Article
Chemistry, Organic
Ming-Zhong Zhang, Jing Tian, Min Yuan, Wan-Qi Peng, Yu-Zhu Wang, Peng Wang, Long Liu, Quan Gou, Huisheng Huang, Tieqiao Chen
Summary: A visible light-induced dioxygenation reaction of alpha,beta-unsaturated amides with N-hydroxy compounds was developed using non-toxic rose bengal dye as the photoredox catalyst, yielding beta-oxy alcohols with high chemoselectivity. Compared to traditional radical reactions, this photochemical protocol avoids the use of hazardous oxidants and transition metals, providing a safer and more eco-friendly synthesis approach.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Benxiang Zhang, Jiayan He, Yi Li, Tao Song, Yewen Fang, Chaozhong Li
Summary: Acylphosphonates with the 5,5-dimethyl-1,3,2-dioxophosphinanyl skeleton have been developed as efficient intermolecular radical acylation reagents for cobalt-catalyzed Markovnikov hydroacylation of unactivated alkenes at room temperature. The protocol shows broad substrate scope and good functional group compatibility, providing satisfactory yields of branched ketones. The proposed mechanism involves Co-H mediated hydrogen atom transfer and subsequent trapping of alkyl radicals by acylphosphonates.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Thiago Anjos, Elba L. L. Gutterres, Daniela A. A. Barancelli, Roberta Cargnelutti, Benhur Godoi, Thiago Barcellos, Ricardo F. F. Schumacher
Summary: A synthetic method for organochalcogen-functionalized chromenones has been developed using diorganyl dichalcogenides and alkynyl aryl ketones. Selectfluor(R) mediates the cyclization/organochalcogenation reactions under mild and open-to-air conditions. The versatile methodology allows for the synthesis of organochalcogen-substituted thiochromenone and isocromenone derivatives.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Organic
Takuya Suga, Ryusei Takada, Shoma Shimazu, Mizuki Sakata, Yutaka Ukaji
Summary: In this study, Ti-mediated homolytic C-O bond cleavage was utilized for cascade radical-ionic reactions. Benzyl alcohols were treated with TiCl4(col) (col =2,4,6-collidine) and Mn powder to generate benzyl radicals, followed by their reaction with 2-carboxyallyl acetates and subsequent elimination of the acetoxy group to form alpha,beta-unsaturated carbonyl compounds with exclusive (E)-stereoselectivity. The simplicity of the procedure and its wide substrate scope provide a solution to the associated drawbacks of the reactions.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Anurag Noonikara-Poyil, Hui Cui, Andrey A. Yakovenko, Peter W. Stephens, Rui-Biao Lin, Bin Wang, Banglin Chen, H. V. Rasika Dias
Summary: A newly discovered copper compound shows exceptional selectivity and purity in separating C2H4 /C2H6 gas mixtures, offering a promising alternative to traditional distillation methods.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Liangkun Pan, Zhihai Ke, Ying-Yeung Yeung
Summary: In this study, a catalytic vicinal dioxygenation of olefins with hypervalent iodine reagents using Lewis bases as catalysts was reported. The conditions are mild and compatible with various functional groups.
Article
Chemistry, Organic
Guo-Qing Cui, Jing-Cheng Dai, Yan Li, Yuan-Bo Li, Duo-Duo Hu, Kang-Jie Bian, Jie Sheng, Xi-Sheng Wang
Summary: The first example of copper-catalyzed ring-opening, enantioselective arylation of cyclic ketoxime esters has been developed with high yield and excellent enantioselectivity. The side-arm bis(oxazoline) ligand plays a significant role in this asymmetric catalytic transformation, providing an efficient route to construct diverse chiral omega,omega-diaryl alkyl nitriles. This synthetic method also demonstrates its utility in further derivatizing the omega,omega-diaryl alkyl nitrile to the corresponding amide.
