Review
Chemistry, Organic
Pinaki Nad, Arup Mukherjee
Summary: Acceptorless dehydrogenative coupling reactions using manganese catalyst is a promising and sustainable method for constructing carbon-carbon and carbon-heteroatom bonds. The methodology is highly atom economical, producing water and hydrogen as byproducts, and provides a unique opportunity for constructing various synthons and biologically important motifs. Recent progress in this field has been made with manganese catalysis based on pincer ligands for various homogeneous transformations.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Zhenwei Ni, Rosa Padilla, Rajib Pramanick, Mike S. B. Jorgensen, Martin Nielsen
Summary: A base-free, acceptorless dehydrogenative coupling of ethanol to ethyl acetate is achieved using a pincer complex ((PNP)-P-Ph)RuH(BH4)(CO) (0.25 mol%) and m-xylene as the co-solvent. The catalysis shows excellent conversion and yield of >99% after 24 h at 120 degrees C. The scaled-up reaction is also effective under similar conditions.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Physical
Gunasekaran Balamurugan, Rengan Ramesh
Summary: A new nickel complex catalyst is used for the synthesis of (E)-olefins via greener acceptorless dehydrogenative coupling methodology. This simple and efficient protocol is applicable to a wide range of substrates, including drug intermediates.
Article
Chemistry, Physical
Dipanjan Bhattacharyya, Priyanka Adhikari, Kritartha Deori, Animesh Das
Summary: The synthesis of N-heterocycles is important in pharmaceuticals, materials science, and natural product synthesis. This study presents an efficient method for the synthesis of quinoline and quinazoline derivatives through an alcohol-catalyzed acceptorless dehydrogenative coupling (ADC). The use of a bifunctional ruthenium NNN-pincer complex as the catalyst allows the synthesis of a wide range of substituted quinolines and quinazolines with high yields and selectivity.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Wenjun Yang, Ivan Yu Chernyshov, Robin K. A. van Schendel, Manuela Weber, Christian Muller, Georgy A. Filonenko, Evgeny A. Pidko
Summary: In this study, a highly efficient manganese pincer pre-catalyst was reported, displaying high TOF values (up to 41,000 h(-1)) and stability (TON up to 200,000) at loadings as low as 5-200 ppm. The crucial role of catalyst activation step for the catalytic performance and stability of the system was highlighted, with activation using hydride donor promoters significantly improving catalytic performance and eliminating induction times. Manganese-based hydrogenation catalysts are shown to be sensitive to high temperatures, but this pre-catalyst offers a promising alternative.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Yanling Zheng, Yang Long, Huihua Gong, Jiaqi Xu, Chunchun Zhang, Haiyan Fu, Xueli Zheng, Hua Chen, Ruixiang Li
Summary: In this study, the divergent transformations of 1,3-diols with arylhydrazines were reported, which selectively synthesized pyrazoles and 2-pyrazolines via acceptorless dehydrogenative coupling reactions using Ru3(CO)12/NHC-phosphinephosphine catalytic systems. The reactions showed low catalyst loading, high selectivity, wide substrate scope, and good yields, with only water and hydrogen gas (H2) as the byproducts.
Article
Chemistry, Applied
Vinita Yadav, Ekambaram Balaraman, Santosh B. Mhaske
Summary: This study reports an air-stable, molecularly defined NNN-Mn(II) pincer complex catalyzing acceptorless dehydrogenative coupling of alcohols with indoles, successfully synthesizing various bis(indolyl)methane derivatives and important structurally relevant products. Mechanistic studies highlight the significance of the NH moiety in the complex and the crucial role of metal-ligand cooperation during catalysis.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Inorganic & Nuclear
Rahul Kumar Singh, Dibya Yadav, Shilpi Misra, Amrendra K. Singh
Summary: An unexpected reversal in catalytic activity for acceptorless dehydrogenative coupling has been observed, where complexes with PPh3 and DMSO ligands performed better than complexes with CO and COD ligands. A plausible mechanism has been suggested to explain this difference and reversal.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Yaoyu Liang, Jie Luo, David Milstein
Summary: In this study, a new reaction of acceptorless dehydrogenative coupling of epoxides and amines to form amides catalyzed by ruthenium pincer complexes is reported. This reaction shows high yield and selectivity, and is significant in various academic and industrial fields.
