Article
Biochemistry & Molecular Biology
Laura Legnani, Salvatore Giofre, Daniela Iannazzo, Consuelo Celesti, Lucia Veltri, Maria Assunta Chiacchio
Summary: In this paper, a computational mechanistic study of RuO4-catalyzed oxidation of isoxazolidines was conducted, focusing on the endo/exo oxidation selectivity. The modeling results were nicely confirmed by experimental data.
Article
Chemistry, Multidisciplinary
Sebastian Heindl, Margaux Riomet, Jan Matyasovsky, Miran Lemmerer, Nicolas Malzer, Nuno Maulide
Summary: A chemoselective and robust protocol for the gamma-oxidation of beta,gamma-unsaturated amides has been developed, showcasing the synthetic utility of the products obtained through radical cyclisation reactions and oxidation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Inorganic & Nuclear
Marek Steklac, Martin Breza
Summary: In this study, the structures and electron structures of a series of [MCl4](q) complexes of first-row transition metals were optimized, showing that the physical oxidation states and calculated d-electron populations increase with the negative charge q. Additionally, transition metal complexes with 'innocent' ligands can be used to estimate the physical oxidation states of analogous complexes with 'non-innocent' ligands.
Article
Chemistry, Multidisciplinary
Jean-Marc I. A. Lawrence, Paul E. Floreancig
Summary: This work presents a method for electrochemical oxoammonium ion regeneration by understanding the relationship between intermediate cation stability and reaction kinetics, which can expand the scope of electrocatalysis.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Martin Tomanik, Zhi Xu, Seth B. Herzon
Summary: This article describes an enantioselective total synthesis of the nonahydroxylated sesquiterpenoid euonyminol, which is the dihydro-flagarofuran nucleus of the macrocyclic terpenoid alkaloids known as the cathedulins. Key features of the synthetic sequence include highly diastereoselective reactions to establish key structural elements, ultimately providing the first synthetic access to enantioenriched euonyminol and establishing a platform for synthesizing the cathedulins.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Robert Obertik, Josef Chudoba, Jiri Sturala, Jan Tarabek, Lucie Ludvikova, Tomas Slanina, Burkhard Koenig, Radek Cibulka
Summary: Catalyst recovery is crucial in photoredox catalysis, and conventional methods using sacrificial agents may cause side reactions. This study presents a new approach using acetonitrile as both an electron acceptor for catalyst recovery and a solvent in anaerobic conditions. The unique properties of the catalyst, 7,8-dimethoxy-3-methyl-5-phenyl-5-deazaflavinium chloride, allow for efficient chemoselective photooxidation reactions. Mechanistic studies reveal that the electron release from an excited deazaflavin radical to acetonitrile is essential for catalyst recovery.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Grace M. Ibsen, Vitor Menezes H. da Silva, J. Cole Pettigrew, Sharon R. Neufeldt
Summary: In the absence of strong ancillary ligands, palladium salts selectively cleave C-OTf in the room-temperature Suzuki couplings of chloroaryl triflates in acetonitrile. Ligand-free conditions in DMSO also promote triflate-selective Suzuki coupling of bromoaryl triflates. DFT calculations and experimental evidence suggest the triflate-selective oxidative addition takes place at homogeneous, possibly mononuclear, anionic palladium supported by a solvent molecule.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Physical
Jie Qi Ng, Hiro Arima, Takuya Mochizuki, Kohei Toh, Kai Matsui, Manussada Ratanasak, Jun-Ya Hasegawa, Manabu Hatano, Kazuaki Ishihara
Summary: A highly chemoselective transesterification catalyzed by NaOAr or Mg(OAr)2 was developed, allowing for the production of functionalized acrylates without undesired Michael additions under mild reaction conditions. Computational density functional theory calculations supported the high chemoselectivity of this reaction.
Article
Chemistry, Physical
Ting-Ting Yang, Min Zhang, Qiao-Yu Zhang, Congcong Wang, Li-Hui Chen, Donghui Wei
Summary: The mechanisms of transformations of biphosphirane-M(CO)5 (M = Mo, Cr) complexes were studied through a combined DFT and experimental approach. Three possible pathways were identified, with both stepwise pathways being energetically more favorable than the concerted pathway. The electrophilicity of the active intermediates was studied, showing that the phosphorus atoms can act as electrophilic sites.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2021)
Article
Chemistry, Applied
Asit Kumar Das, Sneha Nandy, Sanjay Bhar
Summary: An economically efficient and operationally simple ligand-free protocol has been developed for the chemoselective oxidation of benzylic alcohols to carbonyl compounds using alumina-supported nickel nanoparticles. The protocol demonstrates excellent chemoselectivity and tolerance towards various sensitive moieties, with the catalyst being recyclable without significant loss in activity. The heterogeneous nature of the catalyst has been established, making it a promising eco-friendly option for oxidation reactions.
