and open air conditions, make it very attractive and practical. More importantly, it also provides a versatile tool for the construction of β-ketosulfones from basic starting materials under mild conditions.
Method for synthesizing beta-ketosulfone derivative under mild condition and obtained beta-ketosulfone derivative
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Paragraph 0044; 0045, (2021/08/28)
The invention discloses a method for synthesizing a beta-ketosulfone derivative under a mild condition, which comprises the following steps: dissolving aryl olefin and sodium sulfinate in a solvent in a reaction container, adding an acidic additive, sealing the reaction container under the conditions that air exists in the reaction container and no transition metal exists, and purifying after reaction to obtain the beta-ketosulfone derivative. The free radical addition oxidation reaction of olefin and sulfinic acid can be realized under the mild condition without transition metal, the reaction raw materials are cheap and easy to obtain, no organic metal reagent or transition metal is needed, air is used as an oxidizing agent, no dangerous peroxide or persulfide is needed, and the method is compatible with air. The method has the advantages of simple operation and the like, and overcomes the defects of transition metal participation, large catalyst consumption, expensive reagents, high method cost, more reaction steps, more by-products and the like in the prior art.
Dioxygen-Triggered Oxosulfonylation/Sulfonylation of Terminal Olefins toward β-Keto Sulfones/Sulfones
Wang, Yanjie,Zhao, Yuhan,Cai, Changqun,Wang, Lingyun,Gong, Hang
supporting information, p. 8296 - 8301 (2021/11/13)
A dioxygen-triggered oxosulfonylation/sulfonylation of unactivated olefins to achieve β-keto sulfones/sulfones has been developed. Interestingly, pluralistic mechanisms were found when different types of compounds were applied as substrates, and different products were achieved. The reaction is carried out with a high atomic efficiency in the absence of a metal and a catalyst at room temperature under an air atmosphere. Importantly, as a proof-of-concept, a bioactive molecule was synthesized on a gram-scale level using this method.
Photosensitizer-free synthesis of β-keto sulfones: Via visible-light-induced oxysulfonylation of alkenes with sulfonic acids
Hong, Yun-Yun,Peng, Sha,Peng, Zhen,Tang, Shan-Shan,Xie, Long-Yong,Xu, Xiang-Qun,Yang, Li-Hua
supporting information, p. 4537 - 4541 (2021/05/31)
A practical and environment-friendly methodology for the construction of β-keto sulfones through visible-light induced direct oxysulfonylation of alkenes with sulfonic acids at ambient temperature under open-air conditions was developed. Most importantly, the reaction proceeded smoothly without the addition of any photocatalyst or strong oxidant, ultimately minimizing the production of chemical waste.
Sulfated tungstate/dioxygen: A new catalytic system for oxysulfonylation of styrenes to form β-keto sulfones
Akamanchi, Krishnacharya G.,Autade, Snehalata B.,Kulkarni, Raghavendra V.,Wagh, Ganesh D.
, p. 10554 - 10561 (2020/07/14)
A new system for synthesis of a wide range of β-keto sulfones using sulfated tungstate as a heterogeneous catalyst and oxygen as an environmentally benign oxidant with aryl hydrazides and styrenes as reacting counterparts has been developed. The preliminary experimental results support the involvement of free radical species. Thus, aryl sulfonyl free radicals, generated by oxidation of aryl sulfonyl hydrazides, subsequently undergo a tandem addition to styrenes to form intermediate benzyl free radicals, and oxygen capture and oxidation to furnish β-keto sulfones. The method is mild and efficient with easy workup procedures. The catalyst is recyclable. This journal is
