Article
Chemistry, Physical
Jayabrata Das, Dibya Kanti Mal, Suman Maji, Debabrata Maiti
Summary: Selective functionalization of C-H bonds is a crucial topic in organic synthesis, utilizing the abundant portion of a molecule for synthetic manipulations. Utilizing native carboxylate groups for C-H activation can eliminate the need for exogenous directing groups, increasing reaction diversity. The coverage of carboxylate-aided functionalizations of organic molecules without decarboxylation is expected to be unique and beneficial for researchers in academia and industry.
Article
Chemistry, Organic
Ge Zhang, Meng-Yao Li, Wen-Bo Ye, Zhi-Tao He, Chen-Guo Feng, Guo-Qiang Lin
Summary: A new palladium-catalyzed alkyl C-H borylation with bromide as a traceless directing group has been described, allowing for the convenient access to alkyl boronates bearing a beta-allcarbon quaternary stereocenter. The protocol demonstrates broad substrate scope, excellent site selectivity, and good functional group tolerance.
Article
Chemistry, Organic
Sunit Hazra, Koji Hirano, Masahiro Miura
Summary: A novel method for C4-selective C-H alkenylation of 3-carboxy-2-pyridones with styrenes has been developed using a rhodium catalyst. The carboxylic group at the C3 position plays a key role in directing the C4 alkenylation of the products with concomitant decarboxylation. The exclusive C4 selectivity is observed even in the presence of potentially more reactive C-H bonds, allowing for the preparation of multiply substituted 2-pyridones via sequential C-H functionalization reactions.
Article
Chemistry, Organic
Bao Chao, Chaolumen Bai, He Yan, Ruisheng Zhao, Dan Liu, Tegshi Muschin, Agula Bao, Chaolu Eerdun, Yong-Sheng Bao
Summary: Herein, we present a common approach for direct coupling of the ortho-C-H bond of aromatic aldehydes with various organoboronic reagents using a transient directing strategy. Unlike the widely used cross-coupling reactions, this method utilizes BQ/TFA as a weak oxidation system, making it cost-effective, environmentally friendly, and aligned with green catalysis. This broad and efficient method provides a new route for the direct formation of carbon-carbon bonds through C-H bond activation.
Article
Chemistry, Applied
Jitan Zhang, Jian Fan, Ziyi Guo, Yehe Wu, Jiaping Wu, Meihua Xie
Summary: A concise method for the synthesis of axially chiral biaryl aldehydes has been developed through Pd/amino acid-catalyzed interannular C-H arylation of biaryl aldehydes with aryl iodides. This reaction exhibits excellent enantioselectivity and good tolerance towards functional groups. The scalability and potential utility of this asymmetric catalytic protocol have been highlighted.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Mixiang Tian, Lidong Shao, Xiaosan Su, Xuhong Zhou, Honglei Zhang, Kun Wei, Ruifen Sun, Junliang Wang
Summary: A new method has been developed for selective oxygenation of benzaldehydes and benzylic amines at the ortho positions to prepare fluoroalkyl aryl ethers.
Article
Chemistry, Multidisciplinary
Md. Emdadul Hoque, Jin-Quan Yu
Summary: In this study, we report a new method for the gamma-arylation and gamma-lactonization of aliphatic acids, enabled by a L,X-type CarboxPyridone ligand catalyzed Pd(II) reaction. A wide range of gamma-arylated gamma-lactones can be efficiently synthesized in a single step, and the arylated lactones can be further converted into disubstituted tetrahydrofurans, which are prominent scaffolds in bioactive molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Lincong Sun, Yuyao Zhao, Bingxian Liu, Junbiao Chang, Xingwei Li
Summary: The rhodium-catalyzed tandem twofold C-H bond activation reactions of para-olefin-tethered arenes have been achieved, leading to the synthesis of diverse 2,3-dihydrobenzofuran platforms. The reaction proceeds through the activation of ortho-C-H bonds in the arene and sequential activation of meta-C-H bonds, resulting in C-C or N-C difunctionalization.
