Article
Chemistry, Organic
Xin Hu, Qiang Bian, Zheng-Lin Wang, Lin-Jie Guo, Yi-Ze Xu Ge Wang, Da-Zhen Xu
Summary: A four-component reaction strategy has been developed for access to acyclic nitrile-substituted all-carbon quaternary centers efficiently. By using DABCO-based ionic liquid catalyst, the reactions proceed smoothly under mild conditions, with water as the only byproduct. Some of the products exhibit excellent activity against specific fungi.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Zong-Wang Qiu, Liang Long, Zhi-Qiang Zhu, Hong-Fu Liu, Han-Peng Pan, Ai-Jun Ma, Jin-Bao Peng, Yong-Heng Wang, Hao Gao, Xiang-Zhi Zhang
Summary: This study reports an efficient metal-free method for constructing acyclic all-carbon quaternary stereocenters. The asymmetric catalytic visible-light-induced Paterno-Buchi cycloaddition/electrocyclic ring-opening/alpha-selective arylation reactions of alpha,beta-unsaturated carbonyl compounds were successfully achieved via a well-designed reaction cascade. The method is applicable to a wide range of compounds and provides access to synthetically useful building blocks.
Article
Chemistry, Organic
Xueyang Liu, Jean-Marc Pons, Valerie Monnier, Laurence Charles, Adrien Quintard, Cyril Bressy
Summary: This paper describes an efficient enantioselective kinetic resolution method for the separation of secondary alcohols with a quaternary stereocenter. It utilizes a commercially available chiral isothiourea organocatalyst and achieves high levels of stereoselectivity in a wide range.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Cedric Hervieu, Mariia S. Kirillova, Tatiana Suarez, Marco Mueller, Estibaliz Merino, Cristina Nevado
Summary: This study reports an asymmetric radical sulfinyl-Smiles rearrangement method to access acyclic amides with alpha-all-carbon quaternary centers. It uses enantioenriched N-arylsulfinyl acrylamides as acceptors for a variety of radicals produced in situ under mild photoredox conditions. The resulting amides are prevalent in pharmaceuticals, agrochemicals, and bioactive natural products, and can be further transformed into valuable chiral compounds.
Article
Chemistry, Organic
Oceane Flores, Patrick Wagner, Jean Suffert
Summary: Exploration of 4-exo-dig cyclocarbopalladation in the discovery of new and original scaffolds resulted in unexpected findings, including the identification of polycyclic molecules with a tetrasubstituted carbon. The presence of a triple bond substituting the cyclohexene ring on the starting compound was found to be crucial for high stereoselectivity. This observation was confirmed by the reaction of a nonsubstituted cyclohexene ring, which led to poor stereoselectivity and low yields.
Article
Chemistry, Organic
Jinyu Zhang, Bin Lu, Zhaoliang Ge, Le Wang, Xiaoming Wang
Summary: A novel [Rh]2-catalyzed three-component reaction has been developed for the synthesis of C3 substituted indoles bearing all-carbon quaternary centers. This reaction involves a relay carbene-induced C-H functionalization and allylic alkylation process, showing good atom and step economy. Enantioselective control is achieved using a specific ligand, providing an efficient method for constructing enantioenriched indole derivatives with an all-carbon quaternary stereocenter.
Article
Chemistry, Multidisciplinary
Phillippa Cooper, Andrew G. Dalling, Elliot H. E. Farrar, Timothy P. Aldhous, Simon Grelaud, Eleanor Lester, Lyman J. Feron, Paul D. Kemmitt, Matthew N. Grayson, John F. Bower
Summary: The Ir-catalyzed alkene hydroarylation allows for the efficient synthesis of quaternary benzylic centers, and the structural features of the ligand play a crucial role in the reaction efficiency.
