Article
Chemistry, Organic
Pham Duy Quang Dao, Chan Sik Cho
Summary: A class of trinuclear N-fused hybrid scaffolds, benzo[4,5]imidazo[1,2-a]benzo[4,5]imidazo[1,2-c]quinazolines and -pyrimidines, were successfully synthesized in good yields using a microwave-assisted coupling and cyclization process with 2-(2-Bromoaryl)- and 2-(2-bromovinyl)benzimidazoles as building blocks. The reaction is believed to proceed through an initial C(sp(2))-N coupling followed by a nucleophilic aromatic substitution (SNAr) and cyclization, resulting in the extrusion of alcohols.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Karolina Dzedulionyte, Melita Veiksaite, Vit Moravek, Vida Malinauskiene, Greta Rackauskiene, Algirdas Sackus, Asta Zukauskaite, Egle Arbaciauskiene
Summary: A general approach for the synthesis of tetrahydro-4H-pyrazolo[1,5-a][1,4]diazepin-4-one derivatives was developed. This approach involved a regioselective strategy for synthesizing ethyl 1-(oxiran-2-ylmethyl)-1H-pyrazole-5-carboxylates followed by ring-opening and cyclisation reactions to yield the target compounds. A straightforward two-step method was also applied to functionalize other derivatives. The structures of the fused heterocyclic compounds were confirmed using spectroscopy techniques.
Article
Chemistry, Applied
Alexander Garay-Talero, Paola Acosta-Guzman, Diego Gamba-Sanchez
Summary: This manuscript presents a regioselective chlorination of arenes, yielding almost exclusively the monochlorinated product. It tolerates a wide range of functional groups and substituted aromatic rings, and demonstrates the utilization of chlorosulfonium salts as the chlorinating agent, avoiding the formation of organic byproducts.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Review
Chemistry, Inorganic & Nuclear
Olaya Bernardo, Silvia Gonzalez-Pelayo, Luis A. Lopez
Summary: The marriage of heterocyclic compounds with ferrocene has been a fruitful field of research, with several ferrocene-embedded heterocyclic compounds reported in recent years. The synergistic combination of properties from both heterocyclic and metallacyclic motifs in fused systems has led to interesting applications, particularly in asymmetric catalysis.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Marcelo M. de Siqueira, Pedro P. de Castro, Juliana A. dos Santos, Leona S. Flores, Walysson F. de Paiva, Sergio A. Fernandes, Giovanni W. Amarante
Summary: A metal-free method for the aza-Michael reaction between isoxazol-5-ones and enones was developed, providing a wide range of products in moderate to excellent yields under mild conditions. The isoxazol-5-ones selectively reacted at the nitrogen atom, without attacking the carbon atom at the 4-position. Two readily available Bronsted acids, hydrochloric acid and p-sulfonic acid calix[4]arene, were investigated as catalysts, with hydrochloric acid showing slightly higher yields when using dibenzylideneacetones as Michael acceptors. p-sulfonic acid calix[4]arene achieved better yields when using chalcones as Michael acceptors, and could be recovered and reused without significant loss of performance.
REACTION CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Liping Ye, Qian Miao
Summary: New molecular scaffolds with C-, Z-, and box-shaped configurations were synthesized by combining phenazine and pyrene units with oxanorbornene. X-ray crystallography revealed that the C-shaped molecules showed two unique π-π stacking modes of phenazine depending on substituent groups, while the box-shaped molecule formed hydrogen bonds with four chloroform molecules and accommodated two more chloroform molecules in the cavity. The pair of diastereomeric C- and Z-shaped molecules exhibited similar charge transfer absorption and emission, indicating that the intramolecular charge transfer between pyrene (p-donor) and phenazine (p-acceptor) was not affected by the overall molecular geometry.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Madhawee K. Arachchi, Richard N. Schaugaard, H. Bernhard Schlegel, Hien M. Nguyen
Summary: Asymmetric reactions that convert racemic mixtures into enantioenriched amines, especially those with a tetrasubstituted carbon stereocenter, are of great importance in pharmaceutical research. In this study, a chiral diene-ligated rhodium-catalyzed asymmetric substitution reaction was developed to efficiently prepare α-trisubstituted-α-tertiary amines containing pharmaceutically relevant secondary amine cores.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Madhawee K. Arachchi, Richard N. Schaugaard, H. Bernhard Schlegel, Hien M. Nguyen
Summary: The asymmetric synthesis of α-trisubstituted-α-tertiary amines is of significant importance in the pharmaceutical industry. In this study, a chiral diene-ligated rhodium-catalyzed asymmetric substitution reaction was developed, leading to efficient synthesis with high yields and excellent selectivities.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Scott T. Shreiber, Albert Granados, Bianca Matsuo, Jadab Majhi, Mark W. Campbell, Shivani Patel, Gary A. Molander
Summary: This study describes an aryl disulfide mediated C-F bond activation method to generate valuable gem-difluoroalky-lindoles. It is the first transition-metal-free redox-neutral C-F bond activation strategy and utilizes readily available commodity reagents under mild reaction conditions. The reaction allows for the use of various substituted indoles and alpha-fluoro-substituted esters. Additionally, this C-F activation method also enables the activation of trifluoromethylated arenes for the preparation of bis-benzylic gem-difluoromethylenes between indole and arene substructures, providing access to a unique chemical space.