Article
Chemistry, Multidisciplinary
Mingyu Liu, Juntao Sun, Tugce G. Erbay, Hui-Qi Ni, Raul Martin-Montero, Peng Liu, Keary M. Engle
Summary: This paper describes a palladium(II)-catalyzed C(alkenyl)-H alkenylation reaction enabled by a transient directing group strategy. The reaction takes advantage of reversible condensation between the substrate and a transient directing group to facilitate the coordination of the metal catalyst and subsequent activation of the C(alkenyl)-H bond. The reaction produces 1,3-dienes with high regio- and E/Z-selectivity and enables the synthesis of enantioenriched atropoisomeric 2-aryl-substituted 1,3-dienes that have seldom been studied before. The reaction mechanism and stereoinduction model were elucidated by density functional theory calculations and the alkenyl palladacycles were characterized by X-ray crystallography.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Organic
Fu Zhengjiang, Cao Xihan, Yin Jian, Gou Zhenyu, Yi Xuezheng, Cai Hu
Summary: By using carboxylic acid as a directing group, the controllable functionalization of ortho-C-H bond can be achieved, avoiding the extra steps of introducing and removing the directing group and highlighting the green chemistry advantages.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Ashutosh Verma, Anil J. Elias
Summary: In this study, a palladium-catalyzed 'on-water' methodology for the synthesis of biaryl and m-teraryl derivatives of aryl carboxamides by selective mono and bis C-H bond functionalization is reported. The reaction was carried out using 8-aminoquinoline and 2-thiomethylaniline as directing groups and water as the solvent, resulting in high yields of the functionalized products. The insoluble nature of the products in water allowed for the reusability of the solvent and catalyst.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Review
Chemistry, Multidisciplinary
Yingtao Wu, Chao Pi, Yangjie Wu, Xiuling Cui
Summary: Directing group migration has emerged as a practical strategy for transition-metal-catalysed direct C-H activation, leading to highly atom-economical processes and enabling the reusage of directing groups. Progress has been made in developing multitasking directing groups, with the focus on different types of migratable directing groups and their mechanisms, as well as synthetic applications.
CHEMICAL SOCIETY REVIEWS
(2021)
Article
Chemistry, Multidisciplinary
Guangrong Meng, Liang Hu, Martin Tomanik, Jin-Quan Yu
Summary: Pd-II-catalyzed beta- and gamma-C(sp(3))-H heteroarylation of free carboxylic acids using pyridine-pyridone ligands overcomes limitations in selective functionalization and compatibility with heteroatoms. A sequence of three consecutive C(sp(3))-H activation reactions of pivalic acid constructs diverse quaternary carbon centers containing heteroaryls, offering a valuable tool for breaking new ground in medicinal chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Zhe Zhuang, Shuang Liu, Jin-Tang Cheng, Kap-Sun Yeung, Jennifer X. Qiao, Nicholas A. Meanwell, Jin-Quan Yu
Summary: In this study, a novel C-H functionalization reaction was reported, which utilizes common protecting groups and practical oxidants for the lactamization of tosyl-protected aliphatic amides. The reaction was enabled by a specific ligand and shows mild reaction conditions, good scalability, and the use of convenient oxidants and protecting groups. Further derivatization of the beta-lactam products allows the synthesis of various biologically significant compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Zhe Zhuang, Alastair N. Herron, Jin-Quan Yu
Summary: The development of C(sp(3))-H functionalizations of free carboxylic acids has provided a wide range of versatile reactions, enabling convenient synthesis of cyclic anhydrides using Mo(CO)(6) as a solid CO source and a bidentate ligand. Succinic anhydride products serve as versatile intermediates for introducing various functional groups at the beta position of parent acids, offering a divergent strategy for synthesizing carboxylic acids inaccessible by previous beta-C-H activation reactions. Furthermore, enantioselective carbonylation of free cyclopropanecarboxylic acids has been achieved using a chiral bidentate thioether ligand.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Pradip Ramdas Thorve, Biplab Maji
Summary: A new method was developed in this study using bioinspired o-quinone cofactor catalyzed aerobic primary amine dehydrogenation, leading to the cascade olefination reaction of nine different methyl N-heteroarenes and providing high yields and (E)-selectivities in synthesizing N-heteroaryl stilbenoids without the need for transition-metal salt, ligand, stoichiometric base, or oxidant under mild conditions.
