5446-96-8Relevant articles and documents
Ligand-free Cu(ii)-catalyzed aerobic etherification of aryl halides with silanes: An experimental and theoretical approach
Ahmed, Muhammad Naeem,Ahmad, Khalil,Yasin, Khawaja Ansar,Farooq, Tayyaba,Khan, Bilal Ahmad,Roy, Soumendra K.
, p. 11316 - 11333 (2019/07/31)
Owing to their wide occurrence in nature and immense applications in various fields, the synthesis of aryl alkyl ethers has remained a focus of interest. In contrast to the conventional/traditional methods of etherification, herein, we have reported a more efficient method, which is better yielding and more general in application. The etherification of aryl halides by alkoxy/phenoxy silanes was catalyzed by copper acetate in the presence of cesium carbonate and oxygen in DMF at 145 °C. All the as-synthesized compounds were characterized via the 1H-NMR and 13C-NMR spectroscopic techniques. Density functional theory calculations using the B3LYP functional were performed to elucidate the reaction mechanism. The C-O coupling reaction between 2-nitroiodobenzene and tetramethoxysilane was used as a model reaction. The activation energy barriers for the generation of catalytic species (31.6 kcal mol-1) and the σ-bond metathesis (16.0 kcal mol-1), oxidative addition/reductive elimination (20.3 kcal mol-1), halogen atom transfer (19.2 kcal mol-1) and single electron transfer (SET) (29.5 kcal mol-1) mechanisms for the C-O coupling reaction were calculated. Calculations for the key reaction steps were repeated with the B3PW91, PBEH1PBE, wB97XD, CAM-B3LYP and mPW1LYP functionals. The formation of catalytic species via a single electron transfer reaction between tetramethoxysilane and copper acetate, formation of methoxy radicals and methoxylation of copper showed an overall energy barrier of 31.6 kcal mol-1, and therefore is the rate determining step.
Facile alkoxyl exchange of 2-methoxybenzoates via nucleophilic aromatic substitution with sodium alkoxides in dimethylformamide
Hattori,Satoh,Miyano
, p. 3840 - 3842 (2007/10/02)
Methyl 2-methoxybenzoate undergoes facile nuclear-methoxyl displacement by treatment with sodium butexide or isopropoxide in dimethylformamide.
Cyclic Nucleotide Phosphodiesterase Inhibition by Imidazopyridines: Analogues of Sulmazole and Isomazole as Inhibitors of the cGMP Specific Phosphodiesterase
Coates, William J.,Connolly, Brendan,Dhanak, Dashyant,Flynn, Sean T.,Worby, Angela
, p. 1387 - 1392 (2007/10/02)
The synthesis and phosphodiesterase (PDE) inhibitory profile of a series of imidazopyridines, including sulmazole and isomazole, on separated PDE isoenzymes are described.The results show that both sulmazole and isomazole are weak inhibitors of PDE III, and their inotropic activity is unlikely to be due to PDE III inhibition alone.Surprisingly, both compounds were found to be significant inhibitors of the cGMP specific isoenzyme, PDE V, and a series of simple 2-substituted phenylimidazopyridines have been made to investigate the SAR of PDE activity.This has been shown to be sensitive to chain length, polarity, and the nature of the heteroatom linking group.Potent PDE V inhibitors, many of which are also significant inhibitors of PDE IV, have been identified.