Article
Chemistry, Organic
Saravanan Gowrisankar, Bastian Bernhardt, Jonathan Becker, Peter R. Schreiner
Summary: New meta-substituted tetraaryl adamantane derivatives were synthesized in one step through Friedel-Crafts adamantylation using AlCl3 and t-butyl bromide. These products exhibit improved highly directional white-light emission compared to tetraphenyl adamantane upon irradiation with a continuous wave laser diode.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Jinhang Yu, Mengjiao Xu, Xinyuan Wang, Bei Zhang, Hui Mao, Xin Lv, Liejin Zhou
Summary: A novel catalyst-controlled reaction is reported, which allows for the rapid and efficient synthesis of a series of bicyclic compounds by using readily available acyclic enyne-amides and crotonate-derived sulfur ylides as substrates.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Hironobu Nakazawa, Yuta Uetake, Yumi Yakiyama, Hidehiro Sakurai
Summary: 2,3,5,6,8,9-Hexakis(bromomethyl)sumanene, a hexa-substituted sumanene with bromomethyl groups at the peripheral aromatic carbons, was synthesized with a one-step reaction in 97% yield. Single-crystal X-ray structural analysis revealed the formation of a dimer structure. Nucleophilic substitution introduced multiple substituents and the UV-vis absorption and emission spectra demonstrated a clear redshift compared to pristine sumanene, indicating extended conjugation in hexa-substituted sumanenes.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Luis R. Domingo, Maria Jose Aurell, Mar Rios-Gutierrez
Summary: The reaction between N-phenyl iminoborane and benzaldehyde, presented by Liu et al., was investigated using Molecular Electron Density Theory (MEDT). The formation of a fused aromatic compound involves three consecutive reactions: the formation of a weak molecular complex between the reactants, an intramolecular electrophilic attack of the activated carbonyl carbon, and a formal 1,3-hydrogen shift. This domino reaction shows similarities to the Bronsted acid catalyzed Povarov reaction.
Article
Chemistry, Applied
Surajit Duari, Subrata Biswas, Arnab Roy, Srabani Maity, Abhishek Kumar Mishra, Aguinaldo R. Souza, Asma M. Elsharif, Nelson H. Morgon, Srijit Biswas
Summary: In this study, a catalytic synthetic strategy was developed to access various N-functionalized heterocyclic derivatives. The reaction involves the direct nucleophilic substitution of alcohols followed by X to N alkyl group migration. Methyl trifluoromethanesulfonate was found to be an efficient catalyst for this reaction. The mechanism was elucidated through experiments and DFT calculations.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Inorganic & Nuclear
[Anonymous]
Summary: This article reviews the recent advances in the synthesis and applications of ferrocene-fused nitrogen heterocycles. The transfer of powerful transition-metal-catalyzed methodologies for C-H bond functionalization of benzene derivatives to ferrocene has played a significant role in this field.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Gabriele Lupidi, Alessandro Palmieri, Marino Petrini
Summary: A novel riboflavin-promoted reaction of primary nitroalkanes coupled with a nitroaldol reaction was discovered, enabling the synthesis of functionalized nitro alcohols under mild reaction conditions. However, secondary nitroalkanes were consumed under the reaction conditions without yielding the expected nitroaldol products.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Elena Chiurchiu, Susanna Sampaolesi, Pietro Allegrini, Daniele Ciceri, Roberto Ballini, Alessandro Palmieri
Summary: This study presents the first continuous flow chemical synthesis of cannabidiol (CBD) and its analogues, achieving high yields and limiting the formation of psychoactive and illegal cannabinoids.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Applied
Ivano Maule, Gabriele Razzetti, Alessandro Restelli, Alessandro Palmieri, Cinzia Colombo, Roberto Ballini
Summary: The thermal stability of a set of aliphatic nitroalkanes was tested by DSC analysis, showing similar exothermic decomposition phenomenon for all compounds. Recommendations for avoiding decomposition were provided based on the estimated maximum process temperature.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2021)
