82777-11-5Relevant articles and documents
Electrophotochemical Ring-Opening Bromination oftert-Cycloalkanols
Yamamoto, Kosuke,Toguchi, Hiroyuki,Kuriyama, Masami,Watanabe, Shin,Iwasaki, Fumiaki,Onomura, Osamu
, p. 16177 - 16186 (2021/09/13)
An electrophotochemical ring-opening bromination of unstrainedtert-cycloalkanols has been developed. This electrophotochemical method enables the oxidative transformation of cycloalkanols with 5- to 7-membered rings into synthetically useful ω-bromoketones without the use of chemical oxidants or transition-metal catalysts. Alkoxy radical species would be key intermediates in the present transformation, which generate through homolysis of the O-Br bond in hypobromite intermediates under visible light irradiation.
Copper-catalyzed radical ring-opening halogenation with HX
Bai, Ming,Duan, Xin-Hua,Guo, Li-Na,Liu, Shuai,Sun, Qing-Xin,Xu, Peng-Fei
, p. 8652 - 8655 (2021/09/04)
An efficient copper-catalyzed radical ring-opening halogenation with HX (aq) is described. This protocol features redox-neutral conditions, green halogen sources, and a broad substrate scope, providing practical access to distally chlorinated, brominated and iodinated alkyl ketones and alkyl nitriles with moderate to good yields. This journal is
Far-end halogenated alkyl ketone taking HX as halogen source and synthesis method of far-end halogenated alkyl ketone
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Paragraph 0032, (2021/08/21)
The invention relates to a far-end halogenated alkyl ketone taking HX as a halogen source and a synthesis method of the far-end halogenated alkyl ketone. The method comprises the following steps that: cycloalkyl peroxy alcohol and a copper acetate catalyst are added in a nitrogen atmosphere, then HCl, HBr and an HI solution are added as halogens, and stirring is carried out at normal temperature; after a reaction is finished, sufficient water is added to extract a reaction solvent N-methyl pyrrolidone, performing washing with saturated saline solution, an organic phase is dried with anhydrous sodium sulfate, the organic phase is concentrated under reduced pressure, so that the solvent can be removed; and column chromatography is performed on the organic phase to obtain a target product. According to the far-end halogenated alkyl ketone taking the HX as the halogen source and the synthesis method of the far-end halogenated alkyl ketoneinvention, industrial bulk raw materials HCl, HBr and an HI solution are used as the halogen source, free radical halogenation of C-C bond cracking is realized, and the far-end halogenated alkyl alkyl ketone compound is obtained with high yield; the byproduct of the reaction is water, so that the environmental pollution is reduced, and the industrial production benefit is greatly improved.
Intramolecular Cyclization of Brominated Oxime Ether Promoted with Ytterbium(0) to the Synthesis of Cyclic Imines
Wang, Yiqiong,Huang, Fei,Zhang, Songlin
supporting information, p. 5178 - 5181 (2020/08/13)
The first utility of ytterbium(0) as a mediating-metal in the intramolecular cyclization of brominated oxime ether was reported in this paper. In contrast to the prior methods, the N–O bond was used as a receptor of nucleophilic reagent, rather than as a source of N-centered radicals. Cyclic imines were obtained in this one-pot reaction with a broad scope of substrates and feasible reaction conditions.
Ring-opening iodination and bromination of unstrained cycloalkanols through ?-scission of alkoxy radicals
Shi, Jiang-Ling,Wang, Yuankai,Wang, Zixuan,Dou, Bowen,Wang, Jianbo
supporting information, p. 5002 - 5005 (2020/05/18)
Ring-opening iodination or bromination of unstrained cycloalkanols with NaI or NaBr and PhI(OAc)2 under visible light irradiation is developed. In this protocol the concentration of I2is modulated through the generation of triiodide (I3-), thus significantly avoiding undesired side reactions. The reaction is under mild conditions and has a wide substrate scope, thus providing a practically useful method for accessing ω-iodo or ω-bromoketones.
Iminyl Radicals by Reductive Cleavage of N-O Bond in Oxime Ether Promoted by SmI2: A Straightforward Synthesis of Five-Membered Cyclic Imines
Huang, Fei,Zhang, Songlin
supporting information, p. 7430 - 7434 (2019/10/11)
A new generation method of N-centered radicals from the reductive cleavage of the N-O bond in oxime ether promoted by SmI2 is reported for the first time. The in-situ-generated N-centered radicals underwent intramolecular cyclization to afford five-membered cyclic imines in two manners: N-centered radical addition and N-centered anion nucleophilic substitution. From a synthetic point of view, an efficient synthetic method of five-membered cyclic imines was developed. A mechanism of the transformation was proposed.
Chemoenzymatic Synthesis of Substituted Azepanes by Sequential Biocatalytic Reduction and Organolithium-Mediated Rearrangement
Zawodny, Wojciech,Montgomery, Sarah L.,Marshall, James R.,Finnigan, James D.,Turner, Nicholas J.,Clayden, Jonathan
, p. 17872 - 17877 (2019/01/04)
Enantioenriched 2-aryl azepanes and 2-arylbenzazepines were generated biocatalytically by asymmetric reductive amination using imine reductases or by deracemization using monoamine oxidases. The amines were converted to the corresponding N′-aryl ureas, which rearranged on treatment with base with stereospecific transfer of the aryl substituent to the 2-position of the heterocycle via a configurationally stable benzyllithium intermediate. The products are previously inaccessible enantioenriched 2,2-disubstituted azepanes and benzazepines.
Visible light-promoted ring-opening functionalization of unstrained cycloalkanols via inert C-C bond scission
Wang, Dongping,Mao, Jincheng,Zhu, Chen
, p. 5805 - 5809 (2018/07/13)
Described herein is a novel, useful, visible light-promoted ring-opening functionalization of unstrained cycloalkanols. Upon scission of an inert cyclic C-C σ-bond, a set of medium- and large-sized rings are readily brominated under mild reaction conditio
Visible-light-enhanced ring opening of cycloalkanols enabled by br?nsted base-tethered acyloxy radical induced hydrogen atom transfer-electron transfer
Zhao, Rong,Yao, Yuan,Zhu, Dan,Chang, Denghu,Liu, Yang,Shi, Lei
supporting information, p. 1228 - 1231 (2018/02/23)
A metal-free ring opening/halogenation of cycloalkanols, which combines both PPO/TBAX oxidant system and blue LEDs irradiation, is presented. This method produces diverse γ, α, and even more remotely halogenated ketones in moderate to excellent yields under mild conditions. Interestingly, experimental and computational studies demonstrate the novel ring size-dependent concerted/stepwise (four-/five- to eight-membered rings) hydrogen atom transfer-electron transfer induced by Br?nsted base-tethered acyloxy radical, which indicates distinct advantages brought by the cyclic structure of diacyl peroxides.
Photoredox-Catalyzed Decarboxylative Alkylation of Silyl Enol Ethers to Synthesize Functionalized Aryl Alkyl Ketones
Kong, Weiguang,Yu, Changjiang,An, Hejun,Song, Qiuling
, p. 349 - 352 (2018/01/28)
Photoredox-catalyzed decarboxylative alkylation of silyl enol ethers has been developed. Diverse functionalized aryl alkyl ketones were afforded in modest to good yields using N-(acyloxy)phthalimide as an easy access alkyl radical source under mild and operationally simple conditions. The excellent performance of drug molecules such as fenbufen and indomethacin and naturally occurring carboxylic acids such as stearic acid and dehydrocholic acid further demonstrated the practicability of the reaction.
