A copper(I)‐catalyzed desulfinative carboxylation of sodium sulfinates using carbon dioxide has been developed. This reaction showed wide functional group tolerance. A series of sodium aryl‐ and alkenylsulfinates could be converted into the corresponding carboxylic acids in good to excellent yields. Additionally, the reaction mechanism was studied by in situ NMR analysis and isotopic labeling experiments.
The electrocarboxylation of various aromatic ketones, carried out in N-methyl-2-pyrrolidone (NMP) in a diaphragmless cell equipped with a carbon cathode and an aluminium sacrificial anode, yielded, among the products, the target hydroxy acids, the corresponding alcohols and pinacols and, quite surprisingly, detectable amounts of substituted benzoic acids and cycloexene carboxylic acids. These compounds arise from a never reported before electrocarboxylation on the aromatic ring, respectively, for substitution of an aromatic hydrogen and from an addition reaction. For example, the electrocarboxylation of acetophenone gave rise to the substituted benzoic acids in ortho, para and meta positions, while for 2,2-dimethylpropiophenone the substituted benzoic acid in meta position and the cyclohex-5en-1,3-dicarboxylic acid derivative were detected among the products. 相似文献
The novel syntheses of 4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)benzophenone, 1-[4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)phenyl]-1-phenylethanol and 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole ( 1 ) are described. ω-Oxazolyl polystyrene ( 2 ) was synthesized in quantitative yields by the reaction of poly(styryl)lithium with stoichiometric amounts of 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole ( 1 ) in toluene/tetrahydrofuran (4 : 1 v/v) at −78°C. Deblocking of the oxazoline protecting group by acid hydrolysis followed by saponification quantitatively provides the corresponding aromatic carboxyl chain-end functionalized polystyrene ( 3 ). The functionalization agent and functionalized polymers were characterized by HPLC, thin layer chromatography, size exclusion chromatography, vapor phase osmometry, spectroscopy (1H NMR, 13C NMR and FTIR), potentiometry and elemental analysis. 相似文献
The reactions of propargyl alcohols with carbon dioxide in supercritical carbon dioxide or in acetonitrile with gaseous carbon dioxide in the presence of organic bases as catalysts have been examined. Bicyclic guanidines are effective catalysts for the formation of α‐methylene cyclic carbonates under mild reaction conditions. Oxoalkyl carbonates, oxoalkyl carbamates or α‐methyleneoxazolidinones are obtained in high yields and good selectivities in one‐step starting from propargyl alcohols and an external nucleophile (alcohols or amines) using bicyclic guanidines as catalysts in supercritical carbon dioxide. Propargylic diols under the same reaction conditions underwent a rearrangement process instead of carbon dioxide insertion whereas in the presence of an external nucleophile the formation of oxocarbonates, oxocarbamates or cyclic carbamates was achieved in satisfactory yields. 相似文献