Carboxylic acid

About: Carboxylic acid is a research topic. Over the lifetime, 48544 publications have been published within this topic receiving 605696 citations.

Chiral Carboxylic Acid Enabled Achiral Rhodium(III)-Catalyzed Enantioselective C−H Functionalization

Abstract: Reported is an achiral Cpx RhIII /chiral carboxylic acid catalyzed asymmetric C-H alkylation of diarylmethanamines with a diazomalonate, followed by cyclization and decarboxylation to afford 1,4-dihydroisoquinolin-3(2H)-one. Secondary alkylamines as well as nonprotected primary alkylamines underwent the transformation with high enantioselectivities (up to 98.5:1.5 e.r.) by using a newly developed chiral carboxylic acid as the sole source of chirality to achieve enantioselective C-H cleavage by a concerted metalation-deprotonation mechanism.

Palladium-catalyzed regioselective aerobic oxidative C-H/N-H carbonylation of heteroarenes under base-free conditions.

Abstract: Using air as oxidant and a balloon pressure of CO, indoles, thiophenes and benzothiophenes are converted in the presence of different alcohols into carboxylic acid esters.

Dehydration of glucose to organic acids in microporous pillared clay catalysts

Abstract: Glucose is an abundant and renewable feedstock for chemicals production The objective of this study was to determine if microporous pillared-clay catalysts could promote the shape-selective, partial dehydration of glucose to organic acids Iron-, chromium-, and aluminum-pillared montmorillonite catalyst powders were prepared The iron-pillared montmorillonite had the most open pore structure in the > 10Arange Pore slit widths of at least 10Aallowed the 86Aglucose molecule to diffuse and react directly within the catalyst micro- and meso-pores Each catalyst powder was reacted with 075 M glucose solution (4 g catalyst/150 ml) within a well-mixed Parr autoclave reactor for 0–24 h at temperatures ranging from 130–170°C All of the catalysts tested promoted four acid-catalyzed reactions: isomerization of glucose to fructose, partial dehydration of glucose to 5-hydroxymethylfurfural (HMF), rehydration and cleavage of HMF to formic acid and 4-oxopentanoic acid, and coke formation The Fe-pillared montmorillonite provided the highest glucose conversion rate, with 100% glucose conversion attained within 12 h at 150°C This catalyst also provided the lowest selectivity of the HMF (the reaction intermediate) and the highest selectivity of formic acid (the final product) in the bulk phase at an optimum temperature of 150°C Apparently, the fraction of pores in the 10–25Arange allowed glucose to diffuse into the microporous matrix, but also trapped the bulky HMF molecule within the micropores, thus directing the reaction scheme to the final organic acid products However, 4-oxopentanoic acid selectivities were low ( < 20%), and coke formation was as high as 04 g coke/g catalyst, implying carbonization of final reaction products

Selenosulfonation of acetylenes: preparation of novel β-(phenylseleno)vinyl sulfones and their conversion to acetylenic and β-functionalized sulfones

Abstract: Etude de l'addition 1,2 du p-tolueneselenosulfonate de Se-phenyle sur les ethynyl benzene, decyne-1, butyne-3ol-1 diphenylacetylene et propiolate de methyle