Article
Chemistry, Multidisciplinary
Junqiang Wei, Vincent Gandon, Ye Zhu
Summary: Synthetic application of asymmetric catalysis requires strategic alignment of bond construction and chiral target molecule creation. Remote desymmetrization offers advantages in spatial decoupling of catalytic transformation and generation of stereogenic element. However, this spatial separation presents challenges for chiral catalysts to discriminate distant enantiotopic sites several bonds away from a prochirality center.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Ryan A. Kozlowski, Hanh T. Nguyen, Michael E. Lehman, Christopher D. Vanderwal
Summary: The esters of salicylic acid derivatives can undergo Birch reduction and diastereoselective alkylations to form methoxycyclohexadienes with new quaternary stereogenic centers. The use of ester-based auxiliaries is an improvement over prolinol-derived amides, which are expensive and difficult to cleave.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Chuxiong Peng, Fengyan Gu, Xiaofeng Lin, Ning Ding, Qichen Zhan, Peng Cao, Tao Cao
Summary: By reacting readily available cyclopropenes with sulfonyl iodides in water, beta-iodo cyclopropyl sulfones were selectively formed, which are important 3C starting materials with privileged structures in medicinal chemistry. This method is operationally convenient and environmentally friendly with water as the sole solvent, avoiding transition metals and air-sensitive reagents, and chromatography-free purification. It can be extended to various styrenes and alkynes, with excellent anti-addition selectivity in reactions with alkynes. Additionally, it has been successfully applied in the post-modification of natural products and drugs, as well as the synthesis of quinolinone MAT2A inhibitor and dipeptide renin inhibitor.
Article
Chemistry, Multidisciplinary
Wusheng Guo, Linhong Zuo, Manying Cui, Biwei Yan, Shaofei Ni
Summary: The propargylic amination approach towards chiral acyclic alpha-quaternary alpha-amino ketones described in this study utilizes a Cu-catalyzed procedure with commercially available amines as nucleophiles. The use of rationally designed propargylic cyclic carbonates as substrates is key to the success, as they can generate a Cu-bonded enolate zwitterionic intermediate upon decarboxylation. This method demonstrates high asymmetric induction and wide functional group tolerance, representing a significant advancement in the challenging synthesis of acyclic chiral alpha-quaternary alpha-amino ketones.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Doohyun Baek, Huijeong Ryu, Hyungwoo Hahm, Junseong Lee, Sukwon Hong
Summary: A highly enantioselective route to beta-quaternary (5-lactams) was described using palladium/pyridine-dihydroisoquinoline (PyDHIQ)-catalyzed conjugate arylations. The effect of pi-interactions on the enantioselectivity was elucidated, and the PyDHIQ ligand was found to play a crucial role in determining the enantioselectivity through attractive noncovalent interactions with substrates. The methodology was successfully applied to the asymmetric formal synthesis of (-)-picenadol.
Article
Chemistry, Multidisciplinary
Wei Wang, Fangqing Zhang, Yangbin Liu, Xiaoming Feng
Summary: In this study, we report a novel method using a bimetallic catalyst for the asymmetric allylation of challenging trisubstituted allylic esters, achieving the construction of vicinal all-carbon quaternary stereocenters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Joshua A. Malone, Satish Chandra Philkhana, Jacob R. Stepherson, Fatimat O. Badmus, Frank R. Fronczek, Rendy Kartika
Summary: This article describes a new synthetic reaction that can generate all-carbon bisquaternary centers at the opposing side of alpha-carbons in cyclohexanone with four different substituents in a controlled manner.
Article
Chemistry, Multidisciplinary
Dong -Kai Wang, Liu-Bin Li, Fa-Liang Liu, Hui Qiu, Jiao-Zhe Li, Jianfeng Zhang, Chao Deng, Wen-Ting Wei
Summary: This study presents a novel method for the construction of all-carbon quaternary centers, specifically those with an alkyne-substituted framework, using a Fe-catalyzed formal insertion of diazo compounds into C(sp)-C(sp(3)) bonds of propargyl alcohols under mild conditions.
