Article
Chemistry, Multidisciplinary
Matthew R. Lasky, Tolani K. Salvador, Sukrit Mukhopadhyay, Matthew S. Remy, Thomas P. Vaid, Melanie S. Sanford
Summary: This report describes the development of a photochemical method for C(sp(2))-H pyridination that leverages the photoexcitation of electron donor-acceptor (EDA) complexes. The reaction results in aryl radical cation intermediates that can be trapped with pyridine nucleophiles under aerobic conditions. This approach eliminates the need for an exogenous photocatalyst and is cost-effective.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Robert D. Riley, Blake S. N. Huchenski, Karlee L. Bamford, Alexander W. H. Speed
Summary: This study demonstrates that diazaphospholene hydrides can be regenerated by the combination of phenylsilane and alkali metal salts, enabling catalytic radical reactions of aryl iodides. The method is not only applicable to aryl iodides, but can also be extended to aryl bromides, which benefit from visible light irradiation. Additionally, intermolecular radical hydroarylation reactions with arenes, thiophenes, and a pyridine have been successfully achieved.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Chungang Li, Mingli Zhong, Zheng Zeng, Yiqiu Deng, Lanyu Li
Summary: An iridium-catalyzed hydrogen transfer strategy allows for the straightforward synthesis of tetrahydropyridine derivatives, offering high efficiency and environmental friendliness.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Xiang-Kui He, Juan Lu, Hai-Bing Ye, Lei Li, Jun Xuan
Summary: A novel strategy for generating acyl radicals through direct photoexcitation of benzothiazolines has been developed, enabling their functionalization in chemical reactions. The acyl radical species formed can react with quinoxalin-2-ones or isonitriles to synthesize biologically important compounds such as phenanthridines. This strategy can also be applied for modifying natural products and drug-based complex molecules containing quinoxalin-2-ones.
Article
Chemistry, Multidisciplinary
Grant J. Sherborne, Paul Kemmitt, Callum Prentice, Eli Zysman-Colman, Andrew D. Smith, Charlene Fallan
Summary: This study developed a light-mediated cyclisation method for the selective synthesis of tetrahydroquinolines or quinoline derivatives. The method is efficient, atom economical, and tolerant to functional groups, including azaarene-bearing substrates.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Christina Jaeger, Mona Haase, Katja Koschorreck, Vlada B. Urlacher, Jan Deska
Summary: Biocatalytic oxidation of acylated hydroxylamines enables selective introduction of nitrogen functionalities by activating allylic C-H bonds. Utilizing laccases or oxidase/peroxidase couple with air as the oxidant, acylnitroso species are generated under mild aqueous conditions. These reactive intermediates undergo C-N bond formation through an ene-type mechanism, providing high yields in both intramolecular and intermolecular enzymatic aminations. Investigations on different pathways and labelling studies provide insight into the promiscuity of oxidoreductases as catalysts for nitroso-based transformations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Kensuke Kiyokawa, Keisuke Jou, Satoshi Minakata
Summary: A new transition-metal-free method using t-BuOI or NIS was reported for the construction of 1,3-diamine structures, enabling secondary non-benzylic and tertiary C-H amination reactions to proceed. Mechanistic investigations revealed different pathways for amination reactions using t-BuOI or NIS.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Rok Narobe, Kathiravan Murugesan, Simon Schmid, Burkhard Koenig
Summary: This study presents a metal-free system based on iodine (I/III) catalytic manifold that can generate carbenium ion intermediates at electronically disfavored positions. The system exhibits unusually high reactivity due to the complexation of iodine (III) intermediates with BF3. Detailed mechanistic investigations suggest two possible pathways for the decarboxylative Ritter-type amination protocol.
