Article
Chemistry, Organic
Linjuan Jiang, Hui Hu, Yuanhong Liu
Summary: A copper-catalyzed regioselective C-2 alkenylation of quinoline N-oxides with alkynes and pinacol diborane has been developed, providing efficient access to a wide variety of deoxygenated 2-alkenyl quinolines with good functional group tolerance, especially with unsymmetrical alkynes such as aryl(alkyl)acetylenes and enynes.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Bartlomiej Sadowski, Binbin Yuan, Zhipeng Lin, Lutz Ackermann
Summary: In this study, electrocatalytic peri C-H alkenylation of 1-naphthols was achieved using rhodium(III) catalysis under constant current electrolysis conditions. This strategy offers a wide scope, good functional group tolerance, and high site- and stereoselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Nahiane Pipaon Fernandez, Gregory Gaube, Kyla J. Woelk, Mathias Burns, Damian P. Hruszkewycz, David C. Leitch
Summary: We present a new method for direct C-C bond formation using tandem C-O/C-H activation mediated by palladium catalyst. This approach allows for base-free direct C-H alkenylation by combining C-O oxidative addition at enol pivalates and concerted metalation-deprotonation of functionalized heterocycles. Mechanistic studies show that C-O oxidative addition is reversible and C-H activation occurs directly from the Pd(II) C-O oxidative addition product. In situ P-31 NMR spectroscopy reveals that (Cy3P)(2)Pd-(alkenyl)(OPiv) species is the predominant catalyst resting state during the reactions.
Article
Chemistry, Multidisciplinary
Zi-Chen Wang, Rui-Tao Li, Qiang Ma, Jia-Yi Chen, Shao-Fei Ni, Ming Li, Li-Rong Wen, Lin-Bao Zhang
Summary: A method for electrochemically driven Rh(iii)-catalyzed regioselective annulation of arenes with alkynes has been established, which avoids the use of external oxidant, proceeds under mild and green conditions, and is compatible with a broad range of substrates including drugs. This method is operationally simple and efficient in aqueous solution in air.
Article
Chemistry, Organic
Priyambada Prusty, Subramanian Jambu, Masilamani Jeganmohan
Summary: A mild, convenient, and effective Rh(III)-catalyzed site-selective C2-alkenylation of N-carboxamide indoles with unactivated alkenes at room temperature has been described. The reaction was successfully demonstrated with a variety of indole N-carboxamides and unfunctionalized/functionalized unactivated alkenes, and a possible reaction mechanism involving C-H activation/insertion/internal oxidation followed by protonation has been proposed and supported by deuterium-labeling studies.
Article
Chemistry, Organic
Yu Ru-Jian, Zhang Chun-Yan, Zhou Xiang, Yan-Shi Xiong, Xue-Min Duan
Summary: This study describes a copper-catalyzed direct C-H chalcogenation of N-aryl-azaindoles with disulfides, showcasing high functional group tolerance and excellent regioselectivity in the efficient preparation of a wide range of ortho-sulfenylation-7-azaindoles.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Zhangqiang Yan, Zhen Zhang, Tao Wen, Lihua Ye, Bo Jin, Chihong Zhang, Wenkun Wang, Zhong-Ning Chen, Hu Cai
Summary: Direct alpha-C(sp(3))-H alkylation of hydroaminoalkylation (HAA) catalyzed by (BuOK)-Bu-t/DMSO/O-2 from alpha-aryl benzylamines with styrenes was reported. The reaction provided selectively substituted amines and N-heterocycles under mild conditions. Mechanism studies revealed that alpha-aminoalkyl radicals acted as intermediates and hydrogen atom transfer (HAT) played a crucial role in the (BuOK)-Bu-t/DMSO/O-2 system.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Tamilarasu Murugesan, Chinraj Sivarajan, Chithra Mohan Jayakumari, Rajat Kumar Singh, Sivaranjana Reddy Vennapusa, Alagiri Kaliyamoorthy
Summary: In this study, a straightforward access to C2-biarylated indole derivatives was achieved through palladium-catalyzed C-H activation strategy, with yields ranging from 24% to 92%. The UV/visible absorption and fluorescence properties of the resulting products were explored, showing that these compounds may exhibit atropisomerism at room temperature based on calculated dihedral angle and rotational barrier values.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Jinghao Zhang, Yang Chen, Jing Sun, Jingyun Wang, Mingdong Zhou
Summary: A palladium-catalyzed direct alkenylation method for alkyl chain-substituted tetrathienoacenes has been developed under mild conditions. This efficient and viable approach allows for the synthesis of various dialkenylated tetrathienoacenes using different functionalized alkenes as coupling substrates.
