Article
Chemistry, Organic
Xin-Yang Lv, Ruben Martin
Summary: Here, the development of a copper-catalyzed C-(sp(3)) amination of unactivated secondary alkyl iodides mediated by diaryliodonium salts is described. The method involves the intermediacy of aryl radical species that undergo halogen atom transfer prior to interfacing with copper catalysts, enabling the formation of C-N bonds at sp(3)-hybridized carbons. The protocol is characterized by its mild reaction conditions, excellent regioselectivity, and wide substrate scope.
Review
Chemistry, Physical
Shidheshwar B. Ankade, Anand B. Shabade, Vineeta Soni, Benudhar Punji
Summary: This review summarizes the transition-metal-catalyzed alkylations of C-H bonds on various arenes and heteroarenes using unactivated alkyl halides until October 2020. The review is divided into two major sections based on the substrates utilized for alkylation: alkylation of arenes and alkylation of heteroarenes. Substantial progress has been made in direct alkylation using primary, secondary, and tertiary alkyl halides as well as methylation and fluoroalkylation.
Article
Chemistry, Multidisciplinary
Xiao-Long Su, Liu Ye, Ji-Jun Chen, Xiao-Dong Liu, Sheng-Peng Jiang, Fu-Li Wang, Lin Liu, Chang-Jiang Yang, Xiao-Yong Chang, Zhong-Liang Li, Qiang-Shuai Gu, Xin-Yuan Liu
Summary: The development of enantioconvergent cross-coupling of racemic alkyl halides with heteroarene C(sp(2))-H bonds has been achieved using a copper(I)/cinchona-alkaloid-derived N,N,P-ligand catalytic system, leading to high enantioselectivity of alpha-chiral alkylated heteroarenes, which show promise in drug discovery.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Xing-Wei Gu, Xiao-Feng Wu
Summary: Transition metal-catalyzed carbonylation of alkyl halides is an efficient method for synthesizing aliphatic carbonyl-containing compounds. This paper discusses recent developments in the carbonylation reactions of alkyl bromides and chlorides catalyzed by abundant metals.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Physical
Yanhong Liu, Aili Feng, Rongxiu Zhu, Chengbu Liu, Dongju Zhang
Summary: Density functional theory (DFT) calculations were performed to investigate the mechanism of copper-catalyzed four-component borocarbonylative coupling of alkenes with alkyl halides using bis(pinacolato)diboron as the boron reagent under CO atmosphere. The theoretical results revealed an unexpected reaction mechanism involving CuI as the sole catalyst, with a two-ligand relay mechanism and no radical participation, proceeding through SN2-type C-C coupling. The experimental observations of regio- and chemoselectivities, as well as the inhibition of the reaction by radical trapping reagents, were rationalized by the theoretical analysis.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Fengqian Zhao, Han-Jun Ai, Xiao-Feng Wu
Summary: In this study, a novel copper-catalyzed method has been developed for the highly selective double carbonylation of alkyl bromides, yielding moderate to good yields of alpha-keto amides as the sole products. Under different conditions, controllable double- and mono-carbonylation can be achieved with alkyl iodides.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xiaoyu Tong, Ze-Peng Yang, Carlos E. Del Angel E. Aguilar, Gregory C. Fu
Summary: This study reports an iron catalyst for cross-coupling reactions of alkyl electrophiles using olefins and hydrosilanes instead of alkylmetal reagents. Carbon-carbon bond formation occurs at room temperature, and the method utilizes commercially available components. Mechanistic studies suggest the generation of an alkyl radical from the alkyl electrophile and reversible elementary steps.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Jie Huang, Ling-Ling Chen, Tong-Mei Ding, Zhi-Min Chen
Summary: An efficient iron-catalyzed hydroarylation of 1,3-dienes with indoles has been developed for the first time. This protocol utilizes the green and inexpensive Earth-abundant metal iron as the catalyst. The reaction features convenience, mild conditions, and high atom utilization efficiency, allowing for the synthesis of various molecules containing alkenyl and indole groups.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Physical
Hiroki Akagawa, Naoki Tsuchiya, Asuka Morinaga, Yu Katayama, Michinori Sumimoto, Takashi Nishikata
Summary: This study reports the stereospecific Sonogashira coupling of a chiral alpha-bromocarboxamide with an alkyne, leading to the stereoretentive synthesis of a chiral tert-alkylated alkyne. The CuBr/bathophen catalyst system and carboxamide directing group are crucial for achieving high enantiospecificities in the couplings. Mechanistic studies reveal that the alkynyl copper species acts as the key intermediate, coordinating to the carboxamide group of the chiral alpha-bromocarboxamide.