Article
Chemistry, Multidisciplinary
Byeongseok Kweon, Changha Kim, Seonyul Kim, Sungwoo Hong
Summary: An efficient strategy for remote C-H pyridylation of hydroxamates with excellent ortho-selectivity has been developed by designing new photon-absorbing O-aryl oxime pyridinium salts. The photoexcitation of oxime pyridinium intermediates generates iminyl radicals via photolytic N-O bond cleavage, allowing for the installation of pyridyl rings at the gamma-CN position. This novel synthetic approach offers advantages in terms of efficiency, simplicity, and broad functional group tolerance under mild and metal-free conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Guang Yang, Zhicheng Xiong, Hongsheng Nie, Meiqin He, Qiong Feng, Xuan Li, Huabin Huang, Shoucai Wang, Fanghua Ji, Guangbin Jiang
Summary: With control by N1-substituents, switchable divergent C-H functionalization reaction of quinoxalin-2(1H)-ones was achieved for the synthesis of (Z)-enaminones and furo[2,3-b]quinoxalines using copper catalyst and oxidant. The method features mild reaction conditions, readily available materials, and a broad substrate scope, and the desired products showed excellent antitumor activity against A549, HepG-2, MCF-7, and HeLa cells.
Article
Chemistry, Multidisciplinary
Wei Zhao, Wenji Wang, Huan Zhou, Qishan Liu, Zhiqing Ma, Haizhou Huang, Mingxin Chang
Summary: A one-pot asymmetric hydrogenation of pyridines with subsequent N-alkylation using a traceless Bronsted acid activation strategy is reported. The reaction exhibits high stereoselectivity and can be used to synthesize indolizidines and quinolizidines. Experimental and theoretical studies reveal that chloride anion and noncovalent interactions play important roles in determining the stereoselectivity of the reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Lorand Bonda, Daniel J. J. Valles, Tillmann L. L. Wigger, Jan Meisner, Adam B. B. Braunschweig, Laura Hartmann
Summary: Controlled radical polymerizations (CRPs) are an important method for obtaining uniform and defined molecular weight polymers with complex composition and architecture. A new controlled and light-initiated radical polymerization using thiol initiators and an Ir-photocatalyst is introduced. Different reaction parameters are studied for their importance in achieving controlled characteristics of polymerization, such as low dispersity and control of molecular weights, and the ability to access block copolymers easily. The proposed mechanism for thiol-induced, light-activated, controlled radical polymerization (TIRP) involves the formation of dormant species and their equilibrium with the active polymer chain end, which is dependent on light and catalyst. TIRP expands the range of controlled and light-initiated polymerization methods by its mild conditions and the ability to grow polymers from a variety of readily available thiols.
Article
Chemistry, Applied
Pol Hernandez-Llado, Kilian Garrec, Daniel C. Schmitt, Jonathan W. Burton
Summary: In this study, a metal-free, visible light-mediated cyclization of malonates onto 5-ring heteroaromatics is reported. The method eliminates the need for transition metals or toxic tin reagents and instead utilizes iodomalonates as key intermediates. The annulated products are obtained in good yields (46-94%) without the use of external catalysts.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Wongyu Lee, Dongwook Kim, Sangwon Seo, Sukbok Chang
Summary: In this study, a polar-radical relay strategy is reported for the alpha-C-H amination of cyclic amines using N-chloro-N-sodio-carbamates. The strategy involves the in situ generation of a cyclic iminium intermediate using N-iodosuccinimide (NIS) as an oxidant, followed by a series of polar and radical reactions to achieve controlled C-N bond formation. The method provides a facile and regioselective access to a broad range of alpha-amino cyclic amines and demonstrates excellent applicability for functionalization of biologically relevant compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Prithwish Ghosh, Na Yeon Kwon, Youjung Byun, Neeraj Kumar Mishra, Jung Su Park, In Su Kim
Summary: In this study, a cobalt(II)-catalyzed method for C-H alkylation and acylation of N-heterocycles using 1,4-dihydropyridines (DHPs) as alkylating and acylating agents was reported. The combination of KBrO3 and a Co(II) catalyst successfully generated alkyl and acyl radicals from DHPs. This method was applicable to various heterocycles and demonstrated selectivity in modifying drug candidates and synthesizing bioactive molecules on a gram scale.
