Article
Chemistry, Multidisciplinary
Melina Knezevic, Konrad Tiefenbacher
Summary: We report the synthesis and application of four new supramolecular tweezer-based oxidation catalysts, which consist of the well-explored M(pdp/mcp) oxidation moiety and a molecular tweezer capable of binding ammonium salts. All catalysts display preferential oxidation of the strongly deactivated C3/C4 positions, to different degrees. Furthermore, the best performing catalyst Fe(pdp)Twe was explored with an expanded substrate scope, demonstrating that the deactivated positions C3/C4 are also preferentially oxidized in these cases.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Miquel Costas
Summary: The selective oxidation of aliphatic C-H bonds is still an unsolved problem in organic synthesis, but complexes with linear tetraazadentate ligands have proven to be structurally versatile and instrumental in designing new C-H oxidation reactions.
Article
Nanoscience & Nanotechnology
Yesim Sahin, Abel T. Sika-Nartey, Kerem E. Ercan, Yusuf Kocak, Sinem Senol, Emrah Ozensoy, Yunus E. Turkmen
Summary: This article describes the development of a new aerobic C-H oxidation methodology catalyzed by a precious metal-free LaMnO3 perovskite catalyst. Molecular oxygen is used as the sole oxidant, showcasing high efficiency. Systematically optimizing the electronic and structural properties of the LaMnO3 catalysts, along with the essential reductive pretreatment protocol, led to the high catalytic activities observed.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Jinyang Wu, Youran Luo, Lingxuan Chen, Xuan Sun, Xinnan Chen, Song Qin, Wen Feng, Xiaowei Li, Lihua Yuan
Summary: Host-guest complexation using hydrogen-bonded macrocycles facilitates the activation of the Bobbitt oxidant reagent for efficient oxidation of unactivated primary alcohols. This work presents a complementary approach in supramolecular catalysis, employing shape-persistent macrocycles for the activation of Bobbitt's salt.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Isaac Choi, Zhigao Shen, Emanuel Ronge, Volker Karius, Christian Jooss, Lutz Ackermann
Summary: A recyclable hybrid manganese catalyst has been developed for site-selective azine C-H activation with weak amide assistance. The catalyst enables C3-H arylation and C3-H alkylation reactions, and has been characterized using detailed transmission electron microscopy analysis.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Jonathan Trouve, Purushothaman Rajeshwaran, Michele Tomasini, Antoine Perennes, Thierry Roisnel, Albert Poater, Rafael Gramage-Doria
Summary: Selective C-H bond borylation of challenging pyridines and imidazoles can be achieved in very short reaction times using a supramolecular approach. The catalyst used has a highly rigid zinc-porphyrin substrate-recognition site and a triazolopyridine chelating fragment attached to iridium. The selectivity of the borylation reaction is determined by the distance between the active site and the molecular recognition site, and is independent of the coordinating fragment to iridium. The understanding of the catalyst deactivation pathways led to the identification of a supramolecular catalyst that bypasses these pathways and provides a suitable balance of steric and electronic effects.
Article
Chemistry, Multidisciplinary
Kentaro Harada, Ryo Sekiya, Takeharu Haino
Summary: By utilizing a confined space, we have achieved the formation of trimeric structures composed of acetic acid and tartaric acid derivatives, with transfer and enrichment of chirality. The generated capsule guides the dynamic axial chirality and enables the emission of circularly polarized luminescence in the NIR region.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Courtney Ngai, Hoi-Ting Wu, Bryce Camara, Christopher G. Williams, Leonard J. Mueller, Ryan R. Julian, Richard J. Hooley
Summary: A self-assembled cage structure was synthesized by controlling the self-assembly of internal amines. Despite carrying a positive charge, the structure can extract protons from water in solution. The internal amines have lower basicity compared to their counterparts in free solution. This moderation is a hallmark of enzymatic catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Sabari Ghosh, Phuong Nguyen Tran, Dan McElheny, Juan J. Perez, Andy Nguyen
Summary: Metalloenzymes have achieved precise arrangements of secondary sphere non-covalent interactions through the iterative process of evolution. However, synthesizing scaffolds that display complex secondary sphere elements in abiotic systems can be challenging and time-consuming. To overcome this, researchers have developed a highly modular and rapid synthetic strategy using solid-phase peptide synthesis and non-canonical residues to construct a ligand platform with multiple, diverse functional groups in the secondary coordination sphere.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
B. Hua, L. O. Alimi, G. Zhang, Y. Ding, B. Moosa, W. S. Baslyman, N. M. Khashab
Summary: This study investigates the use of methylene-bridged trianglamines as supramolecular adsorbents for the selective separation of linear alkane isomers. The selectivity is attributed to the host-guest complexation resulting from the size matching between the trianglamines cavity and the linear guest molecules. Moreover, the supramolecular adsorbents exhibit high recyclability and almost no loss of efficiency, showing great promise for industrial applications.
MATERIALS TODAY CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Yaohang Cheng, Yuhang He, Jie Zheng, Hui Yang, Jun Liu, Guanghui An, Guangming Li
Summary: The method developed utilizes Ru(II) catalysis to facilitate the synthesis of challenging difluoroalkylated aldehydes and ketones with para-selectivity.
