Article
Chemistry, Multidisciplinary
Xiaomin Shu, De Zhong, Yanmei Lin, Xiao Qin, Haohua Huo
Summary: We report a general and modular approach for the direct enantioselective alpha-arylation of saturated azacycles and acyclic N-alkyl benzamides via nickel/photoredox dual catalysis. This method requires no oxidants or organometallic reagents, features broad substrate scope and high enantioselectivities, and is applicable to late-stage diversification of medicinally relevant complex molecules.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Boya Feng, Guodong Zhang, Xu Feng, Yu Chen
Summary: A palladium-catalyzed decarbonylative methylation of aryl carboxylic acids using trimethylboroxine as the methylating reagent is described. The Pd(OAc)(2)/XantPhos system is compatible with a wide range of carboxylic acids and derivatives, including aroyl chloride/fluoride. The successful methylation of bioactive molecules and examples of orthogonal cross-couplings demonstrate the practicality of this method.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Ni-Juan Zhang, Wen-Tao Ma, Jia-Wei Li, Yue-Jin Liu, Ming-Hua Zeng
Summary: An efficient and straightforward synthesis of aryl-substituted biarylphosphines was developed using unprotected amino acids as accelerators in a ruthenium-catalyzed P-directed ortho-C-H arylation reaction. Commercial and inexpensive aryl chlorides were used as effective arylating reagents under solvent-free conditions, with diverse aryl bromides also proven to be effective. The resulting aryl-substituted phosphines exhibited higher catalytic performance in palladium-catalyzed Suzuki coupling compared to their precursors and other substituted phosphines.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Yi-Ming Wei, Xiao-Di Ma, Meng-Fei Wang, Xin-Fang Duan
Summary: Fe-catalyzed difunctionalization of aryl titanates through double C-H activation has been developed. Aryl titanates are arylated via ortho C-H activation, followed by ipso electrophilic trapping of the C-Ti bond. The ortho C-H arylation is promoted by a 1,2-Fe/Ti heterobimetallic arylene intermediate and involves another ortho C-H activation directed by benzamides, esters, and nitriles.
Article
Chemistry, Multidisciplinary
Hongliang Zhao, Chao-Yue Zhao, Lili Chen, Chungu Xia, Xin Hong, Senmiao Xu
Summary: We report the iridium-catalyzed enantioselective C-H borylation of aryl chlorides, which could afford axially chiral biaryls with high enantioselectivities. The method demonstrates high turnover number (TON) and shows potential for synthetic applications in C-B, ortho-C-H, and C-Cl bond functionalization.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Patrick Sand, Bernd Schmidt
Summary: Vinylsulfonamides do not react with acetanilides in Pd-catalyzed oxidative Heck-coupling reactions, but this limitation has been overcome by using a C-H-activation protocol based on Ru-Cu-Ag-catalysis. The Ru-Cu-Ag-catalyzed conditions are more reliable and reproducible compared to Pd-catalyzed C-H-activation. The resulting functionalized styrenyl sulfones and -sulfonamides can serve as starting materials for synthesizing sulfonyl pyrroles and sulfonyl pyrrolo[2,3-c]quinolines.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Patrick Sand, Bernd Schmidt
Summary: The regioselectivity of two mechanistically distinct alkenylation reactions catalyzed by in situ-formed cationic transition metal complexes was studied using N-allyl-N-phenylethenesulfonamide as a model compound. Orthogonal selectivity was observed for the Ru-catalyzed C-H-activating alkenylation with acetanilides, which occurs preferentially at the electron deficient double bond, and for a Pd-catalyzed Heck-type coupling with arene diazonium salts, which occurs preferentially at the more electron rich double bond of the N-allyl substituent.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Ryota Sato, Tomoki Lida, Takaki Kanbara, Junpei Kuwabara
Summary: This Pd-catalysed cross-dehydrogenative coupling reaction allows the introduction of two polyfluoroarenes into simple polyaromatic hydrocarbons at sterically favourable positions. The investigation of the reaction mechanism revealed that the unique regioselectivity is determined by the reductive elimination step rather than the C-H bond cleavage step.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Jia-Xue Wu, Qing-Xia Yao, Wen-Zeng Duan, Da-Cheng Li, Xian-Qiang Huang, Jian-Min Dou, Huai-Wei Wang
Summary: This study revealed an efficient strategy for aryl-heteroaryl formation via Rh(III)-catalyzed ortho-C(sp(2))-H heteroarylation of (hetero)arenes using a readily removable N-2,6-difluorophenyl arylamide directing group. The protocol showed good tolerance towards various heteroaromatic boronates as coupling partners, offering a potential route for synthesizing heterocyclic drug molecules in medicinal chemistry.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Chong-Hui Xu, Liang Zeng, Gui-Fen Lv, Jing-Hao Qin, Xin-Hua Xu, Jin-Heng Li
Summary: A palladium(0)-catalyzed beta-C(sp(3))-H arylation reaction of silyl prop-1-en-1-ol ethers with aryl halides for the synthesis of alpha,beta-unsaturated ketones is described. The chemoselectivity of the reaction depends on the Pd(0) catalytic system and reaction temperature, resulting in either beta-C(sp(3))-H monoarylation or beta-C(sp(3))-H diarylation. The method uses readily available ketone-derivatized alpha-nonsubstituted silyl prop-1-en-1-ol ethers as alkene sources and demonstrates good functional group compatibility, broad substrate scope, and excellent selectivity.