Article
Chemistry, Organic
Kun Wang, Saisai Niu, Xin Guo, Weijun Tang, Dong Xue, Jianliang Xiao, Huaming Sun, Chao Wang
Summary: This research discovers a new method to convert prochiral racemic allylic alcohols to enantioenriched chiral alcohols bearing adjacent stereocenters using a diamine diphosphine Ru complex and tBuOK catalyst. The protocol exhibits a wide substrate scope and high selectivities, and can be applied to the synthesis of enantioenriched chromane and indane compounds.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Xiaohui Zhang, Wei Ma, Jinyu Zhang, Weijun Tang, Dong Xue, Jianliang Xiao, Huaming Sun, Chao Wang
Summary: The asymmetric hydroalkylation of racemic allylic alcohols has been developed for the synthesis of chiral amino acid derivatives with two remote chiral centers by borrowing hydrogen catalysis. The stereoselectivities are controlled by a single chiral Ru catalyst via a dynamic kinetic asymmetric transformation process and an interesting diastereoselectivity amplification process of the product.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Yonggang Yan, Jinjin Sun, Gang Li, Liu Yang, Wei Zhang, Rui Cao, Chao Wang, Jianliang Xiao, Dong Xue
Summary: A light-promoted Ni-catalyzed cyanation reaction using 1,4-dicyanobenzene as a cyanating agent is described. Various aryl bromides, chlorides, and druglike molecules are converted to their corresponding nitriles (65 examples). Mechanistic studies reveal that under irradiation, the Ni(II)(dtbbpy)(p-C6H4CN)(CN) oxidative addition product undergoes homolytic cleavage of the Ni-aryl bond to generate an aryl radical and a Ni(I)-CN species, which initiates subsequent cyanation reactions.
Article
Chemistry, Multidisciplinary
Xiaoyun Wu, Wei Ma, Weijun Tang, Dong Xue, Jianliang Xiao, Chao Wang
Summary: A Fe-catalyzed amidation of allylic alcohols with chiral tert-butylsulfinamide has been developed for the synthesis of chiral sulfinamide olefin derivatives. The reaction proceeds under mild conditions with water as the only by-product.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Geyang Song, Ding-Zhan Nong, Jing-Sheng Li, Gang Li, Wei Zhang, Rui Cao, Chao Wang, Jianliang Xiao, Dong Xue
Summary: The Buchwald-Hartwig C-N coupling reaction is widely used in medicinal chemistry. Ni-based catalysts have attracted great attention due to their lower cost and higher reactivity towards less reactive aryl chlorides. However, there is currently no universal Ni catalytic system available for the coupling of electron-rich and electron-poor aryl halides with primary and secondary alkyl amines. In this study, a Ni(II)-bipyridine complex is reported to catalyze efficient C-N coupling of aryl chlorides and bromides with various primary and secondary alkyl amines under direct excitation with light. The feasibility and applicability of this protocol in organic synthesis are demonstrated with over 200 examples.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Yuxuan Liu, Qi Luo, Qian Qiang, Hua Wang, Yangming Ding, Chao Wang, Jianliang Xiao, Changzhi Li, Tao Zhang
Summary: The sustainable synthesis of quinoxaline derivatives from lignin beta-O-4 model compounds under transition-metal-free conditions has been achieved for the first time in this study. Mechanistic studies showed that this transformation involves highly coupled cascade steps. With this method, a wide range of functionalized quinoxalines, including an important drug compound, were successfully synthesized, demonstrating the potential application of lignin in pharmaceutical synthesis.
Article
Chemistry, Organic
Liu Yang, Yonggang Yan, Ni Cao, Jing Hao, Gang Li, Wei Zhang, Rui Cao, Chao Wang, Jianliang Xiao, Dong Xue
Summary: A highly efficient hydroxylation of (hetero)aryl halides using water as a hydroxyl source via Ni catalysis promoted by PhSiH3 under thermal catalysis is described. This methodology provides a general procedure for the synthesis of diverse multifunctional pharmaceutically phenols and polyphenols, some of which are challenging to be synthesized using literature methods. Mechanism studies reveal that the addition of PhSiH3 leads to the generation of active Ni(I) species, which catalyze the hydroxylation through a Ni(I)-Ni(III) pathway.
