Article
Chemistry, Multidisciplinary
Arnar Guomundsson, Srimanta Manna, Jan-E. Backvall
Summary: This study reports the first Fe-II-catalyzed aerobic biomimetic oxidation of amines, which involves multiple electron transfer steps and is inspired by biological oxidation in the respiratory chain. The use of two coupled catalytic redox systems helps lower the energy barrier and improve the selectivity of the oxidation reaction. Various primary and secondary amines were successfully oxidized in air to their corresponding aldimines or ketimines in good to excellent yield.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Jisun Baek, Tengda Si, Hun Young Kim, Kyungsoo Oh
Summary: A biomimetic ADH-like oxidation protocol using an ortho-naphthoquinone catalyst and a catalytic amount of base has been developed. The organocatalytic aerobic oxidation proceeds through intramolecular 1,5 hydrogen atom transfer, which is mechanistically distinctive from previous ADH mimics that require metals as catalysts. This ADH-like oxidation protocol provides a green alternative to existing stoichiometric and metal-catalyzed alcohol oxidation reactions.
Article
Chemistry, Organic
Jiaxing Chen, Yongzhuo Xu, Wen Shao, Jianhua Ji, Boqiang Wang, Muyang Yang, Guojiang Mao, Fuhong Xiao, Guo-Jun Deng
Summary: A Pd-catalyzed C-O cross-coupling reaction was reported, which allows for the synthesis of highly congested hydroxylamines with an α-quaternary carbon center without cleavage of the N-O bond. This strategy shows high chemoselectivity, broad substrate scope, and excellent functional group tolerance, and has been demonstrated by pharmaceutical derivatization and postcatalytic modifications.
Article
Multidisciplinary Sciences
Cheng Wang, Zirui Qiao, Yulan Tian, Haijun Yang, Huaqiang Cao, Anthony K. Cheetham
Summary: Imines can be synthesized directly from phenylmethanol and ben-zylamine (or aniline) using carbon nanostructures as metal-free catalysts, yielding imines with up to 98% yield and water as the only by-product. The catalytic mechanism involves the reduction of O-2 to O-2(center dot-) by the unpaired electrons in carbon catalysts, triggering the oxidative coupling reaction to form imines, while the holes in the carbon catalysts receive electrons from the amine to restore the spin states. This work provides a new avenue for synthesizing carbon catalysts and has great potential for industrial applications.
Article
Chemistry, Organic
Taiga Yurino, Sunaho Saito, Mizuki Ichihashi, Takeshi Ohkuma
Summary: A Pd(OAc)(2)/P(OPh)(3) combination catalyst was used for the Tsuji-Trost-type allylic amination under aerobic conditions, and it was found that the reaction proceeded efficiently only when allylic phosphates were employed as electrophiles.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Binglan Wu, Xueying Zhan, Peng Yu, Jun Meng, Marshet Getaye Sendeku, Fekadu Tsegaye Dajan, Ning Gao, Wenjia Lai, Ying Yang, Zhenxing Wang, Fengmei Wang
Summary: A novel In4/3P2Se6 nanosheet photocatalyst was synthesized and found to exhibit high yield and selectivity for the simultaneous production of hydrogen gas and N-benzylidenebenzylamine in water and acetonitrile solvents.
Review
Chemistry, Multidisciplinary
Alexios G. Stamoulis, David L. Bruns, Shannon S. Stahl
Summary: This Perspective analyzes the thermodynamic principles underlying catalytic aerobic oxidation reactions and borrows concepts from the study of the oxygen reduction reaction (ORR) in fuel cells. The central role of catalyst overpotential in guiding the development of aerobic oxidation reactions is highlighted. Applications and implications of these concepts are discussed through case studies.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Decai Huang, Hao Sun, Jingwen Li, Junhao Zheng, Darun Yang, Guozhu Chen, Daowei Gao, Huaiqing Zhao
Summary: The heterogeneous BPDC-RuO2-CeO2 catalyst derived from Ce-BPDC MOFs can efficiently catalyze the oxidation of amines under mild conditions, and it can be recycled for up to six times without significant loss of catalytic activity.