Article
Chemistry, Organic
Kartic Manna, Ranjan Jana
Summary: We describe a mild and highly selective palladium-catalyzed cross-electrophile coupling between aromatic diazonium salts and aryl iodides or diaryliodonium salts in a water-ethanol (2:1) medium. Mechanistic studies revealed the importance of ethanol in generating an active Pd(0) catalyst, and the counterion of the diazonium salt promotes the formation of a cationic Pd(II) species that facilitates subsequent oxidative addition to aryl iodides/diaryliodonium salts. The presence of silver(I) salt is crucial for maintaining the catalytic activity of palladium by removing iodide ions as precipitates.
Article
Chemistry, Applied
Liang-Neng Wang, Pan-Ting Tang, Ming Li, Jia-Wei Li, Yue-Jin Liu, Ming-Hua Zeng
Summary: The combination of 1,3-diketone and amino acid ligands is essential for the ruthenium-catalyzed C(sp(2))-H arylation of dialkyl phosphines, providing a direct access to aryl-substituted dialkyl phosphine ligands. Mechanistic studies showed that the 1,3-diketone promoted the process of oxidative addition of a cycloruthenium intermediate, and some modified CyJohnPhos ligands exhibited highly catalytic activity in palladium catalyzed C-N bond formation.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Hao Dong, Yongxing Zhang, Xiaochen Tian, Ruochen Pang, Weiwu Ren, Yang Wang
Summary: This study developed a novel and efficient catalyst-free and oxidant-free synthesis method for highly substituted 5,6-dihydropyrazolo[5,1-a]isoquinolines. Different types of enamides and enamines, especially those derived from marketed drugs and bioactive molecules, are suitable substrates. The synthesis of a CB1 cannabinoid receptor antagonist using this methodology demonstrates its practicality for synthesizing valuable structural motifs.
Article
Chemistry, Multidisciplinary
Jun Wu, Nikolaos Kaplaneris, Julia Poehlmann, Takuya Michiyuki, Binbin Yuan, Lutz Ackermann
Summary: The prevalence of C-aryl glycosides in biologically active natural products and approved drugs has motivated the development of efficient synthesis strategies. Palladium catalysts with prefunctionalized substrates have been commonly used, while ruthenium-catalyzed C-aryl glycoside synthesis has been challenging. In this study, a versatile ruthenium(II)-catalyzed meta-C-H glycosylation method was disclosed, allowing for the synthesis of meta-C-aryl glycosides from readily available glycosyl halide donors. The ruthenium catalysis exhibited mild reaction conditions, exceptional levels of anomeric selectivity, and exclusive meta-site-selectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Takeshi Yatabe, Tamon Tome, Yukina Takahashi, Takahiro Matsumoto, Ki-Seok Yoon, Hidetaka Nakai, Seiji Ogo
Summary: This study presents the first example of C-H arylation of benzene under mild conditions using H-2 as an electron source {with turnover numbers (TONs) of 0.7-2.0 for 24 hours}. The reaction relies on a Rh-based electron storage catalyst, operates at room temperature and in aqueous solution, and effectively suppresses unwanted side reactions by rendering H-2 inactive during the radical transfer step.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