Article
Chemistry, Organic
Sayan K. Jana, Mamata Maiti, Purusattam Dey, Biplab Maji
Summary: A facile synthesis method for mono-, 1,1-and 1,2-disubstituted cyclopropanes via visible light-mediated photoredox/nickel dual catalysis under mild conditions was demonstrated. Mechanistic inspection and control experiments revealed the importance of dual catalysis and the reaction proceeds via a stepwise oxidative addition followed by an intramolecular S(N)2 reaction.
Article
Chemistry, Multidisciplinary
Ayan Jati, Kaushik Dey, Maryam Nurhuda, Matthew A. Addicoat, Rahul Banerjee, Biplab Maji
Summary: This study presents a dual metalation strategy using a COF TpBpy for C-N cross-coupling reactions. The strategy demonstrates controlled metalation, recyclability, and visible-light-mediated catalysis. Experimental and theoretical studies provide insights into the catalyst and reaction mechanism.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Satyadeep Waiba, Mamata Maiti, Biplab Maji
Summary: In this study, a sustainable catalytic pathway was developed to convert readily available feedstocks into valuable α-hydroxycarboxylic acid molecules. A bench stable metal complex was used as the catalyst, enabling the selective transformation of vicinal glycols into α-hydroxycarboxylic acids at low temperature. The protocol showed high efficiency and applicability for various types of vicinal glycols, with significant potential in the synthesis of bioactive molecules and biodegradable polymers.
Article
Chemistry, Organic
Purusattam Dey, Sayan K. Jana, Pramod Rai, Biplab Maji
Summary: This study reports a method for the direct 1,2-dicarbofunctionalization of unactivated olefins, achieved under photoredox/nickel dual catalysis. The mildness of the visible-light-mediated reaction allows for the use of various alkyl and aryl electrophiles, including those with sensitive functional groups. The protocol is suitable for late-stage diversification of drugs and biologically active molecules. Investigations elucidated the importance of photoredox/nickel dual catalysis and α-amino-radical-mediated halogen atom transfer, and provided nickel complexes involved in the reaction.
Article
Chemistry, Multidisciplinary
Satyadeep Waiba, Kakoli Maji, Mamata Maiti, Biplab Maji
Summary: In this study, we present a simple synthesis method for valuable alpha-hydroxycarboxylic acid molecules through an acceptorless dehydrogenative coupling of ethylene glycol and primary alcohols. A stable manganese complex catalyst facilitated the reaction, which showed scalability and high yields with excellent selectivities under mild conditions. The protocol is environmentally friendly, generating only water and hydrogen gas as byproducts. Furthermore, it was successfully applied to synthesize various drugs and bioactive molecules, demonstrating its broad applicability and potential in organic synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Akash Jana, Sayandip Chakraborty, Koushik Sarkar, Biplab Maji
Summary: In this study, we report the ruthenium-catalyzed synthesis of fi-alkylated secondary alcohols through the regioselective ring opening of epoxides with primary alcohols. The reaction employs alcohol as the carbon source and terminal reductant, and operates through tandem Markovnikov selective transfer hydrogenation of terminal epoxides and hydrogen transfer-mediated cross-coupling of the resulting alcohol with primary alcohol substrates. A broad scope of substrates, including drug and natural product derivatives, is demonstrated with excellent regioselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Sovan Dey, Arindam Das, Ram Naresh Yadav, Palash Jyoti Boruah, Prerana Bakli, Tania Baishya, Koushik Sarkar, Anup Barman, Ranabir Sahu, Biplab Maji, Amit Kumar Paul, Md. Firoj Hossain