Article
Chemistry, Physical
Hiroki Akagawa, Naoki Tsuchiya, Asuka Morinaga, Yu Katayama, Michinori Sumimoto, Takashi Nishikata
Summary: This paper reports the stereospecific Sonogashira coupling of a chiral alpha-bromocarboxamide with a tert-alkyl moiety and an alkyne, resulting in the synthesis of a chiral tert-alkylated alkyne in a stereoretentive manner. Both the CuBr/bathophen catalyst system and the carboxamide directing group are critical for achieving high enantiospecificities in the coupling reactions. Mechanistic studies reveal that the alkynyl copper species is the key intermediate that coordinates to the carboxamide group of chiral alpha-bromocarboxamide.
Article
Chemistry, Organic
Arti Ramani, Rachit S. Patil, Hussain Bhukya, Togati Naveen
Summary: We have developed a novel copper-catalyzed intermolecular alkyl formylation reaction of arene sulfonamides. This method is a significant advancement in the field as it eliminates the need for exogenous acid, base, or oxidant and can be completed within two hours. Various N,N-alkyl formylated sulfonamides were synthesized in moderate to good yields.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Yuta Sato, Akito Osada, Narihito Ogawa, Yuichi Kobayashi
Summary: The alkyl-alkyl coupling reaction of a secondary substrate with a nBuLi-based reagent utilizing Cu(OTf)(2) as a catalyst and soluble MgBr2·THF3 in THF as a transmetalation agent produced the desired coupling product in 74% yield. The use of soluble MgBr2·THF3 in THF was necessary for this reaction, and the method was successfully applied to other reagents as well. In contrast, the use of soluble MgCl2·THF2 in THF for the transmetalation of MeLi produced a reactive Me reagent that underwent a coupling reaction with inversion of the stereogenic carbon. Furthermore, this method allowed for the synthesis of (S)-14-methyloctadecan-2-one, a sex pheromone produced by lichen moths.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Yan-Ying Cui, Wen-Xin Li, Na-Na Ma, Chuanji Shen, Xiaocong Zhou, Xue-Qiang Chu, Weidong Rao, Zhi-Liang Shen
Summary: The direct cross-coupling of heterocyclic phosphonium salts with aryl bromides was successfully achieved at ambient temperature in THF using a nickel(ii) catalyst and other auxiliary reagents, providing an easy access to 4-arylated pyridine, quinoline, quinoxaline, and pyrazine.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Hai-Bin Yang, Xiao-Fang Jin, Hui-Ying Jiang, Wenwei Luo
Summary: A C(sp2)-C(sp2) bond was formed through a photoredox/N-heterocyclic carbene (NHC)-catalyzed radical cross-coupling reaction, presenting an alternative approach to traditional electron pair processes. This method demonstrated the first example of an NHC-catalyzed two-component radical cross-coupling reaction involving C(sp2)-centered radical species. The decarboxylative acylation of oxamic acid with acyl fluoride proceeded under mild conditions, enabling the synthesis of various useful alpha-keto amides, including sterically congested compounds.
Article
Chemistry, Organic
Mimi Xing, Huanhuan Cui, Chun Zhang
Summary: A novel nickel-catalyzed reductive cross-coupling method has been developed for constructing C-Si bonds under mild reaction conditions, allowing for the synthesis of structurally diverse organosilanes without Ni-catalyzed isomerization. The utility of this chemistry is demonstrated through further transformations of the product, while the radical mechanism of the reaction is elucidated through control experiments.