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Mike Ong, Marlene Arnold, Alexander W. Walz, Johannes M. Wahl
Summary: Amino diphenylphosphinates can undergo ring expansion of cyclobutanones to gamma-lactams under mild conditions, achieving a reaction pathway different from the common Beckmann reaction due to the ambivalent character of the aminating agent. The method exhibits high regioselectivity, stereospecificity, and chemoselectivity, making it suitable for late-stage skeletal editing.
Article
Chemistry, Organic
He Zhang, Meng-Chan Sun, Li-Ming Yin, Donghui Wei, Mao-Ping Song, Dandan Yang, Jun-Long Niu
Summary: This study presents an efficient metal-free intramolecular C(sp(3))-H bond sulfonamidation reaction, offering a new synthetic approach to 5-membered cyclic sulfonamides. The reaction mechanism involves proton transfer coupled with the S(N)2 (PTS(N)2) process, distinguishing it from other pathways.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Applied
Tao Zhang, Yanhong Wang, Bin Wang, Weiwei Jin, Yu Xia, Chenjiang Liu, Yonghong Zhang
Summary: This paper describes a visible-light-induced chemical reaction that can synthesize structurally diverse lactams under mild and transition metal-free conditions. The utility of this method is showcased through gram-scale synthesis and deprotection.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Review
Chemistry, Applied
Nuno G. Alves, Americo J. S. Alves, Maria I. L. Soares, Teresa M. V. D. Pinho e Meloa
Summary: Spirocyclic molecules, especially the spiro-lactams subclass, are highly valued for their complex three-dimensional features and structural rigidity, making them extensively explored for their bioactivity and utility in various scientific fields such as drug design and organic synthesis. Efforts have been made towards developing new synthetic strategies for spirocyclic lactams due to their broad potential, with significant advancements reported since 2015 in the synthesis of spiro-beta-lactams and spiro-delta-lactams.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Medicinal
Yusuke Sasano, Aoto Yamaichi, Ryota Sasaki, Shota Nagasawa, Yoshiharu Iwabuchi
Summary: Four distinctive sets of optimal nitroxyl radical/copper salt/additive catalyst combinations have been identified for aerobic oxidation of various primary alcohols to their corresponding aldehydes. Less nucleophilic catalysts showed higher catalytic activities for oxidation of specific primary allylic and propargylic alcohols. The identified optimum conditions successfully oxidized various primary alcohols, including unprotected amino alcohols and divalent-sulfur-containing alcohols.
CHEMICAL & PHARMACEUTICAL BULLETIN
(2021)
Article
Polymer Science
Lucia D'Accolti, Alessia De Cataldo, Francesco Montagna, Carola Esposito Corcione, Alfonso Maffezzoli
Summary: This study presents a new method using recyclable 3D-printed polylactic acid (PLA) scaffolds coated with iron oxide catalyst for Fenton reactions on aromatic model molecules. The results show that the scaffolds have advantages of easier handling and waste reduction, leading to a reduction in times and costs. The catalyst coating has limited leachability and can be easily recovered and reused multiple times.
Article
Chemistry, Multidisciplinary
Federico Begato, Roberto Penasa, Klaus Wurst, Giulia Licini, Cristiano Zonta
Summary: Dynamic covalent chemistry (DCC) has been valuable for synthesizing increasingly complex molecular architectures. In this study, we utilized imine DCC chemistry to prepare TPMA-based supramolecular cages for molecular recognition applications. However, the hydrolytic lability of imines limits some applications. We introduced a synthetic strategy that combines the advantages of imine chemistry with the ability to synthesize chiral hydrolytically stable structures through a [3,3]-sigmatropic rearrangement.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Giovanni Lonardi, Riccardo Parolin, Giulia Licini, Manuel Orlandi
Summary: Enantioselective reduction reactions are important transformations for constructing trisubstituted stereogenic centers. Among these reactions, the asymmetric conjugate reduction (ACR) of alpha,beta-unsaturated compounds has become a convenient approach for synthesizing chiral compounds. This review provides a comprehensive collection of catalytic ACR methods involving transition-metal, organic, and enzymatic catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Inorganic & Nuclear
Carla Sappino, Stefano Di Stefano, Osvaldo Lanzalunga, Cristiano Zonta, Giulia Licini
Summary: This article describes two different classes of multidentate ligands (aminotriphenolate and dipyridinimine) and their corresponding metal (Ti, V, Mo, W, Fe) complexes. These catalysts efficiently activate the environmentally friendly oxidant H2O2, promoting a wide range of oxidative processes (sulfoxidations, N-oxidations, epoxidations, haloperoxidation, alcohol oxidation, hydroxylation).