Article
Chemistry, Organic
Anurag Singh, Arnab Dey, Kuntal Pal, Om Prakash Dash, Chandra M. R. Volla
Summary: A novel method for achieving C4 chlorination/bromination or acetoxylation of indoles by transient directing group (TDG) assistance has been disclosed in this study. The use of inexpensive CuX2 as the halide source highlights the practicality of this approach.
Article
Chemistry, Organic
Chuan-Chong Peng, Li-Jun Wu, Shao-Feng Pi
Summary: An efficient palladium-catalyzed difunctionalization/dearomatization of N-benzylacrylamides with alpha-carbonyl alkyl bromides as alkyl radical precursors was described in this study. Various alpha-carbonyl alkyl bromides, including alpha-bromoalkyl esters and ketones, smoothly reacted to provide important azaspirocyclohexadienones in moderate to excellent yields. Additionally, mechanistic studies indicated that the reaction proceeded via a radical pathway.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Qiang Wang, Zilong Yan, Dong Xing
Summary: We report a nickel(0)-catalyzed linear-selective hydroarylation reaction using a bifunctional temporary directing group strategy. Excellent linear selectivity is achieved through imino-assisted six-membered metallacycle formation.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Physical
Shrikant M. Khake, Ken Yamazaki, Yusuke Ano, Naoto Chatani
Summary: This study reports a branch-selective C-H alkenylation method using an iridium catalyst with alkenes, suitable for aniline derivatives containing a pyrimidine-directing group, offering a broad substrate scope and tolerating various functional groups. The origin of branch selectivity was investigated using density functional theory calculations.
Article
Multidisciplinary Sciences
Xiaochen Wang, Rongxin Yang, Binbing Zhu, Yuxiu Liu, Hongjian Song, Jianyang Dong, Qingmin Wang
Summary: Here, the authors describe a multicatalytic method for the synthesis of beta, gamma-unsaturated ketones via allylic acylation of alkenes. The method combines N-heterocyclic carbene catalysis, hydrogen atom transfer catalysis, and photoredox catalysis for cross-coupling reactions. The method shows excellent site selectivity and could be used for the synthesis of diverse beta, gamma-unsaturated ketones using carboxylic acids and olefins as substrates.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Mingda Li, Yangbin Jin, Yupeng Chen, Wanqing Wu, Huanfeng Jiang
Summary: This paper reports a new catalytic system for the efficient oxidative amination of unactivated olefins with primary aliphatic amines, leading to the formation of secondary allylic amines. The reaction proceeds through allylic C(sp3)-H activation and nucleophilic amination. The utility of this method is demonstrated in the late-stage modification and streamlined synthesis of drug molecules.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Zhiheng Li, Danran Li, Huaming Xiang, Jian Huang, Yinuo Zheng, Cuiju Zhu, Xiuling Cui, Chao Pi, Hao Xu
Summary: In this study, a highly enantioselective propargylic substitution reaction of anthrones with propargylic esters using copper salts with chiral N, N, P-ligand was disclosed. This strategy shows broad substrate compatibility, mild reaction conditions, excellent yields with remarkable enantioselectivity, and enables the synthesis of diverse products.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Di Hu, Chao Pi, Wei Hu, Xiliang Han, Yangjie Wu, Xiuling Cui
Summary: In this study, a Ru(III)-catalyzed annulation reaction of 2-aminoaromatic aldehydes (ketones) and isoxazoles to produce diverse 3-cyanoquinolines has been developed. The isoxazole served as a cyclization reagent and a non-toxic cyano source via N-O bond cleavage, leading to the formation of variously substituted (especially 6- or 7-substituted) quinolines. This efficient and versatile method offers wide functional group compatibility and avoids the use of toxic cyano sources. Furthermore, the synthesized 3-cyanoquinoline can undergo further chemical transformations to yield valuable skeletons, demonstrating its potential in synthetic applications.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Haopeng Xu, Chao Pi, Yangjie Wu, Xiuling Cui