Article
Chemistry, Multidisciplinary
Sebastian Schaupp, Francisco J. Arriaza-Gallardo, Hui-jie Pan, Joerg Kahnt, Georgia Angelidou, Nicole Paczia, Kyle Costa, Xile Hu, Seigo Shima
Summary: In this study, an in vitro biosynthesis assay of the FeGP cofactor was conducted using cell extract of a specific bacterium, revealing that pyridinol derivatives 1, 2, and 3 are precursors of the FeGP cofactor, with the carboxy group of 3 being converted to the acyl ligand.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Wenhao Ren, Xin Tan, Chen Jia, Anna Krammer, Qian Sun, Jiangtao Qu, Sean C. Smith, Andreas Schueler, Xile Hu, Chuan Zhao
Summary: The researchers prepared a nickel single-atom/nanoparticle catalyst through direct solid-state pyrolysis, which exhibited high CO current density in an alkaline flow cell. Coupled with a nickel-iron anode in a zero-gap membrane electrolyzer, the catalyst achieved industrially relevant CO current density and low cell voltage, demonstrating a high overall energy efficiency.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Multidisciplinary
Zhikun Zhang, Srikrishna Bera, Chao Fan, Xile Hu
Summary: This article summarizes the importance of compounds rich in sp(3)-hybridized carbons in drug discovery, and introduces the nickel-catalyzed hydrocarbonation of alkenes as a potentially efficient method to synthesize these compounds. The article focuses on enantioselective reactions and provides a critical discussion of the state and challenges of the field.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Weiyan Ni, Teng Wang, Florent Heroguel, Anna Krammer, Seunghwa Lee, Liang Yao, Andreas Schueler, Jeremy S. Luterbacher, Yushan Yan, Xile Hu
Summary: This article introduces a nickel-based catalyst for the hydrogen oxidation reaction in hydroxide exchange membrane fuel cells and demonstrates its high performance. The catalyst consists of nickel nanoparticles embedded in a nitrogen-doped carbon support, and the electronic interaction between the nanoparticles and the support leads to balanced hydrogen and hydroxide binding energies, resulting in high catalytic activity. Hydroxide exchange membrane fuel cells employing this catalyst achieve a peak power density 6.4 times higher than previous best-performing fuel cells.
Article
Chemistry, Physical
Jun Gu, Shuo Liu, Weiyan Ni, Wenhao Ren, Sophia Haussener, Xile Hu
Summary: This study demonstrates that efficient CO2 electroreduction can be achieved in acidic medium by suppressing hydrogen evolution using alkali cations, overcoming the limitations caused by carbonate formation. The effects of cations are applicable to various catalysts and are achieved by modifying the electric field distribution and stabilizing key intermediates.
Article
Multidisciplinary Sciences
Yunchang Liang, Karla Banjac, Kevin Martin, Nicolas Zigon, Seunghwa Lee, Nicolas Vanthuyne, Felipe Andres Garces-Pineda, Jose R. Galan-Mascaros, Xile Hu, Narcis Avarvari, Magali Lingenfelder
Summary: This study utilizes chiral molecules to control spin polarization in oxygen evolution electrocatalysts, resulting in increased catalytic activity. Functionalization with chiral molecules allows for surpassing the limits of catalytic activity, providing new insights for optimizing catalyst performance.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Francisco J. Arriaza-Gallardo, Sebastian Schaupp, Yu-Cong Zheng, Mohd Farid Abdul-Halim, Hui-Jie Pan, Joerg Kahnt, Georgia Angelidou, Nicole Paczia, Xile Hu, Kyle Costa, Seigo Shima
Summary: This study reveals the functions of two enzymes, HcgA and HcgG, in the biosynthesis of the FeGP cofactor through in vitro complementation experiments and the use of purified enzymes. The results show that HcgA catalyzes the formation of 1, and HcgG is responsible for the reactions after the biosynthesis of 3. The data suggest that HcgG contributes to the formation of CO and completes the biosynthesis of the FeGP cofactor.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Wenhao Ren, Aoni Xu, Karen Chan, Xile Hu
Summary: A cation concentration gradient strategy is employed to enhance the activity and adjust the selectivity of CO2 electroreduction, breaking the linear scaling relationship of intermediate binding energies.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xingyu Wu, Nanjun Chen, Chuan Hu, Harm-Anton Klok, Young Moo Lee, Xile Hu
Summary: A fluorination strategy is reported to create a phase-separated morphological structure in poly(aryl piperidinium) anion-exchange membranes (AEMs). The fluorinated AEMs possess high conductivity and dimensional stability, as well as excellent mechanical and chemical stability. AEMFCs using these fluorinated AEMs achieve outstanding peak power density and remain stable over extended operation.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Miyeon Chang, Wenhao Ren, Weiyan Ni, Seunghwa Lee, Xile Hu
Summary: In this study, the effects of three different ionomers (Nafion, Sustainion-type XA-9, and poly(terphenyl piperidinium) (PTP)) on the electrochemical reduction of CO2 using Cu-based electrocatalysts were investigated. It was found that Nafion had little influence on the performance, XA-9 promoted CO formation, and PTP favored hydrogen and formate production. The observed effects were attributed to charge transfer and hydrophilicity/hydrophobicity of the ionomers. This study highlights the structure-sensitive nature of the ionomer-catalyst interaction in CO2RR.