Article
Chemistry, Organic
Akira Matsumoto, Zhe Wang, Keiji Maruoka
Summary: A new approach for ester activation via a radical-mediated process enabled by a copper/Selectfluor system is described here. This method allows for the conversion of para-methoxybenzyl esters into acyl fluorides, which can be directly used in the one-pot synthesis of amides and peptides. The method has been successfully applied to the iterative formation of sterically hindered amide bonds as a proof of concept.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Feifei Qi, Wei Zhang, Yingying Xue, Ce Geng, Xuenian Huang, Jia Sun, Xuefeng Lu
Summary: The study elucidates a revised mechanism for anthraquinone ring-opening through gene disruption, enzymatic analysis, and O-18 chasing experiments. It confirms the roles of GedF in reducing the keto group at C-10 and GedK in cleaving the C-10-C-4a bond in questin hydroquinone. This proposed bi-enzyme catalytic and dioxygenation-mediated reaction demonstrates universality in anthraquinone biosynthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Muyang Yang, Wen Shao, Lin Zuo, Jiajia Wang, Yongzhuo Xu, Guojiang Mao, Guo-Jun Deng
Summary: A metal-free, highly site-selective trifluoromethylaminoxylation of activated and unactivated olefins was developed, allowing direct access to diverse β-trifluoromethyl trisubstituted hydroxylamines, tertiary alcohols, isoxazolines, isoxazolidines, and amino alcohols. The reaction proceeds through a SET process between hydroxylamine and a hypervalent iodine-CF3 reagent, generating two free radicals for regio- and diastereoselective addition to alkenes. The synthetic potential of the method was demonstrated through the late-stage functionalization of the products and various postreaction modifications.
Article
Chemistry, Organic
Yang Zheng, Qing-Yun Yang, Lu-Yan Wu, Xin-Yue Zhu, Ming-Jing Ge, Hao Yang, Shi-Yu Liu, Fei Chen
Summary: This novel method utilizes N-hydroxyphthalimide and its analogues as transient nitroxyl-radical precursors and TEMPO+BF4- as both the oxidant and source of persistent nitroxide to achieve regioselective vicinal dioxidation of alkenes under transition metal and organic peroxide free conditions. It efficiently synthesizes structurally important dioxidation products from simple alkenes and complex bioactive molecule derivatives.
Article
Chemistry, Multidisciplinary
Nicholas L. Reed, Grace A. Lutovsky, Tehshik P. Yoon
Summary: This study demonstrates that Cu(II)-mediated radical-polar crossover enables efficient photocatalytic oxidative heterofunctionalization reactions between bulky alkenes and various nucleophilic partners. It shows that Cu(II) salts are ideal terminal oxidants for photoredox applications, and the combination of photocatalytic substrate activation and Cu(II)-mediated radical oxidation can address challenges in catalytic oxidation chemistry.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Multidisciplinary Sciences
Qinglong Shi, Meichen Xu, Rui Chang, Devenderan Ramanathan, Beatriz Penin, Ignacio Funes-Ardoiz, Juntao Ye
Summary: A metal-free platform using peptide- or sugar-derived chiral thiols and deuterium oxide enables asymmetric open-shell deuteration at non-benzylic positions. This approach allows for multiple types of deuterofunctionalization reactions of exocyclic olefins and achieves high levels of enantioselectivity and deuterium incorporation.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Wenbin Shang, Fengyuan Peng, Qianlang Feng, Fei Fang, Zhiqiang Pan, Xu Ji, Chengfeng Xia
Summary: An efficient and practical strategy for the nitrogen-centered radical mediated alpha-sulfonimidation of carbonyl compounds has been established. This strategy enables the sulfonimidation of enol esters to alpha-sulfonimide ketones under ambient conditions, and offers a convenient method for reacting with a diverse range of aromatic and aliphatic ketones with multiple structures. Additionally, it allows for stereoselective alpha-sulfonimidation in complex natural products when a bulky leaving group is employed.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Multidisciplinary Sciences
Nian Li, Jinhang Li, Mingzhe Qin, Jiajun Li, Jie Han, Chengjian Zhu, Weipeng Li, Jin Xie
Summary: This article reports a practical, highly selective and cost-effective hydrogen/deuterium exchange method for unactivated C(sp(3))-H bonds, using photocatalysis and hydrogen atom transfer catalysis. The reaction, using easily prepared PMP-substituted amides as nitrogen-centered radical precursors, leads to selective deuterium incorporation in a wide range of structurally diverse amides, achieving high yields and excellent selectivity.
NATURE COMMUNICATIONS
(2022)
