Article
Polymer Science
Lei Wang, Pei Huang, Lei Huang, Chuanshuang Chen, Meiwei Qi, Wenfeng Jiang, Chunyang Yu, Shaodong Zhang, Yongfeng Zhou
Summary: A metal-free and visible light-initiated living cationic dark polymerization system has been demonstrated, which exhibits living characteristics and has potential for industrial applications.
Article
Chemistry, Organic
Kimberly M. Hilby, Scott E. Denmark
Summary: A Lewis base catalyzed, enantioselective sulfenocyclization of alkenes to afford [6,6]spiroketals has been developed with excellent yields and enantioselectivities. The method allows for rapid formation of highly substituted spiroketals using a chiral Lewis base catalyst and electrophilic sulfur source.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Energy & Fuels
Mingming Hao, Zhaohui Li
Summary: One-pot synergistic/cascade reactions are a promising direction for future catalysis, with increasing attention on utilizing solar light to initiate these reactions. Metal-organic frameworks (MOFs) are considered as promising multifunctional catalysts for light-initiated synergistic/cascade reactions due to their excellent photoactive activity and unique structural characteristics. This review summarizes recent developments on using MOFs for light-initiated one-pot synergistic/cascade reactions, highlighting the challenges and future prospects in developing smart multifunctional MOFs for these reactions.
Review
Chemistry, Multidisciplinary
Yubo Jiang, Ryan E. McNamee, Philip J. Smith, Ana Sozanschi, Zixuan Tong, Edward A. Anderson
Summary: Cascade reactions, also known as domino reactions, are a powerful means to construct multiple ring systems in a single step. This review discusses highlights in cascade polycyclizations applied to natural product syntheses over the last five years, including various processes such as pericyclic, ionic, metal-catalyzed, organocatalytic, and radical processes. Emphasis is placed on significant advancements in each field, such as photochemical and electrochemical methods, novel biomimetic routes, and enantioselective cascades.
CHEMICAL SOCIETY REVIEWS
(2021)
Article
Chemistry, Organic
Qinxuan Wang, Jiun-Le Shih, Ka Yi Tsui, Croix J. Laconsay, Dean J. Tantillo, Jeremy A. May
Summary: This study investigated various types of Huisgen cyclization or nitrene/carbene alkyne cascade reactions with different types of termination. Accessible nitrene precursors were evaluated, and carbonazidates were found to be the only effective initiators. The reaction outcome can be influenced by solvents, terminal alkynyl substituents, and catalysts. The mechanism was studied both computationally (using density functional theory) and experimentally, revealing relevant intermediates and plausible reaction pathways.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Julian Klepp, Thomas Bousfield, Hugh Cummins, Sarah V. A-M Legendre, Jason E. Camp, Ben W. Greatrex
Summary: This paper reports a novel aldol/Michael cascade reaction, which involves the reactions of aromatic aldehydes and levoglucosenone promoted by methoxide. The reaction yields bridged alpha,0-unsaturated ketones, with up to 91% yield in 14 examples. The formation of the bridged species is thermodynamically favored, except in the case of 5-methylfurfural and pyrrole-2-carboxaldehyde.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Eleonora Tufano, Euijae Lee, Matteo Barilli, Emanuele Casali, Andraz Ostrek, Hoimin Jung, Marta Morana, Jihye Kang, Dongwook Kim, Sukbok Chang, Giuseppe Zanoni
Summary: Ring-fused azacyclic compounds play a vital role in the synthesis of biorelevant natural products, pharmaceutical agents, and molecular materials. A new approach to synthesize these condensed azacycles with excellent stereoselectivity and functional group tolerance is presented in this study.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Wenxue Wang, Shouyang Feng, Yansheng Wei, Hongyu Wang, Yun Li
Summary: In this study, we disclose an iron-catalyzed method for the stereoselective synthesis of multisubstituted cyclic ketones containing synthetically challenging quaternary carbons. The cascade reaction involves a hydrogen atom transfer (HAT) process followed by a Dowd-Beckwith-type ring-expansion reaction. This strategic transformation provides access to valuable cyclic ketones bearing two contiguous stereocenters, including quaternary stereocenters, which are of paramount significance in synthetic chemistry.
