Article
Chemistry, Applied
Matthias Elfinger, Christof Bauer, Joerg Schmauch, Michael Moritz, Christoph Wichmann, Christian Papp, Rhett Kempe
Summary: This study presents an efficient method for the selective synthesis of differently substituted primary, secondary, and tertiary alkyl amines by combining borrowing hydrogen or hydrogen autotransfer and reductive amination with hydrogen. A nanostructured, bimetallic Co/Sc catalyst is used to mediate both reactions efficiently. The method shows broad product scope, good functional group tolerance, easy upscaling, and catalyst reusability.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Inorganic & Nuclear
Keshav Paudel, Shi Xu, Oleksandr Hietsoi, Bedraj Pandey, Chuka Onuh, Keying Ding
Summary: The presence of base plays a crucial role in determining the selectivity of the imine and amine synthesis process. A catalytic amount of base leads to imine formation, while an excess loading of base results in amine product. The product selectivity also strongly depends on the organometallic catalysts used.
Article
Chemistry, Physical
Weikang Li, Ming Huang, Jiahao Liu, Yong-Liang Huang, Xiao-Bing Lan, Zongren Ye, Cunyuan Zhao, Yan Liu, Zhuofeng Ke
Summary: This study demonstrates the effective N-alkylation of anilines or challenging nitroarenes with alcohols through homogeneous Mo-catalysis, utilizing a strong hydride-donating ability of the easily accessible bis-NHC-Mo(0) complex. The enhanced hydride-donating strategy is valuable for designing highly active systems for borrowing hydrogen transformations.
Article
Chemistry, Multidisciplinary
Tsun-Ren Chen, Yu-Tung Chen, Yi-Sheng Chen, Wen-Jen Lee, Yen-Hsing Lin, Hao-Chen Wang
Summary: A facile way to synthesize C-N bonds using iridium/graphene catalyst is reported. The catalyst promotes the bond formation without pre-activation steps and does not require solvents, alkalis, or other additives. This methodology enables direct N-alkylation of amines with primary and secondary alcohols, resulting in good selectivity and excellent yields. The use of diols leads to intermolecular cyclization of amines, which is valuable for the synthesis of biologically active compounds. Two examples of hydroxyzine and cyclizine synthesis highlight the advantages of this catalyst in organic synthesis. The catalytic process produces only water as a by-product, making it sustainable and environmentally friendly.
Article
Chemistry, Applied
Hoang H. Pham, Bruno Donnadieu, T. Keith Hollis
Summary: "This study reports the first CCC-NHC pincer complex of Re, which is fully characterized by analytical techniques including NMR spectroscopy, mass spectroscopy, elemental analysis, and X-ray crystallography. The complex exhibits good air stability and catalytic activity for the borrowing hydrogen coupling reaction between benzylic ketones and primary alcohols, generating a new C-C bond without the need for alcohol functionality activation. The reaction produces water as the sole by-product and achieves high isolated yields ranging from 53% to 92% for a broad range of substrates."
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Priyanka Chakraborty, Basker Sundararaju, Eric Manoury, Rinaldo Poli
Summary: A combined computational and experimental investigation of three different Cp*CoIII systems used in combination with a base as catalysts in borrowing hydrogen alkylations by secondary alcohols reveal the existence of a new pathway for alcohol activation, differing from the existing paradigms of oxidative and ionic activations.
Article
Chemistry, Inorganic & Nuclear
Ruirui Yun, Wei Zhang, Zan Zhang, Xiaoxuan Zhang, Zhaoxu Wang, Shizhong Luo
Summary: In this study, a series of core-shell catalysts Cu@NC/PC were designed and synthesized for the first time using a functional polymer assistant strategy. Cu@NC/PC-900-2 exhibited excellent catalytic performance in the hydrogenation of nitroarenes, attributed to its large BET surface area and uniformly dispersed metal sites. The honeycomb-like structure facilitated mass transfer and active site exposure. Both experimental and theoretical results indicated that the N-doping sites promoted the adsorption of nitro groups, resulting in high activity and selectivity under low H-2 pressure and temperature. Importantly, the catalyst also achieved high conversion in gram-scale catalytic processes, highlighting its practical application potential.
INORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Physical
Merve Altinsoy, Ayhan Abdullah Ceyhan
Summary: In this study, a cobalt-doped catalyst was prepared from chicken eggshell powder for the hydrolysis of sodium borohydride. The effects of various parameters on the hydrolysis process were examined. The prepared catalyst showed a high hydrogen generation rate and good reusability, making it advantageous for use in sodium borohydride hydrolysis.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Organic
Jiajun Wu, Christophe Darcel
Summary: A novel method for the selective reduction of nitroarenes with various alcohols using an iron catalyst via hydrogen transfer has been efficiently developed. This methodology leads to imines with good functional group tolerance in yields ranging from 30-91%, and also provides a sustainable alternative for the preparation of quinoxalines and benzimidazoles.
JOURNAL OF ORGANIC CHEMISTRY
(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, Physical
Wasim Ullah Khan, Ahmed Al Shoaibi, Srinivasakannan Chandrasekar, Mohammad M. Hossain
Summary: Nickel and cobalt-based titania-supported bimetallic catalysts with varying metal loading were synthesized. High-loading catalysts showed higher activity and stability, with 25NCT catalyst exhibiting the highest methane conversion and carbon yield. The catalyst's enhanced activity can be attributed to its higher specific surface area and the formation of carbon nanotubes through tip-growth and base-growth mechanisms.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Organic
Maria H. T. Kwan, Nisha P. B. Pokar, Catherine Good, Martin F. Jones, Rachel Munday, Thomas Screen, A. John Blacker
Summary: Research has shown that catalyst deactivation occurs when ammonia or methylamine are liberated by hydrolysis or aminolysis of the intermediate imine, tightly coordinating with the iridium center to block turnover. Control of moisture and substrate concentration can suppress deactivation, and partial reactivation of spent catalyst was identified using hydroiodic acid.
Article
Chemistry, Multidisciplinary
Xiaochun Liu, Chaoyue Wang, Jiaolong Meng, Xiaodong Yue, Qingyun Wang, Jiatian Lu, Junke Wang, Xicun Wang, Yingxiao Zong, Xuefeng Jiang
Summary: This study successfully synthesized a mesoporous catalyst with single-atomic cobalt active sites, and demonstrated its excellent performance and potential applications in the hydrogenation of nitroarenes.
CHINESE CHEMICAL LETTERS
(2023)
Article
Chemistry, Inorganic & Nuclear
Yang Wang, Fang-Lei Zhang, Zhen-Jiang Liu, Zi-Jian Yao
Summary: A series of stable iridium complexes have been synthesized through a simple chemical method, and their high catalytic activity in reactions involving amines and alcohols, with water as the byproduct, has been demonstrated. These reactions provide a smooth route to synthesize various monoalkylated amine products at moderate temperatures with good to excellent yields.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Jia-Lu Sun, Huanfeng Jiang, Pierre H. Dixneuf, Min Zhang
Summary: A bifunctional cobalt single-atom catalyst has been developed for the direct synthesis of N,N'-diarylethane-1,2-diamines via selective reductive coupling of nitroarenes and formaldehyde. The catalyst exhibits good substrate compatibility, excellent reusability, and high step and atom efficiency. This work provides insights for developing more useful chemical transformations by controlling the nitroarene reduction to create specific building blocks in situ.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)