Article
Chemistry, Physical
Geyang Song, Ding-Zhan Nong, Qi Li, Yonggang Yan, Gang Li, Juan Fan, Wei Zhang, Rui Cao, Chao Wang, Jianliang Xiao, Dong Xue
Summary: This study demonstrates an easy, efficient, and economic method for synthesizing anilines. By directly exciting light, the amination of aryl halides with ammonium salts can be catalyzed using a Ni(OAc)2-bipyridine complex, allowing a broad range of aryl chlorides and bromides to be converted into primary (hetero)arylamines without the need for an external photosensitizer. The photoinduced generation of Ni(I)-bipyridine species is believed to play a key role in this catalytic cycle.
Article
Chemistry, Multidisciplinary
Wang Miao, Jinyu Zhang, Yanyan Yang, Weijun Tang, Dong Xue, Jianliang Xiao, Huaming Sun, Chao Wang
Summary: The transformation of alcohols into value-added products is of great importance, and this study achieved the selective functionalization of a sp(3) C-H bond on the alkyl side chain of an alcohol, expanding the chemical space of alcohols using the borrowing hydrogen strategy.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yuan Gao, Zhijun Wang, Xinyu Zhang, Min Zhao, Shuai Zhang, Chao Wang, Liang Xu, Pengfei Li
Summary: In this study, novel chiral half-sandwich iridium catalysts were designed and synthesized, which enabled the preparation of a broad range of α-chiral (hetero)aryl amines with high yield and enantioselectivity. The optimized catalyst and azeotropic mixture of formic acid and triethylamine were used as the hydrogen source under mild and operationally simple conditions. This work introduced an effective chiral catalyst for the simplified synthesis of medicinally important chiral amines, and also provided a rare example of robust enantioselective transition-metal catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Geyang Song, Qi Li, Ding-Zhan Nong, Jiameng Song, Gang Li, Chao Wang, Jianliang Xiao, Dong Xue
Summary: This paper describes a photochemical C-N coupling reaction of less reactive aryl chlorides with primary and secondary amides using a Ni catalyst without an external photocatalyst. The reaction proceeds under light irradiation (390-395 nm) with a soluble organic amine as the base, resulting in the successful synthesis of a wide range of N-aryl amides from (hetero)aryl chlorides. Mechanistic studies suggest that the amidation occurs via a Ni(I)-Ni(III) catalytic cycle.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Fei Li, Weikang Xiong, Geyang Song, Yonggang Yan, Gang Li, Chao Wang, Jianliang Xiao, Dong Xue
Summary: A general and efficient photochemical C-N coupling method for (hetero)aryl chlorides with hydrazides is presented. The reaction is catalyzed by a Ni(II)-bipyridine complex and does not require an external photosensitizer, making it highly practical. This method demonstrates a wide substrate scope (54 examples) and excellent functional group tolerance, and has been successfully applied to the synthesis of rizatriptan.
Article
Chemistry, Multidisciplinary
Yonggang Yan, Gang Li, Jiani Ma, Chao Wang, Jianliang Xiao, Dong Xue
Summary: This paper reports the photoinduced generation of highly reactive ketyl radicals and their application in C-C coupling, without the need for any external photocatalyst.
Article
Chemistry, Multidisciplinary
Suya Cui, Xiaoyun Wu, Wei Ma, Weijun Tang, Huaming Sun, Jianliang Xiao, Dong Xue, Chao Wang
Summary: An iron-catalyzed coupling reaction between fl-amino alcohols and allylic alcohols for the synthesis of 3,4-dihydro-2H-pyrrole derivatives has been developed. Mechanistic studies suggest that the reaction involves iron-catalyzed dehydrogenative coupling and C-C bond cleavage processes.
GREEN SYNTHESIS AND CATALYSIS
(2021)
Article
Chemistry, Organic
Jennifer Smith, Aysecik Kacmaz, Chao Wang, Barbara Villa-Marcos, Jianliang Xiao
Summary: A series of chiral cyclometalated iridium complexes were synthesized and studied for asymmetric transfer hydrogenation reactions using formic acid as the hydrogen source, showing different activities and enantioselectivities, with the most effective ones achieving up to 63% ee in asymmetric reductive amination of ketones and 77% ee in reduction of pyridinium ions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