CHINESE CHEMICAL LETTERS
(2021)
Review
Chemistry, Multidisciplinary
Catriona C. James, Bas de Bruin, Joost N. H. Reek
Summary: The importance of transition metal catalysis lies in its wide range of applications, including the synthesis of chemicals, natural products, and pharmaceuticals. However, a relatively new application is the catalysis of new-to-nature reactions inside living cells. The complex environment of living cells poses challenges to transition metal catalysts due to the potential inhibition or deactivation by various biological components. In this review, we summarize the current progress in the field of transition metal catalysis, focusing on the evaluation of catalysis efficiency under living cell and biological conditions. Catalyst poisoning is a common issue in this field, and we suggest that future research should explore physical and kinetic protection strategies to enhance the reactivity of catalysts in cells.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Chiara F. M. Mirabella, Gemma Aragay, Pablo Ballester
Summary: We report the self-assembly of shape-persistent [1 + 1] tetra-imine cages 1 based on two different tetra-alpha aryl-extended calix[4]pyrrole scaffolds in chlorinated solvents and in a 9 : 1 CDCl3 : CD3CN solvent mixture. The use of a bis-N-oxide 4 as template has a positive effect on the reaction yield. The binding properties of the self-assembled tetra-imine cages 1 with pyridine N-oxide derivatives were investigated using H-1 NMR spectroscopy.
Article
Chemistry, Multidisciplinary
Nikki A. Tzioumis, Duncan A. Cullen, Katrina A. Jolliffe, Nicholas G. White
Summary: A simple biphenyl bis-amidinium compound (1.Cl-2) can selectively precipitate sulfate from water even at low concentrations. It shows complete selectivity against monovalent anions and high selectivity even against CO32- and HPO42-. It is highly effective in removing sulfate (>90%) from both seawater and highly acidic conditions relevant to mining waste-streams. X-ray crystallography reveals the structure of 1.SO4 with tightly packed, anhydrous arrangement where each sulfate anion receives eight hydrogen bonds from amidinium N-H hydrogen bond donors.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Lu Yang, Xiaoxue Huang, Suna Wang, Daopeng Zhang, Zhen Zhou
Summary: Supramolecular chemistry has become an interdisciplinary discipline which includes chemistry, physics, and biology. Metal-organic molecular containers (MOMCs) have received considerable attention due to their rich chemical properties and wide potential applications. In this paper, selected examples of coordination-driven metal-organic supramolecular systems are reviewed, focusing on self-assembly construction and various applications. The different choice of organic ligands with flexible backbones during construction leads to diverse configurations compared to rigid ligands, providing a different perspective on metal-organic system construction.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Laia Vicens, Giorgio Olivo, Miquel Costas
Summary: This study presents a supramolecular strategy for enzyme-like H2O2 activation at a biologically inspired manganese catalyst, allowing for catalytic asymmetric epoxidation. Modulation of both amino acid and catalyst structure can tune the efficiency and enantioselectivity of the reaction, and an investigation on the oxidative degradation pathway of the system is provided.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Inorganic & Nuclear
Miquel Costas, Anna Company
Summary: Replacement of C-H by C-F bonds provides lipophilicity and chemical stability to organic molecules, making organofluorides interesting compounds in various fields. However, the environmental persistence due to the same properties leads to a search for biological and chemical reagents that could cleave the C-F bonds. This review discusses oxidative enzymes and coordination complexes as potential solutions for the development of novel catalytic methodologies.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Marco Galeotti, Laia Vicens, Michela Salamone, Miquel Costas, Massimo Bietti
Summary: The C(sp(3))-H bond oxygenation of cyclopropane-containing mechanistic probes has been studied using hydrogen peroxide catalyzed by manganese complexes. The study showed the presence of both unrearranged and rearranged oxygenation products, suggesting the involvement of cationic intermediates and different pathways. The selective formation of either unrearranged or rearranged product in high yield can be achieved by choosing appropriate catalyst structure and reaction conditions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Arnau Call, Marco Cianfanelli, Pau Besalu-Sala, Giorgio Olivo, Andrea Palone, Laia Vicens, Xavi Ribas, Josep M. Luis, Massimo Bietti, Miquel Costas
Summary: Reactions that allow selective functionalization of strong aliphatic C-H bonds have the potential to increase molecular complexity and expand chemical space. This study describes the catalytic site- and stereoselective gamma-lactonization of unactivated primary C-H bonds in carboxylic acid substrates using a chiral Mn catalyst. The reaction exhibits high site-selectivity and enables the oxidation of weaker secondary and tertiary C-H bonds. By manipulating the chirality of the catalyst, the reaction can achieve high diastereoselectivity in the lactonization of methyl groups in rigid cyclic and bicyclic carboxylic acids. The mechanistic analysis suggests that the reaction proceeds through a rebound type mechanism initiated by intramolecular 1,7-HAT.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Johann B. B. Kasper, Pattama Saisaha, Maurits de Roo, Mitchell J. J. Groen, Laia Vicens, Margarida Borrell, Johannes W. W. de Boer, Ronald Hage, Miquel Costas, Wesley R. R. Browne
Summary: This study elucidates the mechanism and reactive species involved in the oxidation of alkenes and alcohols with H2O2 under the presence of a specific catalyst. The findings suggest that a certain reactive species can engage in both alkene and alcohol oxidation reactions, exhibiting selectivity.