Article
Chemistry, Organic
Wenxue Wang, Shouyang Feng, Yansheng Wei, Hongyu Wang, Yun Li
Summary: In this study, we report an iron-catalyzed method for the stereoselective synthesis of multisubstituted cyclic ketones. This method involves a cascade reaction initiated by a hydrogen atom transfer process and followed by a Dowd-Beckwith-type ring-expansion reaction. The strategic transformation allows access to valuable cyclic ketones with two contiguous stereocenters, including quaternary stereocenters, which are of paramount significance in synthetic chemistry.
Article
Astronomy & Astrophysics
Joseph R. Dwyer
Summary: Terrestrial gamma-ray flashes (TGFs) are powerful submillisecond bursts of gamma rays produced by thunderstorms. While most TGFs have been observed by spacecraft in low-Earth orbit, recent measurements have also detected TGFs on the ground. It is found that TGFs can be produced by positive leaders and may pose a radiation threat to aviation safety with doses exceeding 1 Sievert.
Article
Chemistry, Inorganic & Nuclear
Linkun Miao, Amir Yeganeh-Salman, Jason Yeung, Douglas W. Stephan
Summary: Efforts were made to deprotonate halophosphonium cations and generate various derivatives. It was found that one derivative is particularly effective in synthesizing methylene phosphonium cations. Additionally, differences in reactions with different types of olefins were observed, enhancing the synthetic methods for related compounds.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Applied
Yuyang Wu, Xincheng Jiang, Jiangya Ma, Jingbo Wen, Shuang Liu, Hongxia Liu, Huaili Zheng
Summary: A starch-based flocculant was synthesized using low-pressure ultraviolet initiation, which effectively removed humic acid from water across a wide pH range. The mechanism of flocculation was found to involve charge neutralization, adsorption, bridging, and patching between functional groups of the St-g-PDMC-LPUV flocculant and HA.
CARBOHYDRATE POLYMERS
(2021)
Review
Chemistry, Organic
Yun Shi, Ting Xiao, Dong Xia, Wenchao Yang
Summary: Fluorinated compounds are widely used in various fields due to their unique physical and chemical properties. The introduction of fluorinated functionalities into lead compounds has become a common strategy to enhance their properties. The trifluoromethylthio (SCF3) group, known for its high electronegativity and special lipophilicity, plays a crucial role in numerous fluorinated compounds. This article summarizes the recent progress in the cascade reaction of unsaturated hydrocarbons initiated by SCF3 radicals.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Polymer Science
Xia Lin, Jiajia Li, Jiandong Zhang, Shaoxiang Liu, Xiaofang Lin, Xiangqiang Pan, Jian Zhu, Xiulin Zhu
Summary: A living cationic polymerization of vinyl ethers was developed using electrophilic selenium reagents as initiators and pentacarbonylbromomanganese as the catalyst. This polymerization could be conducted under ambient conditions and yielded polymers with controlled molecular weights and narrow molecular weight distributions. The method also allowed for the introduction of different selenium-containing structures into the polymers.
Article
Chemistry, Organic
Hongpeng Bao, Yongjin Guo, Jiarong Shi, Yang Li
Summary: Two sets of cascade processes were achieved by benzyne insertion into the Se=O bond. The differential factors in these processes are the structures of diaryl selenium oxides and reaction conditions. When diaryl selenium oxides with an ortho weak Sigma- electron-withdrawing group were used, triarylselenonium salts were obtained at room temperature, while ortho-(aryloxy)phenyl phenyl selanes could be produced from diaryl selenium oxides at 100 degrees C.