Article
Chemistry, Physical
Srikrishna Bera, Chao Fan, Xile Hu
Summary: In drug discovery, the presence of aliphatic and chiral carbons in organic molecules increases their chances of clinical success. However, current methods for synthesizing chiral carbon-rich molecules have limitations and are not suitable for stereoselective synthesis using racemic reagents. This study presents a nickel-catalyzed hydroalkylation reaction that selectively forms one of the four possible stereoisomers, offering a promising approach for the stereoselective synthesis of carbon-rich molecules.
Article
Chemistry, Multidisciplinary
Weijin Wang, Ryo Tachibana, Zhi Zou, Dongping Chen, Xiang Zhang, Kelvin Lau, Florence Pojer, Thomas R. Ward, Xile Hu
Summary: In this study, manganese transfer hydrogenases based on the biotin-streptavidin technology were designed and developed for organic synthesis. These artificial enzymes exhibit high catalytic activity and enantioselectivity, and can be utilized for a wide range of substrates and functional groups.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Lara Lavrencic, Uttam Dhawa, Arthur Blumenstein, Xile Hu
Summary: Significant research efforts have been focused on the development of catalytic methods for lignocellulose depolymerization in the field of lignin biorefining. However, the conversion of obtained monomers into higher value-added products remains a key challenge in lignin valorization. In this study, copper-catalyzed reactions were utilized for benzylic functionalization of lignin-derived phenolics via the formation of hexafluoroisopropoxy-masked para-quinone methides (p-QMs). By controlling the rates of copper catalyst turnover and p-QM release, various unsaturated fragments suitable for further synthetic applications were successfully installed onto lignin-derived monomers.
Article
Chemistry, Physical
Weiyan Ni, Josephine Lederballe Meibom, Noor Ul Hassan, Miyeon Chang, You-Chiuan Chu, Anna Krammer, Songlan Sun, Yiwei Zheng, Lichen Bai, Wenchao Ma, Seunghwa Lee, Seongmin Jin, Jeremy S. Luterbacher, Andreas Schuler, Hao Ming Chen, William E. Mustain, Xile Hu
Summary: Hydroxide exchange membrane fuel cells (HEMFCs) are promising devices for energy conversion. Now, a porous nitrogen-doped carbon-supported PtRu catalyst for the hydrogen oxidation reaction is presented, consisting of Pt single atoms and PtRu nanoparticles that work synergistically. The catalyst enables a fuel cell that exceeds the US Department of Energy 2022 performance target.
Article
Chemistry, Physical
Wenhao Ren, Wenchao Ma, Xile Hu
Summary: Electrochemical CO reduction can be used to efficiently convert CO2 to chemical fuels. However, current membrane electrode assembly (MEA) CO electrolyzers suffer from low energy efficiency. This study shows that the transport of water and hydroxide ions at the quasi-two-phase interface of the cathode limits the performance of MEA electrolyzers at high current densities. By improving interfacial mass transport, the researchers achieved a lower cell voltage, higher stability, and higher Faradaic yield.