Article
Chemistry, Inorganic & Nuclear
Mainak Mitra, Alexander Brinkmeier, Yong Li, Margarida Borrell, Arnau Call, Julio Lloret Fillol, Michael G. Richmond, Miquel Costas, Ebbe Nordlander
Summary: Two new tetradentate N4 ligands and their corresponding Fe(II) complexes have been synthesized and characterized. The complexes exhibit excellent catalytic activity in the hydroxylation of alkanes and the oxidation of cyclooctene, using hydrogen peroxide as oxidant. Isotope labeling experiments provide insight into the steric influence exerted by the ligands on the relative reactivity of the oxo ligands.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Physical
Arnau Vicens, Laia Vicens, Giorgio Olivo, Osvaldo Lanzalunga, Stefano Di Stefano, Miquel Costas
Summary: Site-selective oxidation of aliphatic C-H bonds is achieved using a manganese oxidation catalyst equipped with two 18-benzo-6-crown ether receptors. The catalyst shows excellent selectivity towards the central methylenic sites of the long chain tetradecane-1,14-diamine. This selective oxidation overcomes challenges associated with differentiating between similar sites in organic molecules.
FARADAY DISCUSSIONS
(2023)
Article
Chemistry, Organic
Marika Di Berto Mancini, Marianna Bernardini, Beniamin Emanuel Birzu, Arianna De Santis, Stefano Di Stefano, Federico Frateloreto, Daria Khaksar, Andrea Lapi, Giorgio Olivo, Osvaldo Lanzalunga
Summary: The chemoselectivity of S-oxidation and hydrogen atom transfer (HAT) from C-H bonds was investigated using the iron(IV)-oxo complex [(N4Py)Fe-IV(O)](2+) and the N-hydroxyphthalimide (NHPI) mediator. Kinetic analyses showed that [(N4Py)Fe-IV(O)](2+) exhibited higher reactivity for S-oxidation, while HAT was favored in the reactions promoted by NHPI oxidation. Product analysis confirmed these results, with sulfoxides being the major products in the oxidation promoted by [(N4Py)Fe-IV(O)](2+), and HAT-derived products being obtained in higher yields when NHPI was used as a mediator.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Johann B. Kasper, Laia Vicens, C. Maurits de Roo, Ronald Hage, Miquel Costas, Wesley R. Browne
Summary: Mononuclear MnII oxidation catalysts with aminopyridine-based ligands achieve high TON enantioselective epoxidation of alkenes with H2O2. The electronic effect of peripheral ligand substituents plays a role in the enantioselectivity and maximum TON. The use of low temperatures and slow addition of H2O2 reduces competing H2O2 disproportionation and improves TONs for alkene oxidation.
Article
Chemistry, Multidisciplinary
Arnau Call, Giorgio Capocasa, Andrea Palone, Laia Vicens, Eric Aparicio, Najoua Choukairi Afailal, Nikos Siakavaras, Maria Eugenia Lopez Salo, Massimo Bietti, Miquel Costas
Summary: This research report presents a simple and general method for the synthesis of chiral γ-lactones through enantioselective oxidation of nonactivated primary and secondary C(sp(3))-H bonds in readily available carboxylic acids. The use of robust sterically encumbered manganese catalysts allows for outstanding enantioselectivities (up to >99.9%) and yields (up to 96%) using hydrogen peroxide as the oxidant. The resulting γ-lactones are of immediate interest for the preparation of natural products and recyclable polymeric materials.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Sergio Sisti, Marco Galeotti, Filippo Scarchilli, Michela Salamone, Miquel Costas, Massimo Bietti
Summary: A detailed study on C(sp(3))-H bond oxygenation reactions catalyzed by [Mn(OTf)(2)((TIPS)mcp)] complex was conducted, showing that the introduction of electron-withdrawing functional groups in different solvents significantly increased site-selectivity and product yield. The study also achieved selective control over multiple methylenic sites.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Andrea Palone, Guillem Casadevall, Sergi Ruiz-Barragan, Arnau Call, Siilvia Osuna, Massimo Bietti, Miquel Costas
Summary: This study describes a catalytic enantioselective hydroxylation method of tertiary C-H bonds in cyclohexane scaffolds using an evolved manganese catalyst and H2O2. The catalytic system provides structural complementarity to the substrate similarly to lock-and-key recognition in enzymatic active sites. Theoretical calculations reveal that enantioselectivity is determined by the precise fitting of the substrate scaffold into the catalytic site through a network of complementary weak non-covalent interactions. Stereoretentive C(sp(3))-H hydroxylation results in the generation of multiple stereogenic centers in a single step, which can be orthogonally manipulated to obtain a variety of chiral scaffolds from a single precursor molecule.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
