Article
Chemistry, Organic
Miro Halaczkiewicz, Harald Kelm, Georg Manolikakes
Summary: This article describes a stereoselective synthesis of isoindolo[2,1-a]quinolin-11(5H)-ones that contain three contiguous stereogenic centers. The desired fused heterocyclic isoindolinones are obtained in high yields and diastereoselectivities through a Lewis-acid mediated reaction of enamides with N-aryl-acylimines. The scope and limitations of this method are discussed. The stereochemical outcome of this transformation indicates a stepwise reaction pathway.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Meng-Fan Li, Shao-Qing Shi, Ting Xu, Qian Zhang, Wen-Juan Hao, Shu-Liang Wang, Jianyi Wang, Shu-Jiang Tu, Bo Jiang
Summary: A new method for the synthesis of tricyclic bridged-fused benzo[d]azepines has been developed through an organocatalytic double annulation cascade. The reaction involves the scission/recombination of N-O bonds of nitrones and has demonstrated moderate to good yields and complete diastereoselectivity. Density functional theory calculations were used to gain insight into the formation of diradical intermediates.
CHINESE CHEMICAL LETTERS
(2023)
Article
Chemistry, Organic
Yunpeng Zhang, Daoyi Yang, Dengfu Lu, Yuefa Gong
Summary: A photoredox-enabled alkylative dearomatization of protected anilines is described. By using Ir catalyst and light irradiation, an N-carbamoyl-protected aniline and an alpha-bromo-carbonyl compound can be activated simultaneously, leading to the formation of a dearomatized cyclohexadienone imine as the main product through radical recombination. This method allows the preparation of a series of imines with contiguous quaternary carbon centers, which can be further converted into cyclohexadienones, cyclohexadienols, and cyclohexyl amines.
Article
Chemistry, Multidisciplinary
Tessa Lynch-Colameta, Sarah Greta, Scott A. Snyder
Summary: This study presents a simple method for synthesizing a variety of products containing aza-quaternary centers by activating ketonitrones. The reaction process is mild, fast, and high-yielding, suitable for a diverse range of substrates, including those with electron-deficient substituents. Additionally, a catalytic asymmetric version has been developed, achieving good levels of enantioselectivity for several ketonitrones.
Article
Chemistry, Multidisciplinary
Ze-Jie Lv, Wei Liu, Wen-Xiong Zhang
Summary: As key intermediates in metal-promoted/catalyzed C-C bond coupling reactions of nitriles and alkynes, azametallacyclopentadienes, M(N=CR1-CR2=CR3), are an important class of azametallacycles. Research on their solid-state structures, intrinsic reactivity, and synthetic application was limited until the beginning of this century when they were found to have applications in the synthesis of heterocycles. Since then, various complexes with this motif have been isolated and characterized, including rare-earth azametallacyclopentadienes which show high reactivity towards unsaturated molecules.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Biochemistry & Molecular Biology
Joana L. C. Sousa, Helio M. T. Albuquerque, Armando J. D. Silvestre, Artur M. S. Silva
Summary: Betulinic acid was used as a starting material to synthesize a library of novel BA-derived compounds containing O- and N-heterocycles. Remarkably, the triterpene acts as a diastereoselective inducer in nitromethane conjugate addition reaction, and can also incorporate other heterocycles into its molecular structure using simple synthetic methods.
Article
Chemistry, Multidisciplinary
Jenna L. Miller, Krishnan Damodaran, Paul E. Floreancig
Summary: This manuscript describes a protocol to form acyliminium ions and related species through hydride abstractions of easily accessible allylic carbamates, amides, and sulfonamides. These intermediates are used in the synthesis of nitrogen-containing heterocycles, demonstrating high levels of stereocontrol. Areas of investigation include oxidation efficiency, geometry of intermediate iminium ions, substrate stereocenter impact on stereocontrol, and transition state geometry.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Davit Hayrapetyan, Valeriya Stepanova
Summary: In this study, spirocyclic pyrrolidones and piperidones were synthesized via [3+2]- and [3+3]-aza-annulation reactions starting from readily available alpha-ketolactones and alpha-ketolactams. The annulation reactions proceeded with good yields and excellent diastereoselectivity, creating one C-C and two C-N bonds, as well as three new stereocenters in a fast and efficient manner.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Chemistry, Physical
Gaole Dai, Tingting Wu, Hui Chen, Yu Zhao
Summary: This review presents recent advances in the use of redox-active organics with quaternary nitrogen redox centers as electrode materials for batteries, focusing on molecular design. Challenges and potential solutions for the application of organic materials in battery cathodes are also discussed from the perspective of cell chemistry.