Article
Chemistry, Multidisciplinary
Hajar Baguia, Gwilherm Evano
Summary: This study presents an efficient process for the copper-catalyzed direct perfluoroalkylation of C-H bonds in heteroarenes using commercially available perfluoroalkyl iodides. The combination of copper(I) iodide and 1,10-phenanthroline enables the easy reduction of perfluoroalkyl iodides to radical species that add to a wide range of heteroarenes, showcasing high regioselectivity. The efficiency and robustness of this process is demonstrated by the direct perfluoroalkylation of furan-containing peptides.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Maxime Artault, Kassandra Vitse, Agnes Martin-Mingot, Sebastien Thibaudeau
Summary: Under superacid conditions, aromatic amines can undergo direct and regioselective 1,1-difluoroethylation. In situ NMR studies at low temperatures confirmed the presence of key intermediates such as benzylic alpha-fluoronium and alpha-chloronium ions in the reaction. This method has a broad substrate scope and can be applied to the late-stage functionalization of natural alkaloids and active pharmaceutical ingredients.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Multidisciplinary Sciences
Clement Jacob, Hajar Baguia, Amaury Dubart, Samuel Oger, Pierre Thilmany, Jerome Beaudelot, Christopher Deldaele, Stefano Perusko, Yohann Landrain, Bastien Michelet, Samuel Neale, Eugenie Romero, Cecile Moucheron, Veronique Van Speybroeck, Cedric Theunissen, Gwilherm Evano
Summary: This study reports a general anti-Baldwin radical 4-exo-dig cyclization from nitrogen-substituted alkynes. Under visible light irradiation in the presence of a heteroleptic copper complex and an amine, a range of ynamides smoothly cyclize to the corresponding azetidines. The cyclization reaction shows full control of the regioselectivity, allowing the synthesis of useful building blocks in natural product synthesis and medicinal chemistry.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Gilles De Smet, Xingfeng Bai, Carl Mensch, Sergey Sergeyev, Gwilherm Evano, Bert U. W. Maes
Summary: This study demonstrates that acetate can serve as a renewable leaving group for selective deoxygenation of phenolics. The Ni-catalyzed reaction in a green solvent allows for efficient deoxygenation without affecting specific functional groups.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Yasmin Reviriot, Bastien Michelet, Rodolphe Beaud, Agnes Martin-Mingot, Frederic Guegan, Sebastien Thibaudeau, Jean Rodriguez, Damien Bonne
Summary: Enantioenriched complex fused-tricyclic azepanes or bridged-polycyclic azocanes were synthesized through a two-step sequence involving an enantioselective organocascade followed by superacid activation of the domino adduct, and the key steps and mechanism were described.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Chunyang Zhang, Nicolas Blanchard, Gwilherm Evano
Summary: An efficient radical cyclization of suitably functionalized ynamides to nitrogen-containing heterocycles is reported. The reaction shows high regio- and stereoselectivity, leading to good to excellent yields. Additionally, the exocyclic double bond can be used for further chemical diversification, and the generality of this radical cyclization is demonstrated by its extension to the synthesis of other nitrogen heterocycles.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Multidisciplinary
Bastien Michelet, Agnes Martin-Mingot, Jean Rodriguez, Sebastien Thibaudeau, Damien Bonne
Summary: Since the pioneer reports of the groups of Akiyama and Terada, the field of Bronsted acid organocatalysis has been continuously growing with the development of ingenious strategies for the activation of challenging substrates. Different approaches such as superacidic organocatalysts and the combination of Lewis and Bronsted acids have emerged, highlighting the complementarity of these strategies.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Omaima Adaoudi, Julie Le Bescont, Antoine Bruneau-Voisine, Gwilherm Evano
Summary: A general and inexpensive catalytic system for copper-catalyzed carbonylative coupling between alkyl iodides and alcohols or sodium hydroxide has been reported. Under mild pressure of carbon monoxide (5 bar) and catalytic amounts of copper(I) chloride and N,N,N',N?,N?-pentamethyldiethylenetriamine, a variety of secondary and tertiary alkyl iodides are easily converted into the corresponding esters and carboxylic acids without competing direct nucleophilic substitution. The main advantages of this procedure include broad applicability, the use of an especially inexpensive and available catalytic system, and user-friendliness.
