Donor-acceptor cyclopropanes with two geminal carboxylic esters are reacted with chalcogenyl chlorides and bromides to afford ring-opened products bearing the halogen atoms in the 1-position, adjacent to the donor, and the chalcogenyl residue in the 3-position next to the two acceptor groups. A variety of different donors (e.g., aryl, N, and O) are used. The stereospecificity of the reaction is demonstrated by using a chiral starting material.
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http://dx.doi.org/10.1021/acs.orglett.6b03375 | DOI Listing |
Nature
January 2025
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
Crosslinked thermosets are highly durable materials, but overcoming their petrochemical origins and inability to be recycled poses a grand challenge. Many strategies to access crosslinked polymers that are bioderived or degradable-by-design have been proposed, but they require several resource-intensive synthesis and purification steps and are not yet feasible alternatives to conventional consumer materials. Here we present a modular, one-pot synthesis of degradable thermosets from the commercially available, biosourced monomer 2,3-dihydrofuran (DHF).
View Article and Find Full Text PDFJ Mol Graph Model
January 2025
Unit of Excellence in Computational Molecular Science and Catalysis, and Division of Chemistry, School of Science, University of Phayao, Phayao, 56000, Thailand. Electronic address:
Monomer insertion, leading to the formation of an activated monomer complex, is a critical step in cationic ring-opening polymerization (CROP) of cyclic monomers, such as ε-caprolactone (CL). In this study, Density Functional Theory (DFT) calculations were employed to investigate the structural and electronic properties of four activated complexes at two Zr:B ratios (1:2 and 1:1), where Zr is the cationic zirconocene catalyst, Cp₂ZrMe⁺, and B is the borate cocatalyst, [MeB(CF)] or [B(CF)]. Steric hindrance at the reactive site was analyzed using topographic steric maps, while inter- and intramolecular interactions of the complex systems were examined through the Quantum Theory of Atoms in Molecules (QTAIM) and non-covalent interaction (NCI) analyses.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China. Electronic address:
This study is the first to use synthetic biological omics technology to analyze the molecular mechanism underlying deep degradation of TNT, to construct an artificial transformation system to create engineered Escherichia coli bacteria, and to use Bacillus subtilis as an expression host to explore the mechanism driving the reshaping of the deep degradation platform on microecology. Nitroreductase family protein, 2-oxoacid:acceptor oxidoreductase, NADPH-cytochrome P450 reductase, monooxygenase, ring-cleaving dioxygenase, and RraA family protein significantly participated in the reduction-hydroxylation-ring opening cleavage of TNT, achieving deep transformation of TNT to produce pyruvic acid and other products that entered the cellular metabolic cycle. The key toxic metabolic pathways of TNT, 2,4-diamino-6-nitrotoluene, 2,4,6-triaminotoluene, and 2,4,6-trihydroxytoluene are pantothenate and CoA biosynthesis.
View Article and Find Full Text PDFSci Adv
January 2025
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China.
Heteroarene skeletal editing is gaining popularity in synthetic chemistry. Transmuting single atoms generates molecules that have distinctly varied properties, thereby fostering potent molecular exchanges that can be extensively used to synthesize functional molecules. Herein, we present a convenient protocol for nitrogen-carbon single-atom transmutations in isoquinolines, which is inspired by the Wittig reaction and enables easy access to substituted naphthalene derivatives.
View Article and Find Full Text PDFChemSusChem
January 2025
Peking University, Chemistry, 292 Chengfu Rd, 100871, Beijing, CHINA.
Polyesters featuring a linear topology and in-chain 1,3-cyclobutane rings, synthesized via ring-opening polymerization (ROP) of 2-oxabicyclo[2.1.1]hexan-3-one (4R-BL, R = Bu, Ph) through a coordination-insertion mechanism, display excellent thermal and hydrolytic stability, making them promising candidates for sustainable circular materials.
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