We described a synthetic approach to bisphenol-based monocyanate esters based on mono--methylation of parental bisphenols followed by cyanation of the residual phenolic hydroxyl. Structures of the synthesized compounds were determined by the application of IR, NMR ¹H and C spectroscopies, EI and MALDI mass spectrometry, and purity of the final product was controlled by HPLC. We showed that stability of the cyanate esters depends on the nature of the bridging group. Temperature range of thermally initiated cyclotrimerization of synthesized monocyanate ester, as well as reaction enthalpy, was determined by differential scanning calorimetry (DSC).
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6337567 | PMC |
http://dx.doi.org/10.3390/molecules24010177 | DOI Listing |
Chemistry
January 2025
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences 47 Leninsky Prospect, Moscow, 119991, Russian Federation.
The electrochemically mediated cyanation/annulation process with in situ cyanide ion generation from NHSCN and multi-step oxidative construction of CN-functionalized heterocycles from easily available α-amino esters and pyridine-2-carbaldehydes has been discovered. Depending on the nature of the α-amino ester, 1-cyano-imidazo[1,5-a]pyridine-3-carboxylates, 3-alkyl- and 3-aryl-imidazo[1,5-a]pyridines-1-carbonitriles, and the first reported 4-oxo-4H-pyrido[1,2-a]pyrazine-1-carbonitriles were obtained. The electrosynthesis is carried out in an undivided electrochemical cell under constant current conditions.
View Article and Find Full Text PDFRSC Adv
November 2024
The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital Shenzhen 518035 China
β-Amino acids are essential components in the synthesis of biologically active compounds. However, obtaining them in enantiomerically pure forms remains challenging. This study investigates a safe and efficient method for synthesizing enantiopure N-Boc-β-amino acid methyl esters, incorporating both natural and unnatural side chains.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemistry, Colorado State University, 1301 Center Ave, Fort Collins, CO 80523-1872.
Organoboron compounds are widely utilized in organic synthesis for their diverse reactivity, modular preparation, and stability compared to other classes of organometallic reagents. While organoboron species are commonly employed as nucleophiles in cross-coupling reactions, their potential as racemic building blocks in enantioconvergent transformations remains largely untapped. Herein, we demonstrate the direct utilization of alkylboronic pinacol esters in intermolecular enantioconvergent transformations.
View Article and Find Full Text PDFMater Horiz
October 2024
Shaanxi Key Laboratory of Macromolecular Science and Technology, Key Laboratory of Polymer Science and Technology of Shaanxi Province, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, 710129, China.
Cyanate ester (CE) resins are distinguished by excellent dielectric properties in electronic packaging materials but face significant fire risks, with existing strategies often compromising their processability or original properties. Herein, we propose an innovative strategy involving the exchange of dynamic covalent bonds under heat stimuli aimed at forming a continuous and compact char layer to enhance the fire safety of CE resin. Using a straightforward one-pot method, dynamic Si-O and B-O bonds were integrated into a novel hyperbranched polymer (HPSiB), ensuring good compatibility with CE resin while lowering its peak curing temperature by 185 °C for facile processability.
View Article and Find Full Text PDFJ Chem Inf Model
July 2024
Michigan Technological University, Houghton, Michigan 49931, United States.
Generating simulation-ready molecular models for the LAMMPS molecular dynamics (MD) simulation software package is a difficult task and impedes the more widespread and efficient use of MD in materials design and development. Fixed-bond force fields generally require manual assignment of atom types, bonded interactions, charges, and simulation domain sizes. A new LAMMPS pre- and postprocessing toolkit (LUNAR) is presented that efficiently builds molecular systems for LAMMPS.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!