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hypervalent iodine mediated C-H amination of quinoxalinones with heteroaromatic amines under metal-free conditions

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Chinese Chemical Letters 2021年第8期32卷 2559-2561页

作者： Qing-Qing Han De-Mao Chen Zu-Li Wang Yuan-Yuan Sun Shao-Hui Yang Jing-Cheng Song Dao-Qing Dong College of Chemistry and Pharmaceutical Sciences Qingdao Agricultural UniversityQingdao 266109China

An efficient and facile method for C-H amination of quinoxalinones with heteroaromatic amines under metal-free conditions has been *** the presence of hypervalent PIDA reagent,the desired products with various groups ... 详细信息

关键词： hypervalent iodine Amination Quinoxalinones Metal-free Heteroaromatic amines

Fluoroalcohol-mediated reductive iodonio-Claisen rearrangement： Synthesis of complex ortho-substituted-allyl iodoarenes

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Frontiers of Chemical Science and Engineering 2015年第3期9卷 359-368页

作者： Hem Raj Khatri Hai Nguyen James K. Dunaway Jianglong Zhu Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering The University of Toledo Toledo OH 43606 USA

Reductive iodonio-Claisen rearrangement （RICR） involving 23-iodanes and allyl or substituted-allyl silanes in fluoroalcohols, such as 1,1,1,3,3,3-hexafluoroi- sopropanol （HFIP） and 2,2,2-trifluoroethanol （TFE）, was studied for the synthesis of complex ortho-allyl or substituted-allyl iodoarenes. In comparison to the pre- viously reported condition involving boron trifluoride diethyl etherate, the RICR mediated by fluoroalcohols was found to proceed more effectively. The resulting complex ortho-allyl iodoarenes are useful synthetic intermediates and can be readily converted to various heterocyclic compounds.

关键词： hypervalent iodine allylation fluoroalcohol Claisen rearrangement heterocycles

Skeletal contraction:A novel strategy to access multisubstituted cyclobutane

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Green Synthesis and Catalysis 2022年第1期3卷 1-3页

作者： Chunfa Xu V.U.Bhaskara Rao Fen-Er Chen Institute of Pharmaceutical Science and Technology College of ChemistryFuzhou UniversityFuzhou 350108China Department of Chemical Biology Max Planck Institute for Molecular PhysiologyDortmund 44227Germany Engineering Center of Catalysis and Synthesis for Chiral Molecules Department of ChemistryFudan UniversityShanghai 200433China Shanghai Engineering Center of Industrial Asymmetric Catalysis for Chiral Drugs Fudan UniversityShanghai 200433China

The polysubstituted and spirocyclic cyclobutanes were efficiently constructed by the utilization of a novel skeletal contraction strategy which only took one-step synthesis from the readily accessible *** mechanistic studies indicated that a key intermediate N-aminated pyrrolidine was formed initially and subsequent extrusion of a nitrogen via a radical pathway completed the *** practical methodology was further highlighted by the concise,formal synthesis of the cytotoxic natural product piperarborenine B.

关键词： Cyclobutane Skeletal contraction hypervalent iodine Pyrrolidines Piperarboreine B

Solvent-controlled stereodivergent synthesis of E-and Z-enamines via metal-free formal C(sp2)-H amination ofα-substituted styrenes

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Green Synthesis and Catalysis

Green Synthesis and Catalysis 2024年第4期5卷 324-328页

作者： Dangui Wang Jinbei Yao Wentao Zhang Shuyue Zhang Huaibin Yu Laihu Peng Weijun Yao Zhifeng Dai Guojiao Wu Fangrui Zhong School of Pharmacy Weifang Medical UniversityWeifang 261053China Hubei Key Laboratory of Bioinorganic Chemistry&Materia Medica School of Chemistry and Chemical EngineeringHuazhong University of Science and Technology(HUST)Wuhan 430074China Zhejiang Sci-Tech University Hangzhou 310018China

