Article
Chemistry, Organic
Stefano Barranco, Federico Cuccu, Dayi Liu, Sylvie Robin, Regis Guillot, Francesco Secci, Valerie Brenner, Michel Mons, Pierluigi Caboni, David J. Aitken, Angelo Frongia
Summary: A new method for the stereoselective one-pot double derivatization of cyclobutene-1-carboxylic acid has been developed. This method involves a mild organic base catalyzed amidation/aza-Michael addition of benzo[d]oxazol-2(3H)-ones, leading to the formation of novel beta-N-heterocyclic cyclobutane carboximide derivatives with a trans geometry. The carboximide moiety can react smoothly with nucleophiles, providing access to diverse derivatives of trans-beta-N-heterocyclic cyclobutanecarboxylic acid, including peptidomimetic structures.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Yuri Saito, Jun Kikuchi, Chen Wang, Naohiko Yoshikai
Summary: We report the design and development of Co/Al and Co/Mg bimetallic catalysts supported by a phosphine/secondary phosphine oxide (PSPO) bifunctional ligand for the selective C-H alkenylation of nitrogen-containing heteroarenes with alkynes. These catalysts enable the alkenylation of pyridine, pyridone, and imidazo[1,2-a]pyridine derivatives at the C-H site proximal to the Lewis basic nitrogen or oxygen atom, with a selectivity profile distinct from previously developed cobalt-diphosphine/aluminum catalyst. The alkenylated products were obtained in moderate to good yields using various heterocycles and differently substituted internal alkynes. Kinetic isotope effect experiments suggest the irreversibility of the C-H activation step, the relevance of which to the rate-limiting step depends on the reaction conditions. Density functional theory calculations indicate that ligand-to-ligand hydrogen transfer is the common mechanism of C-H activation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Thomas Hansen, Pascal Vermeeren, Ryoji Yoshisada, Dmitri Filippov, Gijsbert A. van der Marel, Jeroen D. C. Codee, Trevor A. Hamlin
Summary: In this study, the Lewis acid-catalyzed epoxide ring-opening reactions were investigated using relativistic dispersion-corrected density functional theory. It was found that the reactivity of these reactions is enhanced as the group 1 cations increase, and the regioselectivity is influenced by steric repulsion between the nucleophile and the substrate as well as the asymmetric orbital density on the epoxide. Overall, the concept of Pauli-lowering catalysis was once again demonstrated as a general phenomenon.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Zi-Yu Zhang, Jie Ren, Ming Zhang, Xiu-Fang Xu, Xiao-Chen Wang
Summary: This study reports the synthesis of N-heterocycles using borane-catalyzed dehydrogenative cyclization of 2-cyclopropyl-N,N-dimethylanilines. The key steps include borane-mediated cyclopropane ring-opening and borane-mediated hydride abstraction from the N-methyl group. The substituent at the cyclopropyl unit greatly influences the reaction pathway and determines the major reaction product.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Review
Chemistry, Applied
Anna Gulevskaya, Daria Tonkoglazova
Summary: Helicenes are polycyclic aromatic molecules with unique structures and properties. They have been widely applied in material science, nanoscience, and other fields. However, synthesizing helicenes remains a challenge, and alkyne cyclizations show great potential as a method. This review focuses on the development and applications of alkyne-based syntheses of carbo- and heterohelicenes.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Anton L. Shatsauskas, Ekaterina S. Keyn, Anton J. Stasyuk, Sergey A. Kirnosov, Vladislav Yu. Shuvalov, Anastasia S. Kostyuchenko, Alexander S. Fisyuk
Summary: A new approach for the synthesis of phenanthridin-4-ols and 4-hydroxyphenanthridin-6(5H)-one derivatives was developed. The AlCl3-mediated rearrangement of available 4-phenylbenzo[d]oxazoles and 4-phenyl-1,3-benzoxazol-2(3H)-one yielded the desired products with yields ranging from 43% to 89%. Quantum chemical calculations were utilized to describe the reaction mechanism and predict the thermodynamic parameters.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Multidisciplinary
Nayanthara Asok, Benjamen A. Zondag, Ekadashi Pradhan, Mary Odagwe, Jesse LeBlanc, Joshua C. Walsh, Graham J. Bodwell, Tao Zeng, Thomas Baumgartner
Summary: A series of luminescent, neutral pentacoordinate dithieno[3,2-b:2',3'-d]phosphole compounds was synthesized by [4+1] cycloaddition of o-quinones with the corresponding trivalent phospholes. This study comprehensively investigates various methods to systematically improve the Lewis acidity of neutral and stable main-group Lewis acids with practical value for a range of chemical transformations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Songyang Jin, Xinxin Geng, Yujun Li, Ke Zheng