Summary: An efficient multi-component reaction has been developed for the synthesis of 2,3-disubstituted tetrahydrofurans in a one-pot manner, providing a wide array of alpha-indole-beta-sulfonyl tetrahydrofurans in good yields with excellent selectivity, while avoiding the use of various additives and transition metals as catalysts.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Applied
Jie Ren, Liu Yang, Chao Pi, Xiuling Cui, Yangjie Wu
Summary: In this study, a rhodium(III)-catalyzed divergent C-H bond functionalization of N-aryl amidines with iodonium ylides was described. Carbazolones and zwitterionic salts were synthesized through intermolecular annulation and intramolecular proton transfer under different reaction conditions. This protocol is simple to perform and can tolerate a variety of functional groups, making it practically useful for post-modification of pharmaceutical molecules.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Wenxiang Wang, Chao Pi, Xiuling Cui, Yangjie Wu
Summary: A TBAI-catalysed [4+4]-cyclization reaction was developed for the synthesis of oxa-bridged eight-membered heterocycles from anthranils and hydrazones. Mechanistic studies showed the in situ generation of vinyldiazenes from hydrazones, followed by an aza-Michael addition and subsequent annulation. This strategy overcomes the limitations of anthranils in organic chemistry and provides a high efficiency and atom economical approach.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Jian Shen, Bo Cui, Junwei Huang, Shenghui Lin, Xiuling Cui
Summary: A highly efficient strategy to construct benzo[d][1,3]diazepines via selective C-H bond activation of N-aryl amidines and coupling with alkynyl cyclobutyl acetates was successfully achieved by Ru-II-catalyzed [5+2] cyclization. This protocol features excellent regioselectivity, wide substrate tolerance, and mild reaction conditions, which might be potentially applied in the discovery of lead compounds for the development of new drugs.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Xuelin Yue, Yijie Gao, Junwei Huang, Yadong Feng, Xiuling Cui
Summary: An efficient method for the synthesis of N substituted indenoisoquinolinones has been developed via rhodium(III)-catalyzed C- H bond activation and subsequent [4 + 2] cyclization. The reaction uses 2-phenyloxazolines and 2-diazo-1,3-indandiones as starting materials and proceeds through C-H functionalization, intramolecular annulation, elimination, and ring opening in one pot under mild conditions, yielding a series of indeno[1,2-c]isoquinolinones with up to 93% yield. This method demonstrates excellent atom-and step-economy and provides a novel strategy for the synthesis of N substituted indenoisoquinolinones and their study of biological activities.
Article
Chemistry, Organic
Jie Ren, Chao Pi, Xiuling Cui, Yangjie Wu
Summary: Transition metal-controlled divergent annulation reactions of azomethine imines with iodonium ylides via C centered [1,2]-rearrangement have been developed. The azomethine imino group, as a switchable and transient directing group (DG), underwent intramolecular nucleophilic addition and in situ generated bicyclic diaziridine, which facilitated the C-centered [1,2]-rearrangement and subsequent divergent annulations in the presence of different metal complexes as the catalysts. The benzo[c]chromen-1-one and pyrano[de]isochromene scaffolds could be independently constructed with Rh(III) and Ru(II), respectively. It was worth noting that the azomethine imino group was employed first as the switchable DG through rearrangement progress.