Summary: A mild and eco-friendly visible-light-induced synthesis of 2-(2-hydrazinyl) thiazole from readily accessible starting materials is reported. The reaction proceeds without the need for a metal catalyst or extrinsic photosensitizer, and only requires visible light and a green solvent. The synthesized compounds showed significant antioxidant and antidiabetic properties in vitro.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Pradip Ramdas Thorve, Kakoli Maji, Biplab Maji
Summary: In this study, a practical and regioselective synthesis of 1,2,4-triazoles utilizing amine oxidase-inspired catalysis was reported. The method is atom-economical and environmentally benign, resulting in molecules with varying structural diversity.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Akash Jana, Sayandip Chakraborty, Koushik Sarkar, Biplab Maji
Summary: Here, we demonstrate a ruthenium-catalyzed method for synthesizing fi-alkylated secondary alcohols through the selective ring opening of epoxides with primary alcohols. The reaction uses alcohol as both the carbon source and the terminal reductant. Kinetic and labeling experiments reveal that the reaction proceeds through tandem Markovnikov selective transfer hydrogenation of terminal epoxides and hydrogen transfer-mediated cross-coupling of the resulting alcohol with primary alcohol substrates. The reaction shows a broad scope, including 40 examples of drugs/natural product derivatives, and exhibits excellent regioselectivity for various substrates.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Pramod Rai, Kakoli Maji, Sayan K. Jana, Biplab Maji
Summary: The article describes a visible-light energy-transfer catalysis method for the intermolecular dearomative [4 + 2] cycloaddition reaction of naphthalene molecules with vinyl benzenes. The method has good functional group tolerance and high yields, and can be used for late-stage modification of pharmaceutical derivatives. The effectiveness of the method is further demonstrated through post-synthetic diversification.
Article
Chemistry, Multidisciplinary
Kakoli Maji, Pradip Ramdas Thorve, Pramod Rai, Biplab Maji
Summary: An enantioselective ortho-C(sp(2))-H functionalization of ketones with 1,6-enynes is demonstrated using photoredox/cobalt dual catalysis. This method shows high yields, tolerance towards functional groups, and selectivity. Mechanistic studies reveal that the key steps involve visible-light mediated generation of low-valent cobalt complex, intramolecular cyclization, ortho-C-H bond insertion, and reductive elimination.
CHEMICAL COMMUNICATIONS
(2022)
Review
Chemistry, Multidisciplinary
Kuhali Das, Satyadeep Waiba, Akash Jana, Biplab Maji
Summary: The emerging field of organometallic catalysis has shifted towards research on Earth-abundant transition metals. Manganese has emerged as one of the leading competitors, playing an important role in hydrogenation, dehydrogenation, and hydroelementation reactions. Catalyst design is based on metal-ligand bifunctionality, ligand hemilability, and redox activity, resulting in different turnover numbers for product molecules.
CHEMICAL SOCIETY REVIEWS
(2022)
Review
Chemistry, Multidisciplinary
Purusattam Dey, Pramod Rai, Biplab Maji
Summary: Asymmetric catalysis utilizing chiral-at-metal complexes has emerged as an attractive strategy in recent developments, where the catalysts coordinatively activate a substrate while providing the chirality. These configurationally stable complexes have been applied in asymmetric transformations ranging from Lewis acid catalysis to photoredox and electrocatalysis. This comprehensive review focuses on the advancements in asymmetric catalysis using iridium and rhodium-based chiral-at-metal complexes as catalysts, which involve LUMO and HOMO activation, visible-light-induced asymmetric catalysis, and electricity-driven asymmetric transformations.
ACS ORGANIC & INORGANIC AU
(2022)
