Article
Chemistry, Applied
Mohammad Aslam, Shreedhar Devkota, Sana Jamshaid, Yong Rok Lee
Summary: A synthetic strategy for the installation of diversely functionalized quinones at the C4 position of indoles has been developed. This method provides a rapid and efficient route to a variety of 4-quinonylindoles and biologically interesting bis(indol-4-yl)quinones.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Physical
Lingheng Kong, Xi Han, Haohua Chen, Huaming Sun, Yu Lan, Xingwei Li
Summary: The regioselective coupling of NH indoles with diazo compounds using dimeric Rh(II) complexes as catalysts demonstrates selectivity towards C(6) or C(7) positions depending on the structure of the indoles. Mechanistic studies reveal that hydrogen-bonding directing effect plays a crucial role in determining the regioselectivity, with C-C bond formation proceeding through Friedel-Crafts-type attack. This work highlights the challenges and opportunities in controlling regioselectivity in reactions involving arene C-H bonds.
Article
Chemistry, Organic
Xi Chen, Zhe Zhang, Wei-Yu Shi, Ya-Nan Ding, Yu-Yong Luan, Yan-Chong Huang, Qiang Wang, Xue-Yuan Liu, Yong-Min Liang
Summary: We report a redox-neutral, visible-light-mediated difluoroalkylation of unactivated C(sp(3))-H bonds in amides via nitrogen-centered radicals triggered intramolecular hydrogen atom transfer. All types of gamma-C(sp(3))-H bonds exhibited excellent reactivity. This methodology provides a facile route for regioselective introduction of alpha,alpha-difluoroketonefragments into organic molecules, which can be easily converted to structurally diverse difluoro-containing molecules with broad potential applications in medicinal chemistry and chemical biology.
Article
Chemistry, Multidisciplinary
Rodney A. Fernandes, Priyanka Choudhary
Summary: This paper reports a sequential iodination of sulfonamides using inexpensive and milder molecular iodine as the iodinating reagent. The nickel and cobalt-catalyzed reaction results in ortho-iodinated arylsulfonamide products, with the 8-amino-5-iodoquinoline moiety serving as a directing group. This methodology can be extended to the synthesis of various value-added products through coupling reactions.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Organic
Peng-Chao Gao, Zi-Xuan Wang, Bi-Jie Li
Summary: The method involves iridium-catalyzed hydroalkynylation of allylic alcohols protected by an oxime group, generating gamma-alkynyl alcohol oximes directly. The oxime group can be easily removed to obtain free alcohols, offering an indirect route for the catalytic hydroalkynylation of allylic alcohols.
Article
Chemistry, Organic
Geetanjali S. Sontakke, Chiranjit Ghosh, Kuntal Pal, Chandra M. R. Volla
Summary: In this study, a substrate-controlled strategy was developed for the selective synthesis of C3 or C2-alkynylated indoles via ruthenium-catalyzed [3 + 2]-annulation. The key features of this strategy include operationally simple conditions, external-oxidant-free reaction, broad substrate scope, and substrate-switchable indole synthesis.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jia-Wen Yang, Guang-Qiang Tan, Kai-Cheng Liang, Ke-Dong Xu, Ma Su, Feng Liu
Summary: A copper-catalyzed reaction for synthesizing diverse alkene/alkyne-containing azepanes through selective functionalization of distal unactivated carbon atoms and broad substrate scope is reported. This reaction allows for late-stage modification of pharmaceuticals and natural products. A radical mechanism involving 1,5-hydrogen atom transfer of N-radicals, facile coupling of alkyl radicals with 1,3-dienes/1,3-enynes, and the construction of azepane motifs via C-N bond formation is proposed.
Article
Chemistry, Organic
Somratan Sau, Arghadip Ghosh, Majji Shankar, Manash Protim Gogoi, Akhila Kumar Sahoo
Summary: The study demonstrates a unprecedented thioamide-directed cobalt-catalyzed umpolung annulation reaction for the synthesis of highly substituted 2-amidoindenones. The transformation shows regioselectivity and constructs diverse structures, showcasing broad scope and success on a gram scale.
Article
Chemistry, Organic
Shuo-Jie Shen, Zhen Zhang, Yi Gu, Cheng-Hao Gu, Xu Yang, Hua-Jin Xu, Yi Hu
Summary: We have developed a cobalt catalyst that is stable in air and abundant in earth, for a regioselective mono-olefination of arenes directed by urea. This reaction operates under mild conditions, with a high selectivity and yield of up to 90%. Compared to noble-metal-catalyzed reactions, our method offers milder reaction conditions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Raziullah, Mohit Kumar, Afsar Ali Khan, Himangsu Sekhar Dutta, Ashfaq Ahmad, Jayanti Vaishnav, Ruchir Kant, Ravi Sankar Ampapathi, Dipankar Koley
Summary: A regioselective hydroarylative coupling of indolines with internal alkynes has been developed using a Ru(II)-catalyst, providing high yields and easy operation. The method can be applied to a variety of alkyne-containing compounds, showing great potential for broad applications.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Zhi-Jiang Jiang, Si-Han Xu, Yuhang Su, Erxun Hu, Jiawei Han, Jian-Fei Bai, Bencan Tang, Jia Chen, Zhanghua Gao
Summary: A nickel-catalyzed hydrogen isotope exchange has been developed using acetone-d6 as the deuterium source. With the assistance of 2-pyridones, the reaction exhibits improved kinetic features of H/D exchange, leading to the efficient synthesis of regioselective labeled aryl and alkyl carboxamides.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Hee Chan Noh, Cheol-Eui Kim, Kyungsup Lee, Dongwook Kim, Phil Ho Lee
Summary: A regioselective B(4)-alkenylation method has been developed using o-carboranyl sulfoxonium ylides and alkynes through B(4)-H activation catalyzed by Iridium(I). Sequential B(4)- and B(6)-alkenylation reactions resulted in the synthesis of B(3,5)-dialkenylated o-carboranyl sulfoxonium ylides in one pot. This method allows the introduction of two alkenyl groups at positions 3 and 5 of the carborane, with the sulfoxonium ylide serving as a directing group that can be further functionalized to B-alkenylated o-carboranyl trichloromethyl ketones.