Article
Chemistry, Physical
Zhiming Ma, Shiqiang Liu, Nanfang Tang, Tao Song, Ken Motokura, Zhemin Shen, Yong Yang
Summary: The coexistence of Fe nanoclusters and Fe single atoms in N-doped porous carbon can significantly enhance the catalytic performance in the aerobic oxidation of primary amines to imines.
Article
Chemistry, Multidisciplinary
Zhuo-Ya Mao, Xiao-Di Nie, Yi-Man Feng, Chang-Mei Si, Bang-Guo Wei, Guo-Qiang Lin
Summary: The Cu(OTf)(2) catalyzed Ugi-type reactions of N,O-acetals with isocyanides were described for the synthesis of pyrrolidinyl and piperidinyl 2-carboxamides, providing high diastereoselectivities for 4-hydroxy-5-substituted-prolinamides (2,4-cis/trans > 19:1) and proposing a stereoselective model for 2,4-cis selectivity. Additionally, a novel analog of the VHL ligand, 4-F-VH 032, was conveniently obtained using this method.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Takuya Takashima, Hamdiye Ece, Taiga Yurino, Takeshi Ohkuma
Summary: A new methodology for the synthesis of α-amino nitriles through oxidative cyanomethylation of amines was developed. Nitromethane was used as the methylene source, and Me3SiCN was present without the requirement of an external oxidant. The reaction was catalyzed by AgCN and promoted by a stoichiometric amount of LiBF4. Various amines, including both aromatic and aliphatic compounds, which are usually sensitive to oxidative conditions, could be used in the reaction.
Article
Chemistry, Organic
Shi-Yi Yuan, Qi-Qi Yan, Dan Wang, Ting-Ting Dan, Long He, Cheng-Yu He, Wen-Dao Chu, Quan-Zhong Liu
Summary: A new method for the asymmetric synthesis of 3-methyleneindolines from alkynyl imines has been developed via a rhodium-catalyzed tandem process, which shows unconventional chemo-selectivity and provides products with high yields and enantioselectivities under mild reaction conditions, perfect atom economy, and a broad substrate scope.
Review
Chemistry, Organic
Hun Young Kim, Kyungsoo Oh
Summary: This review highlights the interplay between copper catalysts and molecular oxygen in controlling aerobic C-sp(3)-H bond oxidations. Specifically, it focuses on the Cu-catalyzed oxidations of benzylic, alpha-carbonyl, and amine group adjacent carbons over the past five years. Furthermore, discussion on the development of tandem multicomponent reactions utilizing aerobic C-sp(3)-H bond oxidations underscores the importance of controlled catalyst behaviors and interactions between multiple reaction components.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Tengda Si, Hana Cho, Hun Young Kim, Kyungsoo Oh
Summary: This study developed the catalytic diazotization of aryl amines using ortho-naphthoquinone catalyst under aerobic conditions, with 2-nitropropane as a source of nitrosonium ion. The catalytic generation of diazonium species from aryl amines was further explored in the hydrode-diazotization to yield the corresponding products. Mechanistic studies revealed the involvement of aryl radical species, which readily underwent radical cyclization to form alkenes and halogen abstraction reactions.
Article
Chemistry, Physical
Yao Fang, Xuhui Wei, Haifeng Liu, Shugong Gao, Kun Jia, Junwei Wang, Jiazang Chen
Summary: The correlation between photoinduced hole extraction and the Fermi level promotes the mineralization of contaminants by facilitating electron transfer from a semiconductor to the solution. We have developed a fixed-bed photocatalyst based on a homogeneous contact that enhances oxygen reduction through interfacial electron transfer and collision between dissolved oxygen and catalytic sites. This photocatalyst configuration also reduces competitive light absorption by contaminants and cocatalysts. The efficient electron transfer synergistically promotes the generation of hydroxyl radicals for mineralization.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