Article
Chemistry, Organic
Xinxin Yan, Chao Pi, Xiaofan Cui, Xiuling Cui, Yangjie Wu
Summary: A novel approach to construct multiple heterocycles with high selectivity has been developed through Rh(III)-catalyzed two-or three-component cyclization reaction using simple and readily available starting materials: N-methoxybenzamides, 2-butyne biscarbonate, and maleimides. This methodology provides an efficient strategy for the synthesis of diverse and complicated heterocycles in a one-pot manner, and it exhibits excellent features of extremely mild reaction conditions, easy operation, excellent regioselectivity, and good functional group compatibility.
Review
Chemistry, Applied
Xiaofan Cui, Remi Chauvin, Chao Pi, Yangjie Wu, Xiuling Cui
Summary: This review presents recent progress in the use of vinylene carbonate as a reactant in transition metal-catalyzed C-H bond activation/cyclization reactions. By analyzing and comparing different reaction models, it highlights the advantages of using vinylene carbonate as a surrogate for ethynol and other reactants, and discusses related mechanisms and synthetic applications.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Xiang Zhao, Junwei Huang, Yadong Feng, Xiuling Cui
Summary: The efficient rhodium(III)-catalysed C-H activation of 3-aryl-1-H-indazoles with readily accessible vinylethylene carbonate has been reported. Allyl alcohol substituted 3-aryl-1-H-indazoles were obtained with broad functional groups tolerance and favorable stereoselectivity. Significant to note is the selective activation of C-H and C-O bonds in a one-pot manner, with the release of CO2 as the only by-product and avoiding the need for external oxidants. This protocol provides a powerful approach for the post stage C-H allylation of indazole-based substrates.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Paulo J. Costa, Frederico F. Martins, Chao Pi, Xiuling Cui, Maria Jose Calhorda
Summary: PdCl2 was found to catalyze the C-H activation of QOs through the formation of a metallacycle or an η(3)-QO complex. Activation at the C8 position resulted in a lower energy barrier compared to activation at the C2 position. The presence of water led to C8-H activation and the formation of 2-quinolinones.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Junwei Huang, Xuelin Yue, Yijie Gao, Yadong Feng, Xiuling Cui
Summary: A mild and efficient method for the synthesis of structurally diverse N/O spiroheterocycles has been developed via Rh(iii)-catalyzed [3+3] cascade spiroannulation of benzoxazines with 1-diazonaphthalen-2(1H)-ones. The desired spirooxazine-pyrans could be obtained in up to 99% yields at room temperature within 30 min. This transformation involves C-H activation, tautomerization, and intramolecular nucleophilic addition in a one-pot manner. In addition, this catalytic system shows high efficiency, atomic economy, wide functional group tolerance, and extremely mild reaction conditions.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Organic
Yong Wang, Jingyuan Li, Yanyan Li, Chao Pi, Yangjie Wu, Xiuling Cui
Summary: In this study, a de novo organocatalyzed enantioselective construction of hydantoins from simple urea and glyoxal is reported. It is proposed that a chiral phosphoric acid (CPA) catalyzed [3 + 2] heteroannulation/enantioselective Heyns rearrangement is involved in this transformation. The Heyns rearrangement proceeds smoothly via a proton-transfer process involving an enol intermediate, with CPA serving as a chiral proton-transfer shuttle to control the enantioselectivity.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Jie Ren, Chao Pi, Xiuling Cui, Yangjie Wu
Summary: The successful introduction of aryl moieties into heterocyclic scaffolds through photocatalytic direct C(sp(2))-H arylation has been achieved, demonstrating a wide substrate scope and excellent tolerance of functional groups.