Summary: In this study, an environmentally-friendly light-induced Minisci alkylation of N-heteroarenes using diphenyl phosphate as catalyst under metal- and photocatalyst-free conditions was reported. The use of radical precursor redox-active esters (RAEs) as alkylating reagents for the functionalization of N-heteroarene derivatives was demonstrated, with a focus on pyridine, quinoline, and isoquinoline. Mechanistic studies indicated that diphenyl phosphate played a key role through hydrogen bonding in the catalytic cycle.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Vachiraporn Ajavakom, Potchanee Pandokrak, Sofia S. Salim, Gamal A. I. Moustafa, Richard K. Bellingham, Joseph T. Hill-Cousins, Anawat Ajavakom, Richard C. D. Brown
Summary: A ring-closing metathesis (RCM) reaction of monobrominated dienes using Grubbs II catalyst was reported, giving moderate to good yields (40-80%) of seven-membered bromoolefins. Attempts to form five-, six-, or eight-membered bromoolefins through RCM were unsuccessful, except for one example that resulted in the formation of a bromomethyl-substituted cyclohexene as a byproduct. The selected bromoolefin RCM products showed utility in Suzuki-Miyaura reactions. Vinylic halide exchange (Br -> Cl) was observed as a side reaction under RCM conditions.
Review
Biochemistry & Molecular Biology
Krzysztof Nowicki, Piotr Pacholak, Sergiusz Lulinski
Summary: This review discusses the chemistry of organoboron heterocycles structurally related to benzoxaboroles, where a carbon atom in a boracycle or fused benzene ring is replaced by a heteroelement such as boron, silicon, tin, nitrogen, phosphorus, or iodine. It also describes ring expanded systems based on naphthalene and biphenyl cores. The information covers synthetic methodology, structural and physicochemical characteristics, as well as the potential applications of these heterocycles in organic synthesis and medicinal chemistry, focusing on their promising antimicrobial activity.
Review
Chemistry, Organic
Raffaella Bucci, Francesca Foschi, Camilla Loro, Emanuela Erba, Maria Luisa Gelmi, Sara Pellegrino
Summary: This review emphasizes the recent advances in the design and synthesis of cyclic turn mimics, focusing on their ability to induce gamma-, beta-, and alpha-turns in peptidomimetics.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Chemistry, Applied
Seoung-Mi Choi, Ju Hyun Kim
Summary: This review summarizes the progress made in the synthesis of 2H-pyrroles since 2000, including methods such as dearomatization of 1H-pyrrole, oxidation of pyrrolines or pyrrolidines, ring construction via catalytic cycloaddition, and rearrangement of 3H-pyrroles.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Jiru Shao, Caiyun An, Sunewang R. Wang
Summary: This study reports an easy method for synthesizing polysubstituted 2-pyrones from readily available 2-acylcyclopropane-1-aryl-1-carboxylates mediated by TfOH, with a key role played by the strongly donating 1-aryl group in directing the C-C bond cleavage of the donor-acceptor cyclopropane ring to form the 2-pyrone ring through lactonization.
SYNTHESIS-STUTTGART
(2021)
Review
Chemistry, Multidisciplinary
Rajarshi Mondal, Mohamed Agbaria, Zackaria Nairoukh
Summary: This article discusses the impact of fluorine substitution on the relative orientation of C-F bonds in organic molecules, as well as the conformational behavior and stability of fluorinated aliphatic carbo- and heterocyclic systems. The contribution of charge-dipole, dipole-dipole, and hyperconjugative interactions to the stability of fluorinated alicyclic systems is detailed, alongside the presentation of the most recent applications.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Review
Virology
Sibasish Manna, Koushik Das, Sougata Santra, Emily V. Nosova, Grigory V. Zyryanov, Sandipan Halder
Summary: This review article identifies and discusses the antiviral properties of different oxa- and aza-heterocycles, correlating them with their structural features. The primary objective is to explore the potential of these ring systems as antiviral agents, as well as their synthesis routes and biological significance. The structure-activity relationship (SAR) of the heterocyclic compounds and their important characteristics are presented, providing a suitable platform for medicinal chemists and biotechnologists. The synergistic conclusions are crucial for future drug discovery programs.