Review
Chemistry, Applied
Gabriele Lupidi, Alessandro Palmieri, Marino Petrini
Summary: N-Activated ketimines are characterized by electron-withdrawing groups linked to the nitrogen atom, enhancing the electrophilic character and allowing addition reactions with weak nucleophiles. The presence of oxygen atoms in these groups is crucial for asymmetric catalytic reactions. This review summarizes the literature on the synthesis of optically active alpha-substituted amino derivatives using open-chain N-activated ketimines.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Physical
Carlotta Raviola, Cristina Carrera, Massimo Serra, Alessandro Palmieri, Gabriele Lupidi, Giovanni Maestri, Stefano Protti
Summary: The photoreactivity of (E)-beta-nitroenones involves competitive pathways of stereoisomerisation to (E)-beta-nitroenones and deconjugation to beta-nitro-beta,gamma-enones, both originating from the triplet excited state of the starting substrates.
Article
Chemistry, Organic
Benedetta Bassetti, Roberto Ballini, Daniele Ciceri, Pietro Allegrini, Alessandro Palmieri
Summary: This study reports a new practical and efficient preparation method for the flavonoid luteoloside with an excellent overall yield of 40% via a four-step synthetic approach.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Applied
Alexandra Jorea, Benedetta Bassetti, Klaus Gervasoni, Stefano Protti, Alessandro Palmieri, Davide Ravelli
Summary: The hydroalkylation of nitroalkenes and beta-nitroacrylates has been optimized using a photocatalytic strategy. The decatungstate anion has been utilized as a versatile photocatalyst for the generation of alkyl radicals from various substrates, such as aliphatic heterocycles, amides, and cycloalkanes.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Plant Sciences
Eleonora Spinozzi, Marta Ferrati, Cecilia Baldassarri, Filippo Maggi, Roman Pavela, Giovanni Benelli, Cristina Aguzzi, Laura Zeppa, Loredana Cappellacci, Alessandro Palmieri, Riccardo Petrelli
Summary: Compoundsisolated from botanical sources, like carlina oxide, show great potential as bioinsecticides that can effectively target various arthropod vectors and agricultural pests while posing moderate toxicity to non-target species. In this study, the chemical synthesis of carlina oxide analogues was developed and their insecticidal activity, as well as cytotoxicity, were evaluated. The analogues showed comparable effectiveness to purified carlina oxide against houseflies and a significantly higher efficacy than carlina oxide on Culex quinquefasciatus, with a better safety profile on human keratinocyte cells. Overall, this study paves the way for the production of nature-inspired insecticides.
JOURNAL OF NATURAL PRODUCTS
(2023)
Review
Chemistry, Applied
Alessandro Palmieri, Marino Petrini
Summary: The limited nucleophilic character and bidentate nature of unactivated nitroalkane anions make alkylation and allylation procedures troublesome. This review summarizes the most rewarding approaches, mainly based on metal-catalyzed processes involving purely ionic or mixed ionic-radical intermediates, that have been devised to overcome this limitation.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Review
Chemistry, Organic
Roberto Ballini, Alessandro Palmieri, Marino Petrini
Summary: This review provides a journey of the catalyst usage for enantioselective conjugate addition of nitroalkanes to electron-poor alkenes. Chiral organocatalytic methods and chiral metal-ligand complexes are commonly used catalytic systems. The obtained adducts can easily convert the nitro group into a primary amine for the preparation of nitrogen-containing compounds.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Gabriele Lupidi, Alessandro Palmieri, Marino Petrini
Summary: Functionalized quinoxalines can be prepared with a fast and high-yielding protocol using choline chloride/water NADES at room temperature without additional activation. The products obtained do not require further purification.