Article
Chemistry, Organic
Nandita Biswas, Dipankar Srimani
Summary: The Ru-catalyzed reaction provides an economical and simple operational strategy for synthesizing biologically active 1,8-dioxodecahydroacridine derivatives with a wide substrate scope and good tolerance toward various functional groups.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Ling Zhao, Xiaochun He, Tianhua Cui, Xufeng Nie, Jiaqi Xu, Xueli Zheng, Weidong Jiang, Maolin Yuan, Hua Chen, Haiyan Fu, Ruixiang Li
Summary: The acceptorless dehydrogenative cross-coupling of primary alcohols to form cross-esters with the liberation of H2 gas was achieved using a [RuCl(eta 6-C6H6)(Kappa 2-CNP)][PF6]Cl complex as the catalyst. This sustainable protocol is applicable to a wide range of primary alcohols, particularly those that are sterically demanding, and it exhibits good functional group tolerance and high selectivity. The nitrogen-phosphine-functionalized N-heterocyclic carbene (CNP) ligand, which adopts a facial coordination mode and allows for facile dissociation of coordinated benzene, is responsible for the excellent catalytic performance.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Pennamuthiriyan Anandaraj, Rengan Ramesh, Jan Grzegorz Malecki
Summary: A sustainable synthetic method for substituted benzimidazoles was reported via acceptorless de-hydrogenative coupling of primary alcohols using palladium catalysts. New non-classical Pd(II) N boolean AND N boolean AND S pincer complexes (1-3) were synthesized and characterized. The complexes exhibited distorted square planar geometry, confirmed by single-crystal X-ray diffraction study. The reaction showed high efficiency with 94% isolated yield and only 1% catalyst loading, generating aldehyde intermediate, hydrogen, and water as the only byproducts.
JOURNAL OF ORGANOMETALLIC CHEMISTRY
(2023)
Article
Chemistry, Applied
Saranya Sundar, Ramesh Rengan, Anandaraj Pennamuthiriyan, David Semeril
Summary: A facile catalytic one-pot synthesis of N-acylhydrazones has been described using arene ruthenium (II) complexes. The method provides a wide range of N-acylhydrazones in good yields with high selectivity and functional group tolerance, without any alkylated products.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Michael Montag, David Milstein
Summary: The amide functional group is widely distributed in living organisms and is particularly important in bioactive compounds and pharmaceuticals. However, the current method for amide synthesis relies heavily on traditional condensation reactions, which pose sustainability challenges. Therefore, developing sustainable approaches to amide synthesis is essential. Over the past two decades, homogeneous catalytic reactions, particularly ruthenium-catalyzed acceptorless dehydrogenative coupling, have been developed to achieve amide synthesis without coupling reagents and waste generation, with H-2 gas being the only byproduct.
PURE AND APPLIED CHEMISTRY
(2023)
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, Inorganic & Nuclear
Prosenjit Daw, Amit Kumar, Dror Oren, Noel Angel Espinosa-Jalapa, Dipankar Srimani, Yael Diskin-Posner, Gregory Leitus, Linda J. W. Shimon, Raanan Carmieli, Yehoshoa Ben-David, David Milstein
Article
Chemistry, Inorganic & Nuclear
Pragati Pandey, Prosenjit Daw, Noor U. Din Reshi, Kira R. Ehmann, Markus Hoelscher, Walter Leitner, Jitendra K. Bera
Review
Chemistry, Physical
Amit Kumar, Chang Gao
Summary: The increasing production and usage of consumer products and energy sources have led to the accumulation of toxic waste products, posing a severe threat to the planet. The concept of circular chemistry proposes the utilization of waste products as feedstocks for useful chemicals, with catalytic (de)hydrogenation being a green and sustainable approach. Studies on homogeneous catalytic (de)hydrogenation have shown potential to convert chemical wastes into valuable resources, with examples including CO2, N2O, plastics, and glycerol as waste materials for transformation.
Article
Chemistry, Organic
Amit Kumar, James Luk
Summary: The study introduces a method for catalytic hydrogenation of various urea derivatives to produce amines and methanol with high yields using ruthenium or iridium Macho pincer complex catalysts. Additionally, the concept is expanded to demonstrate the first example of hydrogenative depolymerization of polyureas to produce diamines and methanol with moderate yields.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Jagannath Rana, Satabdee Tanaya Sahoo, Prosenjit Daw
Summary: Recent advances in homogeneous first-row transition-metal catalyzed for hydrogen production and important organic transformations focus on earth-abundant 3d base-metal complexes, showing promise for sustainable catalysis development.
