Refernces
10.1039/b411111g
The research focuses on the development of a simple solid phase diversity linker strategy using enol phosphonates for combinatorial chemistry. The main objective was to create stable, storable polymer-bound lactam enol phosphonates on polystyrene resin, which could be released using Suzuki cross-coupling conditions to yield 2-arylenamides. The experiments involved the synthesis of enol phosphonates by reacting phenol with phenylphosphonic dichloride in the presence of a base, followed by combination with p-cresol to form the desired phenyl phosphonate. The study explored the stability and reactivity of these compounds in cross-coupling reactions and attempted to address issues related to homo-coupling of boronic acids. The analyses used included 31P NMR spectroscopy to confirm the presence of phosphonate on the resin and to monitor the progress of the reactions. The yields of the final products were determined after purification and isolation, with the results indicating moderate to good overall yields for the 2-arylenamides.
10.1007/s11172-010-0175-3
The research focuses on a novel method for the thiomethylation of phenols, which are considered promising as antioxidants and bioantioxidants. The study aims to improve upon existing synthesis methods that typically involve intermediate products containing a methylene fragment in the phenol molecule, which are often slow and require harsh conditions. The researchers introduce alkyl diethylaminomethyl sulfides as efficient reagents for introducing alkylthiomethyl groups into phenols, demonstrating high conversion rates and yields. Key chemicals used in the process include diethylaminomethyl dodecyl sulfide (1a), diethylaminomethyl octadecyl sulfide (1b), 2,6-dimethylphenol, p-cresol, and phenol. The conclusions drawn from the study highlight the simplicity and efficiency of the proposed method, which selectively produces mono- and disubstitution products with a preference for ortho-substitution under the tested conditions, and suggest that the reagents used are promising for further testing with other nucleophiles.
10.1021/ja029059r
The research focuses on elucidating the supramolecular structure of benzoxazine oligomers using a combination of molecular modeling, density functional theory (DFT) calculations, and advanced solid-state nuclear magnetic resonance (NMR) experiments. The study characterizes intramolecular hydrogen bonds as the driving forces behind the ring-shaped and helical conformations observed in trimeric and tetrameric units. The experiments involved the synthesis of model trimer and tetramer structures, which were then subjected to fast magic-angle spinning (MAS) 1H NMR spectra to assign resonances of protons forming hydrogen bonds. The experiments use n-hexane, acetone, chloroform, methylamine, p-cresol, and formaldehyde as solvents and reagents. DFT-based geometry optimizations and 1H chemical-shift calculations were used to validate and refine the structural models. Additional analyses included homonuclear 1H-1H double-quantum NMR spectra to identify local proton-proton proximities and quantitative 15N-1H distance measurements obtained from dipolar spinning sideband patterns. These experimental and computational approaches collectively supported the proposed helical geometry of the benzoxazine polymer, which could account for the material's unique chemical properties.
T,
Xi
T:Toxic;