SYNTHESIS-STUTTGART
(2023)
Review
Chemistry, Organic
Clement Jacob, Julien Annibaletto, Bert U. W. Maes, Gwilherm Evano
Summary: This review article presents and discusses the regioselectivity of the direct arylation reactions of anilines, focusing on the ortho, meta, and para positions. These reactions provide a straightforward method for the synthesis of arylated anilines without prefunctionalization. The factors influencing the reactivity and selectivity of these reactions are also emphasized.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Multidisciplinary
Anthony J. Fernandes, Bastien Michelet, Armen Panossian, Agnes Martin-Mingot, Frederic R. Leroux, Sebastien Thibaudeau
Summary: Understanding the impact of emerging fluorinated motifs is crucial due to the increasing use of fluorine in various fields. This study demonstrates the significant effect of a local partial charge inversion through the replacement of a CHCH3 group with a CFCF3 group. This strategy enables the diastereoselective reduction of 5-membered ring oxocarbenium ions, leading to the formation of highly substituted tetrahydrofurans.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Maxime Artault, Thomas Cantin, Melissa Longuet, Kassandra Vitse, Christ Daniel Matatu Mbengo, Frederic Guegan, Bastien Michelet, Agnes Martin-Mingot, Sebastien Thibaudeau
Summary: This study reports a method to reorganize the core structure of aliphatic unsaturated nitrogen-containing substrates by exploiting polyprotonation in superacid solutions. The superelectrophilic activation of N-isopropyl systems allows for the selective functionalization of nitrogen-containing substrates. It is demonstrated that this skeletal reorganization can be controlled through protonation interplay.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Fabiana Siragusa, Thomas Habets, Raphael Mereau, Gwilherm Evano, Bruno Grignard, Christophe Detrembleur
Summary: This study presents a new type of degradable polymer that can be easily and completely degraded into its monomers under mild conditions through catalyst-free aminolysis. The recovered monomers can then be used for polymer synthesis, offering a closed-loop recycling scenario. This work is of great significance for addressing the accumulation of post-consumer plastic waste and providing building blocks for the synthesis of novel degradable polymers.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Swetha Jos, Christine Tan, Pierre Thilmany, Alaa Saadane, Carla Slebodnick, Gwilherm Evano, Webster L. Santos
Summary: We have reported a tri-n-butyl phosphine catalyzed hydroboration reaction of ynamides, which provides regio- and stereo-selective formation of (Z)-beta-borylenamides in good yields. Surprisingly, a formal cis addition to the triple bond was observed, and this finding was confirmed by NMR and X-ray crystallography. P-31 NMR studies suggest that a zwitterionic vinylphosphonium intermediate plays a key role in the reaction mechanism. Furthermore, the resulting products were successfully transformed into beta-CF3 enamides via stereoretentive trifluoromethylation.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Aline Delamare, Guillaume Naulet, Brice Kauffmann, Gilles Guichard, Guillaume Compain
Summary: The hexafluoroisobutyl group is a commonly found hydrophobic group in drugs, and its introduction can provide new advantages to compounds. However, the lack of a general and practical synthetic methodology has hindered the exploration of this modification. In this study, the first general method for introducing the hexafluoroisobutyl group into various compounds was reported. This method overcomes the usual fluoride beta-elimination observed with other CF3-vinyl groups, and it has been successfully applied to the multigram-scale synthesis of enantiopure (S)-5,5,5,5',5',5'-hexafluoroleucine.
Article
Chemistry, Multidisciplinary
Hajar Baguia, Jerome Beaudelot, Cecile Moucheron, Gwilherm Evano
Summary: An efficient and general process for the direct perfluoroalkylation of C-H bonds in heteroarenes using copper catalysis has been reported. The reaction is photoinduced and operates at room temperature, making it a redox neutral process.
CHEMICAL COMMUNICATIONS
(2022)