Review
Biochemistry & Molecular Biology
Hongsheng Ma, Tongyan Yu, Longxiao Chi, Cong Huang, Xuwen Li, Rui Zhang, Chao Deng
Summary: Indole compounds are commonly found in natural products and drug candidates. The transition-metal-catalyzed regioselective C-H bond functionalization of indoles has been extensively studied in the past two decades. However, the general rules of regioselectivity are still unclear.
JOURNAL OF MOLECULAR MODELING
(2022)
Article
Chemistry, Multidisciplinary
Minoo Dabiri, Seyed Iman Alavioon
Summary: This work presents an efficient method for the regioselective alkenylation of 2-phenylphthalazinone through N-directing group via C-H activation process using Ru(II)-organometallic complex catalyst. Satisfactory results were obtained for a wide range of substrates bearing different electron-donating and electron-withdrawing groups.
Article
Chemistry, Applied
Fei Zhao, Jing Chen, Jin Qiao, Yangbin Lu, Xiaoning Zhang, Hui Mao, Shiyao Lu, Xin Gong, Siyu Liu, Xiaowei Wu, Long Dai
Summary: This study achieved the synthesis of functionalized 1H-imidazo[1,5-a]indol-3(2H)-ones by utilizing electron-deficient alkynes as unconventional C-1 synthons in a redox-neutral rhodium(III)-catalyzed [4+1] annulation. The process exhibited high chemo- and regioselectivity, broad substrate scope, good tolerance of functional groups, moderate to high yields, and mild redox-neutral conditions, providing a robust method to access valuable 1H-imidazo[1,5-a]indol-3(2H)-ones.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Balaji V. Rokade, Karthik Gadde, Kandikere Ramaiah Prabhu
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2015)
Article
Chemistry, Organic
Begur Vasanthkumar Varun, Karthik Gadde, Kandikere Ramaiah Prabhu
Article
Chemistry, Organic
Begur Vasanthkumar Varun, Karthik Gadde, Kandikere Ramaiah Prabhu
ORGANIC & BIOMOLECULAR CHEMISTRY
(2016)
Article
Chemistry, Organic
Devi Prasan Ojha, Karthik Gadde, Kandikere Ramaiah Prabhu
Article
Chemistry, Organic
Devi Prasan Ojha, Karthik Gadde, Kandikere Ramaiah Prabhu
JOURNAL OF ORGANIC CHEMISTRY
(2017)
Article
Chemistry, Applied
Balaji V. Rokade, Karthik Gadde, Kandikere Ramaiah Prabhu
ADVANCED SYNTHESIS & CATALYSIS
(2014)
Article
Chemistry, Multidisciplinary
Wim E. Van Beek, Karthik Gadde, Kourosch Abbaspour Tehrani
CHEMISTRY-A EUROPEAN JOURNAL
(2018)
Article
Chemistry, Physical
Karthik Gadde, Pieter Mampuys, Andrea Guidetti, H. Y. Vincent Ching, Wouter A. Herrebout, Sabine Van Doorslaer, Kourosch Abbaspour Tehrani, Bert U. W. Maes
Review
Chemistry, Organic
Dries De Vos, Karthik Gadde, Bert U. W. Maes
Summary: This paper provides an overview of the development and application of visible light photocatalysis, and introduces some lesser-known modes of photochemical activation of organic molecules and emerging techniques in this field.
SYNTHESIS-STUTTGART
(2023)
Review
Chemistry, Organic
Karthik Gadde, Dries De Vos, Bert U. W. Maes
Summary: Visible light photocatalysis is a promising and sustainable strategy to access reactive intermediates and catalyze organic transformations under mild conditions. This tutorial review provides an overview of the essential concepts and techniques of visible-light-mediated chemical processes and discusses the most common types of photochemical activation of organic molecules. Examples of photocatalytic alkene functionalization reactions are presented to illustrate the basic concepts and techniques, with a focus on understanding their reaction mechanisms.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Karthik Gadde, Bert U. W. Maes, Kourosch Abbaspour Tehrani
Summary: An efficient metal-free strategy has been developed for the synthesis of alpha-substituted homoallylamine derivatives via a 2-aza-Cope rearrangement promoted by HFIP. This method provides rapid access to the desired products with excellent functional group tolerance and high yields, without the need for chromatographic purification. The synthetic utility of this method is further demonstrated through the transformation of benzophenone ketimines into various compounds.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Karthik Gadde, Jonas Daelemans, Bert U. W. Maes, Kourosch Abbaspour Tehrani