ACS CENTRAL SCIENCE
(2022)
Article
Chemistry, Applied
Claire Laye, Jonathan Lusseau, Frederic Robert, Yannick Landais
Summary: The reduction of phosphine oxides into phosphines using PhSiH3 and Ph3C+[B(C6F5)(4)](-) is highly efficient and yields a broad range of secondary and tertiary alkyl and arylphosphines with various functional groups. The reaction is believed to proceed through the generation of a silyl cation and subsequent reduction by the silane.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Anthony J. Fernandes, Frederic Robert, Yannick Landais, Sandra Kuenzler, Thomas Mueller
Summary: By utilizing NMR and XRD studies supported by DFT calculations, the structure determination of a series of biphenylsilyloxonium cations was carried out, providing insights into the origin of oxygen pyramidalization in biphenyl and binaphthylsilyl oxoniums. The low barrier of inversion in the oxygenyl series suggests the significant role of the biaryl axis in the inversion of configuration at the oxygen center.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Nivesh Kumar, Claire Laye, Frederic Robert, Yannick Landais
Summary: Heteroarylsilyl cations derived from a quinoline skeleton exhibit high stability and interactions reinforced by substituents at the C4 position on the quinoline ring. DFT calculations and experimental data demonstrate the relatively high Lewis acidity of these silylium ions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Quentin Sobczak, Aravindu Kunche, Damien Magis, Daiann Sosa Carrizo, Karinne Miqueu, Jean-Marc Sotiropoulos, Eric Cloutet, Cyril Brochon, Yannick Landais, Daniel Taton, Joan Vignolle
Summary: The research demonstrates that mono- and bis-acyclic amino(aryl)carbenes selectively dimerize to form diaminoalkenes and previously unknown amino-containing poly(p-phenylene vinylene)s. By a simple protonation reaction, the physico-chemical properties of these polymers with amino groups in the α-position of C=C double bonds can be manipulated in different ways.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Iman Traboulsi, Nitin S. Dange, Vincent Pirenne, Frederic Robert, Yannick Landais
Summary: The total enantioselective synthesis of (+)-eucophylline 1 was achieved using a chiral piperidinone as a key structural motif. The synthesis involved two strategies, carbo-cyanation and sulfonyl-cyanation, starting from enantiopure cyclopropenes and cyclobutenes. The final compound was obtained in 17 steps and with an overall yield of 5.9% from 1,1-dibromobutene.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Ikechukwu Martin Ogbu, Gulbin Kurtay, Margaux Badufle, Frederic Robert, Carlos Silva Lopez, Yannick Landais
Summary: The PIDA-mediated oxidative decarboxylation of oxamic acids in the presence of alcohols is shown to afford the corresponding urethanes under thermal conditions. Computational and experimental mechanistic exploration allows to rationalize the different reactivity of PIDA as compared to related cyclic BI-OAc and highlights the importance of the enhanced acidity of the proton in the carbamoyl radical intermediate.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Shuai Liu, Frederic Robert, Yannick Landais
Summary: Dual Ni and Ir catalysis allows the visible-light-assisted synthesis of arylsilanes without the need for strong bases, high temperature, and air/moisture sensitive reagents, resulting in moderate to good yields.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Ikechukwu Martin Ogbu, Dario M. Bassani, Frederic Robert, Yannick Landais
Summary: Photocatalyzed oxidative decarboxylation of oxamic acids under near-infrared irradiation using Os(bptpy)(2)(PF6)(2) as catalyst is reported. The reaction was applied to the synthesis of urethanes and heterocyclic amides. Mechanistic studies and comparative penetration depths between the NIR and the visible light mediated processes are discussed.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Ikechukwu Martin Ogbu, Gulbin Kurtay, Frederic Robert, Yannick Landais
Summary: This review article highlights the recent developments in the chemistry of carbamoyl radicals generated from oxamic acids. These radicals are efficiently and mildly generated through oxidative decarboxylation of oxamic acids using various methods. The generated carbamoyl radicals can further react with unsaturated systems to produce a wide range of important amides. Additionally, this method allows for the straightforward preparation of urethanes, ureas, and thioureas.
CHEMICAL COMMUNICATIONS
(2022)