Review
Chemistry, Multidisciplinary
Amit Kumar, Prosenjit Daw, David Milstein
Summary: This article reviews recent developments of homogeneous catalysts in emerging applications of sustainable energy, with a focus on hydrogen storage, the methanol economy, and the production of conventional fuels from biomass or lower alkanes. Additionally, the production of ethylene glycol from CO and H-2 is discussed, with particular emphasis on well-defined transition metal complexes, such as pincer complexes, due to their high activity and well-studied mechanisms.
Article
Chemistry, Physical
Aniekan Ekpenyong Owen, Annika Preiss, Angus McLuskie, Chang Gao, Gavin Peters, Michael Buehl, Amit Kumar
Summary: Urea derivatives and polyureas are important compounds with diverse applications. However, the conventional synthesis methods involving toxic reagents pose risks to the environment and human health. In this study, a catalytic reaction using safer reagents was developed to synthesize urea derivatives and polyureas. The method demonstrated high efficiency and atom economy, achieving moderate to quantitative yields of various compounds. Mechanistic insights were also provided through experiments and computational analysis.
Article
Chemistry, Multidisciplinary
Claire N. Brodie, Aniekan E. Owen, Julian S. Kolb, Michael Buhl, Amit Kumar
Summary: Polyethyleneimines have various applications in products like detergents, adhesives, cosmetics, and processes such as tissue culture, gene therapy, and CO2 capture. The current production method for branched polyethyleneimines uses a highly toxic, volatile, and mutagenic feedstock called aziridine, which raises significant health and environmental concerns. This study presents a novel approach to synthesize branched polyethyleneimine derivatives using safer, environmentally friendly, commercially available, and potentially renewable feedstocks such as ethylene glycol and ethylenediamine. The reaction is catalyzed by an abundant metal, manganese, and produces water as the only by-product.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Satabdee Tanaya Sahoo, Aisa Mohanty, Raju Sharma, Smruti Rekha Rout, Rambabu Dandela, Prosenjit Daw
Summary: In the present global situation, the transition to a more sustainable hydrogen economy is receiving great attention. This study used a bifunctional NNN-Ru system with protic arms and ligand cooperativity pathway and hydrogen-bonding interaction for hydrogen production from biomass-derived sorbitol. It achieved a maximum turnover number of 35359 during sorbitol reforming. The catalyst remained active for up to seven runs and showed efficient catalytic activity. NMR studies revealed the participation of functionalized ligands during catalysis.
Correction
Chemistry, Physical
Aniekan Ekpenyong Owen, Annika Preiss, Angus McLuskie, Chang Gao, Gavin Peters, Michael Buhl, Amit Kumar
Article
Chemistry, Inorganic & Nuclear
Satabdee Tanaya Sahoo, Aisa Mohanty, Raju Sharma, Prosenjit Daw
Summary: The developed bifunctional NNN-Ru complex exhibits high catalytic efficiency for the selective production of hydrogen and glycolic acid from ethylene glycol. The optimized reaction conditions allow for further dehydrogenation of the organic substrate, resulting in higher hydrogen production. Mechanistic investigations were conducted to understand the role of the bifunctional catalyst.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Physical
Angus McLuskie, Claire N. Brodie, Michele Tricarico, Chang Gao, Gavin Peters, Aaron B. Naden, C. Logan Mackay, Jin-Chong Tan, Amit Kumar
Summary: This study reports the synthesis of polyureas through the dehydrogenative coupling of diamines and diformamides. The reaction is catalysed by a manganese pincer complex and produces H-2 gas as the only by-product, making the process atom-economic and sustainable. Compared to the current production routes using diisocyanate and phosgene feedstock, this method is greener. The physical, morphological, and mechanical properties of the synthesized polyureas are also investigated. Based on mechanistic studies, the reaction is proposed to proceed via isocyanate intermediates formed by the manganese-catalysed dehydrogenation of formamides.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Amit Kumar, Daniel Armstrong, Gavin Peters, Manjula Nagala, Sally Shirran
Summary: This study presents a novel method for the direct synthesis of polyureas from diamines and methanol using a ruthenium pincer catalyst. By replacing toxic diisocyanates with renewable and less toxic methanol, the overall process becomes safer and more sustainable. Additionally, the method has been shown to be versatile by synthesizing renewable, chiral, and C-13-labeled polyureas.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Inorganic & Nuclear
Akshi Tyagi, Noor U. Din Reshi, Prosenjit Daw, Jitendra K. Bera
DALTON TRANSACTIONS
(2020)