C(sp2)-H amination represents an attractive approach for the synthesis of enamines,which is intrinsically associated with the challenge of controlling of stereochemistry and primarily relying on transition-metal ***,a metal-free C(sp2)-H amination ofα-substituted styrenes has been achieved,leading to stereodivergent formation of both E-and Z-enamines in 50%–97%yield under mild conditions by using PhI(OAc)2 as a green oxidant and ortho-phenylenediamines as nitrogen ***,the Z/E selectivity can be controlled readily by switching the reaction medium.E-isomers were formed preferentially in THF,whereas n-hexane favored the formation of *** mechanistic studies suggested that in situ formed ortho-benzoquinone diimides are the key intermediates,and there is a correlation between solvent polarity and *** study enriches the chemical repertoire of ortho-benzoquinone diimides particularly with respect to sustainable amination.

关键词： Enamines Stereodivergent synthesis Metal-free hypervalent iodine C(sp2)-H aminatio

NH_(4)SCN-Promoted Formal[3+3]Annulation for the Synthesis of 5-Arylated Pyrazolo[1,5-a]pyrimidines

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有机化学 2024年第9期44卷 2832-2840页

作者： Li Longlong He Xinyue Zhou Longsheng Qu Hengtong Feng Chengtao Xu Kun School of Pharmacy Anhui University of Chinese MedicineHefei 230012 College of Chemistry and Life Science Beijing University of TechnologyBeijing 100124

A formal[3+3]annulation of 3-aminopyrazoles with cinnamaldehydes or cinnamyl alcohols mediated by NH_(4)SCN has been *** protocol provides a practical route to construct 5-arylated pyrazolo[1,5-a]pyrimidines with high functional group *** use of NH_(4)SCN as the cyanide anion surrogate allows the transient generation of cyanohydrin,which shifts the reactive center within cinnamaldehydes from formyl group to alkene group to realize an opposite regiocontrol comparing with previous reports.

关键词： tandem cyclization hypervalent iodine regioselectivity pyrazolo[1,5-a]pyrimidine cinnamaldehyde

PIFA-Mediated Oxidation of β-Ketoamide: Synthesis of vicinal tricarbonyl Amides

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PIFA-Mediated Oxidation of β-Ketoamide: Synthesis of vicina...

河南省化学会2016年学术年会

作者： Yueyang Liu Yameng Wan Zhiguo Zhang Guisheng Zhang Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals Key Laboratory of Green Chemical Media and Reactions Ministry of Education School of Chemistry and Chemical Engineering Henan Normal University

A facile and direct synthetic method for the synthesis of vicinal tricarbonyl amides(VTAs) in moderate to excellent yields(62-93%) has been developed starting from readily availableβ-ketoamide in the presence of sole phenyliodine(III) bis(trifluoroacetate)(PIFA). The resulting products possess significant synthetic potential, making this approach a valuable addition to the traditional methods already available for the preparation of these molecules. Recent recearch indecated that the reversible addition of alcohols, amines and thiols can also occur to the central carbonyl group of the VTCs to afford the hemiketal, hemiaminal, and hemithioketal formation respectively. In this paper, we present our recent effort on the PIFA-mediated α-C-H bond oxidative reaction of β-ketoamide derivatives for the synthesis of VTAs.

关键词： Vicinal tricarbonyl amides(VTAs) vic-Diketoamides β-Dicarbonyl compounds β-Ketoamide PIFA hypervalent iodine

A Modular Synthesis of Heteroatom-Doped Buckybowls

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A Modular Synthesis of Heteroatom-Doped Buckybowls

