Article
Chemistry, Multidisciplinary
Zhenhua Xu, Ning Xian, Hongbiao Chen, Guo-Jun Deng, Huawen Huang
Summary: This study introduces a copper-based catalytic system for the efficient cyclization of methylketoximes and alkynals, offering a viable approach to synthesize 2-acylpyrroles with a broad range of compatible functionalities. Additionally, it suggests a key acyl migration mechanism that leads to the formation of N-acyl pyrroles or NH pyrroles by further hydrolysis, and also provides an opportunity for a three-component pyrrole assembly by simple addition of carboxylic acid.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Organic
Rajitha Lakshmi Podugu, Varaprasad Bodala, Kumari Yettula, Bharat Kumar Karasala, Siddaiah Vidavalur
Summary: An efficient and facile strategy for the synthesis of symmetrical pyridines has been developed, which provides good to excellent yields. In this strategy, ketoxime acetates and DMFDMA are reacted in the presence of FeCl3 catalyst at 120 degrees C for 6 hours under argon atmosphere. DMFDMA acts as an effective C1 synthon in this protocol. The advantages of this protocol include the use of inexpensive catalysts, no need for additional ligands and additives, and excellent functional group tolerance.
POLYCYCLIC AROMATIC COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Bodala Varaprasad, Karasala Bharat Kumar, Vidavalur Siddaiah, Pulipaka Shyamala, Lekkala Chinnari
Summary: An efficient and concise method for the synthesis of 2,4,6-triphenyl pyridines was developed using copper-catalyzed oxidative decarboxylative coupling, tolerating various functional groups and providing good to excellent yields.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Organic
Gaochen Xu, Huan Yan, Sai Zhang, Qinghuan Wu, Jindian Duan, Kai Guo
Summary: A new method using FeCl2 as catalyst for [4+2] annulation of alpha,beta-unsaturated ketoxime acetates with N-acetyl enamides in batch and flow processes is reported. This strategy features a low-cost catalytic system, use of electron-rich olefins, operational simplicity, and broad substrate scope, providing a facile and efficient access to substituted pyridines in moderate to good yields.
Article
Chemistry, Organic
Xing-Mei Hu, Jing Yang, Jia-Ming Yang, Bi-Na Shao, Rong Huang, Sheng-Jiao Yan
Summary: Here, a novel method is presented for the synthesis of highly functionalized 2,4-diarylpyridines. This method involves a one-pot cascade reaction utilizing alpha,beta-unsaturated ketoxime acetates and enaminones as substrates, encompassing a SET, Michael reaction, oxidation of allyl group carbon, and loss of one proton and one PhNH2. The cascade reaction generates a series of functionalized pyridines, including functionalized asymmetrical 2,4-diarylpyridines. This method provides an efficient alternative to the tedious multi-step syntheses traditionally employed and is suitable for combinatorial and parallel syntheses of pyridine derivatives in a one-pot reaction.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Subhasree Pal, Siuli Das, Subhajit Chakraborty, Subhankar Khanra, Nanda D. Paul
Summary: In this study, a Zn(II)-catalyzed solvent-free sustainable synthesis of tri- and tetra-substituted pyridines was reported. The primary feedstock used was alcohols and NH4OAc served as the nitrogen source. The well-defined air-stable Zn(II)-catalyst, featuring a redox-active tridentate azo-aromatic pincer, was used for the synthesis of a wide variety of unsymmetrical 2,4,6-substituted pyridines by three-component coupling of alcohols with NH4OAc. The reactions proceeded efficiently and produced high yields of the desired products.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Debasmita Mondal, Subhendu Pramanik, Chinmay Chowdhury
Summary: Palladium-catalyzed reactions provide an easy access to desired compounds, and the choice of suitable phosphine ligands is crucial for the success of the reaction.
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, Multidisciplinary
Yilin Li, Kai Yang, Liang Cao
Summary: A novel and efficient copper-catalyzed strategy for the synthesis of diverse pyridines has been reported. Various unsymmetrical 2,6-diarylpyridines can be conveniently obtained by changing different substrates. This method developed a rare copper-catalyzed direct difunctionalization of saturated ketones for the synthesis of nitrogen heterocycles. It has excellent functional group tolerance, readily available raw materials, high chemoselectivity, and broad substrate scope.
Article
Chemistry, Organic
Kun Wang, Hong-Rong Guan, Wen-Long Ren, Hai-Tao Yang, Chun-Bao Miao
Summary: A copper-catalyzed cascade annulation reaction has been developed for the rapid synthesis of spiro-pentacyclic derivatives, forming five C-C/N/O bonds and an angular tricyclic core in one step under very mild conditions with excellent regioselectivity and stereoselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Shuaijie Wu, Shuting Zhang, Jing Sun, Ying Han, Yidong Wang, Chao-Guo Yan, Lei Wang
Summary: A highly efficient Pd-catalyzed carboetherification reaction between beta,gamma-unsaturated ketoximes and propargylic acetates is demonstrated. This method provides a practical protocol for accessing 3,5-disubstituted and 3,5,5-trisubstituted isoxazolines with an allene moiety. The transformation features a broad substrate scope, good functional group tolerance, easy scale-up, versatile transformations, and applications in late-stage drug modification.
Article
Chemistry, Organic
Binsen Rong, Gaochen Xu, Huan Yan, Sai Zhang, Qinghuan Wu, Ning Zhu, Zheng Fang, Jindian Duan, Kai Guo
Summary: An efficient copper-catalyzed annulation of ketoxime acetates with acetoacetanilide has been developed for the synthesis of benzofuro- and benzothieno[2,3-c]pyridines, showing good functional group tolerance and operational simplicity. Mechanistic investigation revealed the involvement of an ionic pathway rather than a radical pathway in the transformation.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Yun-Xuan Tan, Shijia Li, Lijuan Song, Xinhao Zhang, Yun-Dong Wu, Jianwei Sun
Summary: The first geminal hydroborative cyclization of enynes is disclosed in this study. Unlike known hydroborative cyclizations, this reaction adds hydrogen and boron to the same position, leading to a new reaction mode. By using a specific catalyst, a variety of gem-hydroborated bicyclic products with a cyclopropane unit can be rapidly formed from simple enyne substrates. Control experiments and calculations provide important insights into the reaction mechanism. Notably, two competing pathways may operate, depending on the substrate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Xue-Yi He, Zhong-Xia Wang
Summary: The ruthenium(II)-catalyzed reaction between aniline derivatives and allylamines was used to synthesize 2-methylindoles via C-H/C-N bond activation. The most effective directing group is the 4,5-dimethyl pyrimidin-2-yl group attached on the nitrogen atom of anilines, while N-allyl-4-fluoro-N-methylaniline is the optimal allylamine. The cyclization products were obtained in yields ranging from 16% to 96%. The reaction does not require an external oxidant, and a possible mechanism is proposed.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Shujun Cao, Chongchong Ma, Xinjie Teng, Rongshun Chen, Yun Li, Weidong Yuan, Yingguang Zhu
Summary: A novel and efficient synthesis method for fully substituted 1H-imidazoles has been developed through photoredox/copper cocatalyzed domino cyclization of oxime esters, aldehydes, and amines. This method exhibits good functional group tolerance, broad substrate scope, high step economy, high bond-forming efficiency, and the ability for gram-scale synthesis.
ORGANIC CHEMISTRY FRONTIERS
(2022)