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Giacomo Pugliese, Francesco Vaghi, Giovanni Lonardi, Giulia Licini, Manuel Orlandi
Summary: Co-Salox complexes are efficient catalysts for reducing prochiral alpha,beta-unsaturated esters. They can be easily prepared from inexpensive materials, offering a viable alternative to previously reported Co-catalysts. The presence of NaBH4 and EtOH in the reaction leads to the stereoselective formation of chiral esters, amides, and nitriles with high yields and enantioselectivities. The reactivity and enantioselectivity are influenced by the concentration of the reductant counter cation (Na+) and the polarity of the solvent, suggesting a complex mechanistic pathway.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Graziana Difonzo, Marica Troilo, Michele Casiello, Lucia D'Accolti, Francesco Caponio
Summary: Agronomic practices and winemaking processes generate a significant amount of waste and by-products, which are usually seen as environmentally unsustainable. However, vine shoots and grape stalks can be reused to obtain xylo-oligosaccharides and polyphenols. This study examined three different autohydrolysis treatments using water, water:ethanol, and water:Amberlyst to extract enriched extracts. Ethanol enhanced the extraction of xylan-class compounds, especially in vine shoot samples, while grape stalks showed increased antioxidant activity (128.04 and 425.66 mu mol TE/g for ABTS and DPPH) and total phenol content (90.92 mg GAE/g).
Article
Polymer Science
Onofrio Losito, Michele Casiello, Caterina Fusco, Helena Mateos Cuadrado, Antonio Monopoli, Angelo Nacci, Lucia D'Accolti
Summary: The total amount of cellulose waste produced in the EU every year, including paper, wood, food, and other human activity waste, is about 900 million tons per year. This waste represents a significant opportunity to produce renewable chemicals and energy. This paper presents a novel approach to utilize various urban wastes such as cigarette butts, sanitary pant diapers, newspapers, and soybean peels as sources of cellulose to produce valuable industrial intermediates.
Review
Chemistry, Multidisciplinary
Federico Begato, Giulia Licini, Cristiano Zonta
Summary: Spatial organization using confinement has been extensively studied in the field of supramolecular chemistry, with applications in sensing, catalysis, and delivery continuously emerging. This minireview focuses on the applications of chiral supramolecular cages (CSC) in catalysis, sensing, and chiroptical properties. The review discusses the preparation strategies for chiral supramolecular cages, including both purely organic architectures and those prepared using metal-ligand coordination bonds. Recent findings on the applications of CSC, particularly in stereodynamic systems, are presented to highlight the current scientific interests and future opportunities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Federico Begato, Giulia Licini, Cristiano Zonta
Summary: Taking inspiration from Nature, supramolecular chemistry has developed novel systems that can change their structure under specific stimuli, and among them, supramolecular cages have been investigated for controlled guest release. This paper presents a novel methodology using phenanthrenequinone to selectively change the binding properties of a tris(2-pyridylmethyl)amine-based cage. Subcomponent substitution is used to control the inclusion ratio of competing guests with different sizes or chirality.
Article
Chemistry, Multidisciplinary
Roberto Penasa, Federico Begato, Giulia Licini, Klaus Wurst, Sergio Abbate, Giovanna Longhi, Cristiano Zonta
Summary: The use of chiroptical techniques in chiral sensing is gaining popularity. Circular dichroism (CD) is commonly used, but vibrational CD (VCD), circularly polarized luminescence (CPL), and Raman optical activity (ROA) are emerging as innovative tools. This study reports the use of an anthracene-decorated tris(2-pyridylmethyl)amine zinc complex (TPMA) as a chiral sensor, using either CD or fluorescence detected circular dichroism (FDCD). The FDCD technique allows for determination of enantiomeric excess at low sensor concentrations. The limitations and possibilities of this methodology, particularly regarding probe specificity in the presence of contaminants, are discussed.
CHEMICAL COMMUNICATIONS
(2023)
