Article
Chemistry, Multidisciplinary
Nils Ansmann, Thaddaus Thorwart, Lutz Greb
Summary: The Lewis superacid bis(perchlorocatecholato)silane catalyzes C-O bond metathesis of alkyl ethers with high efficiency, enabling chemoselective ring contractions of macrocyclic crown ethers and unprecedented ring-closing metathesis of polyethylene glycols for polymer-selective degradation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Sambasivarao Kotha, Deepshikha Singh, Vijayalakshmi Bandi
Summary: An efficient and short synthetic sequence for highly functionalized urazole derivatives has been reported. N-substituted-1,2,4-triazoline-3,5-dione (TAD) was used as a versatile synthetic reagent. Simple reactions including allylation, ring-closing metathesis, and hydrogenation were successfully employed to construct oxygenated urazole derivatives, which may have implications in medicinal chemistry and organic synthesis.
Article
Chemistry, Organic
Frank Schmidt, Aparna Viswanathan Ammanath, Friedrich Goetz, Martin E. Maier
Summary: A new synthesis route was established for the macrolactone antibiotic berkeleylactone A. The synthesis involved ring-closing alkyne metathesis (RCAM) of an ester substrate with 1-propynyl termini. The carboxylic part of the substrate was assembled using alkyne chemistry, while the alcohol part of the ester was synthesized through propylene oxide opening and triple bond migration reactions. After successful RCAM, the triple bond was selectively hydrogenated and the 4,5-diol was oxidized to obtain the desired derivative. The thioether formation and reduction of the 8,9-double bond were also achieved. However, the antimicrobial activity of the analog was found to be slightly reduced.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Damien F. Dewez, Christina Diacofotaki, Gwilherm Evano
Summary: A new class of nitrogen-containing heterocycles featuring both a cyanamide and an unsaturated ring can be readily obtained through ring-closing metathesis. These compounds have potential applications in drug discovery and can serve as building blocks. The presence of the endocyclic double bond provides a useful access to novel polycyclic heterocycles.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Polymer Science
Yujin Cha, JiHyeon Hwang, Luis Ramos, Huina Lin, Tianyu Zhu, Chuanbing Tang
Summary: The synthesis of cyclic cobaltocenium and its application in the synthesis of high-performance copolymers have been reported.
Article
Chemistry, Multidisciplinary
Sambasivarao Kotha, Balaji U. Solanke
Summary: This article describes an easy-to-execute strategy for synthesizing benzofurans, 2H-chromenes, and benzoxepines using Claisen rearrangement and ring-closing metathesis as key steps, and includes examples of natural products and pharmaceuticals containing these structural elements.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Sambasivarao Kotha, Balaji U. U. Solanke
Summary: This article presents an easy-to-execute strategy for the synthesis of benzofurans and benzoxepines using Claisen rearrangement and ring-closing metathesis. The compounds synthesized through this method are important for drug development and the design of natural products.
Article
Chemistry, Multidisciplinary
Sambasivarao Kotha, Balaji U. Solanke
Summary: We present a novel approach to a library of multidimensional O-heterocycles based on a rigid, tetrahedral core. New derivatives of tetraphenylmethane (TPM) were synthesized using Claisen rearrangement (CR) and ring-closing metathesis (RCM). These compounds include mono-, di-, tri-, and tetra-substituted benzofurans, 2H-chromenes, and benzoxepine derivatives. The incorporation of various heterocyclic cores, commonly found in natural products and pharmaceuticals, as well as the versatility of the tetrahedral framework make this approach significant for the construction of complex molecules. The synthesis of five-, six-, and seven-membered O-heterocycles in the TPM core, along with the base-catalyzed inexpensive synthesis of isomerized intermediates, represents important advancements in the field.
Article
Polymer Science
Mohammad Yasir, Andreas F. M. Kilbinger
Summary: Norbornene and cyclohexene show different polymerization behaviors using Grubbs' catalysts due to their varying ring strain energy levels; a sequence-selective cascade polymerization of a monomer containing both rings resulted in polymers with moderate molecular weight dispersities and good control over molecular weight.
Article
Chemistry, Organic
Rene Hommelsheim, Heliana Michaela Nunez Ponce, Khai-Nghi Truong, Kari Rissanen, Carsten Bolm
Summary: Through the multicomponent Petasis reaction, a variety of NH-sulfoximines and boronic acids can react with glyoxalic acid to yield 2-substituted acetic acids with N-bound sulfoximidoyl groups. This protocol offers high yields, operates under metal-free conditions at ambient temperature, and has short reaction times. Additionally, the potential of 2-sulfoximidoyl acetic acids as building blocks for synthesizing sulfoximine-based benzodiazepine analogues has been demonstrated.
Article
Chemistry, Organic
Nabin Parui, Tirtha Mandal, Jyotirmayee Dash
Summary: An efficient one-step method was used to synthesize various substituted indenones through Grignard addition to indene-1,3-dione, allowing for regiospecific control. This method offers a convenient route to access natural products such as neo-lignans and isoampelopsin D analogues. Additionally, diallyl indenones were synthesized and used as precursors for the facile synthesis of substituted fluorenone derivatives through a ring-closing metathesis (RCM) and aromatization sequence.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Sambasivarao Kotha, Deepshikha Singh
Summary: In this paper, three simple methods for the synthesis of pyrrole derivatives starting with commercially available amines were reported. The first method achieved one-pot ring closing metathesis (RCM) and aromatization sequence using Grubbs first-generation catalyst (G-I), without the use of any additional reagents. The second and third methods relied on the condensation of 2,5-hexanedione/2,5-dimethoxy tetrahydrofuran in the presence of a low melting mixture of N, N'-dimethylurea (DMU) and L-(+)-tartaric acid (TA) and glacial acetic acid, resulting in substituted pyrroles with excellent yield. The photophysical properties of these molecules were also studied by fluorescence spectroscopic data, showing good quantum yield (OF).
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Biochemistry & Molecular Biology
Ervin Kovacs, Bence Balterer, Nguyen Anh Duc, Gyorgyi Szarka, Michael C. Owen, Attila Domjan, Bela Ivan
Summary: A large number of organic solvents contaminate the environment on a daily basis worldwide. This study demonstrates that benzotrifluoride can be used as a suitable solvent for olefin metathesis reactions, providing high yields and similar or even higher reaction rates compared to dichloromethane.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Dmitry S. Belov, Gabriela Tejeda, Charlene Tsay, Konstantin V. Bukhryakov
Summary: Vanadium-based catalysts have been demonstrated to catalyze ring-closing olefin metathesis reactions by well-defined V chloride alkylidene phosphine complexes, exhibiting good functional group tolerance. The properties of the imido group and phosphine were found to play a crucial role in the stability of active intermediates.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Andrea Ojeda-Porras, Remi Aouzal, Claire Wilson, Joelle Prunet
Summary: Two synthetic routes for the ABC tricycle of Taxol are presented, both involving a relay ring-closing metathesis reaction to form the central B ring. In the first approach, the extender arm is positioned on the A ring, while the C ring bears the relay tether in the second route. Despite the efficient synthesis of metathesis precursors with diverse extender arms, the crucial metathesis reactions failed to yield the target compounds in all cases.