中国化学会第十四届全国有机合成化学学术研讨会

作者： Dandan Zhou Qitao Tan Department of Chemistry Shanghai University

Buckybowls,bowl-shaped aromatic hydrocarbons resembling the fragments of fullerenes or the cap of single-walled carbon nanotubes,have attracted tremendous attention not only for their characteristic"open"geodesic geometry,but also for their unique physicochemical *** was firstly synthesized in 2003,which represents a basic subunit of *** heteroatoms have been doped into the framework of sumanene by replacing the benzylic carbon atoms with larger-sized S,Se,Te,Si,Ge,Sn and P atoms or by substituting the peripheral sp carbons with small-sized nitrogen *** herein report the synthesis of the first halogen-doped sumanene 2 from readily available1,5,9-triiodotriphenylene *** trithiasumanene 3,trisilasumanene 5 and the hitherto unknown parent triselenasumanene 4,three interesting heterobuckybowls of significant synthetic challenges,were efficiently prepared from 2 through non-pyrolytic *** containing group 14 elements(Si and Ge)have also been achieved using a three-fold rhodium-catalyzed cyclodehydrogenation of Si/Ge-H and C-H bonds as the key *** bowl-shaped geometry of 3 and the planar structure of 7c were further confirmed by single crystal X-ray diffraction.

关键词： functional organic materials buckybowl hypervalent iodine cyclodehydrogenation sumanene

Electrophilic α-cyanation toward α-cyano β-keto carbonyl compounds bearing a quaternary carbon center

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Electrophilic α-cyanation toward α-cyano β-keto carbonyl ...

中国化学会第九届全国有机化学学术会议

作者： Jiashen Qiu Yaofeng Wang Fuqing Pang Guirong Qi Fu-Xue Chen School of Chemical Engineering and the Environment Beijing Institute of Technology

Recently,the direct electrophilicα-cyanation ofβ-keto esters or amides（1）has been accomplished using active hypervalent iodine cyano reagent（C1）which was prepared in our laboratory.[1]With this procedure,the highly functionalized nitriles（2）bearing a quaternary carbon center were produced in high to excellent yields without any catalyst in DMF,which was finished less than 10 min at room *** addition,17 examples were experimented and the yield was up to 96%.During the direct electrophilicα-cyanation of racemates,we explored the catalytic asymmetric electrophilic cyanation of bulkyβ-keto ester *** order to solve the poor solubility of C1 in low polar solvent,cyanate C2 was used as a moderate cyano *** screening of different organocatalysts including cinchona alkaloids,chiral primary amines and phosphoric acids,it was found that 20 mol%of cinchonidine catalyzed the formation of product 2a in 60%yield and promising enantioselectivity at 59%*** studies to the better stereoselectivity are underway.

关键词： asymmetric catalysis cinchona alkaloids electrophilic cyanation hypervalent iodine

Metal-free Oxidative C-H Amination of 8-Acylaminoquinolines and Anilides with N-Fluorobenzenesulfonimide

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Metal-free Oxidative C-H Amination of 8-Acylaminoquinolines ...

中国化学会第十三届全国有机合成化学学术研讨会

作者： Yang Wang Ying Wang Zhenyu Guo Qian Zhang Dong Li School of Materials and Chemical Engineering Hubei University of Technology

Arylamines and their derivatives play an important role in biological active compounds,functional materials as well as organic synthetic intermediates.1-3 Thus the development of facile and efficient methods for constructing aromatic C-N bonds has attracted substantial *** recent years,N-fluorobenzenesulfonimide（NFSI） has received increasing attention and been disclosed as a nitrogen source for amination of aromatic,heteroaromatic,benzylic,and allylic C–H bonds.4 An oxidative C-H amination of 8-acylaminoquinolines and anilides with N-fluorobenzenesulfonimide（NFSI） have been developed,which was only mediated by a hypervalent iodine reagent Ph I（OPiv）2 without any metallic catalyst or *** protocol showed good air and moisture tolerance,functional groups compatibility,and gave the highly site-selective amination products in moderate to good yields,which would provide a novel and facile methodology for synthesis of arylamine compounds.

关键词： metal-free amination hypervalent iodine