CURRENT OPINION IN ELECTROCHEMISTRY
(2021)
Article
Chemistry, Organic
Arko Das, Harshit Joshi, Vinod K. Singh
Summary: An enantioselective approach for synthesizing fluorinated azaarenes with vicinal quaternary-tertiary stereocenters has been summarized, utilizing a chiral copper(I)-phosphine complex to bind with the azaarenes followed by Michael addition to unsaturated acyl imidazoles, resulting in highly enantioselective compounds with excellent yields. Further functionalization of the acyl imidazole part has also been demonstrated.
Article
Chemistry, Organic
Salem El Kharrat, Philippe Laurent, Laurent Boiteau
Summary: Novel 2-perfluoroalkylmethyl,4-arylamino substituted tetrahydroquinolines were efficiently synthesized using perfluoroalkyl iodides and monosubstituted anilines. The reaction proceeded through radical bis-addition, Michael addition, and electrophilic aromatic substitution, leading to the target compounds with different substitution patterns.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Nicolas Muller, Benedikt S. Schreib, Sebastian U. Leutenegger, Erick M. Carreira
Summary: In this study, the palladium-catalyzed aminoalkynylation of electronically unbiased olefins with iodoalkynes was reported. Using the picolinamide auxiliary, the syn-selective aminoalkynylation of mono-, di-, and trisubstituted alkenes was achieved, leading to the formation of corresponding pyrrolidines in high yield and single diastereomers. The picolinamide also allowed for the rapid synthesis of functionalized olefins and subsequent Pictet-Spengler reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Chloe G. Williams, Sepand K. Nistanaki, Conner W. Wells, Hosea M. Nelson
Summary: This paper presents a methodology for the construction of sterically congested quaternary centers by trapping vinyl carbocations with silyl ketene acetals. This main group-catalyzed α-vinylation reaction is advantageous due to limited methods for accessing these congested motifs. Furthermore, β, γ-unsaturated carbonyl moieties and tetrasubstituted alkenes are commonly found in bioactive natural products and pharmaceuticals, and this catalytic platform provides a simple and cost-effective means of synthesizing them.
Article
Chemistry, Multidisciplinary
Vladimir V. Voronin, Mikhail V. Polynski, Maria S. Ledovskaya
Summary: A novel synthetic approach has been developed for the synthesis of 2,3,6-trisubstituted pyridines, their deuterated derivatives, and doubly-labeled pyridines. The method involves the catalyst-free [4+2] cycloaddition of 1,2,4-triazines and in situ generated acetylene or labeled acetylene.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Applied
Rayhane Hammami, Pascale Maldivi, Christian Philouze, Sebastien Carret, Benjamin Darses, Soufiane Touil, Jean-Francois Poisson
Summary: A variety of 4-phosphinylpyrrolidin-3-ones were synthesized via a [3+2] cycloaddition reaction between aryl aldonitrones and phosphinylallenes. The products were obtained as unique 4,5-trans diastereomers in yields ranging from 47% to 80% for 23 examples. Chiral racemic allenes exhibited a moderate 2:1 to 4:1 2,5-diastereoselectivity. Under the reaction conditions, the cycloadducts undergo a rearrangement to selectively afford the corresponding pyrrolidin-3-ones. DFT calculations provided insights into the mechanism involving the homolytic cleavage of the N-O bond of the cycloadduct.
ADVANCED SYNTHESIS & CATALYSIS
(2023)