92152-56-2Relevant articles and documents
Hydrogen bond-directed assembly of silsesquioxanes cubes: synthesis of carboxylic acid POSS derivatives and the solid state structure of octa[2-(p-carboxyphenyl)ethyl] silsesquioxane
Voisin, Doria,Flot, David,Van der Lee, Arie,Dautel, Olivier J.,Moreau, Joel J. E.
, p. 492 - 502 (2017)
The octa[2-(p-carboxyphenyl)ethyl] and octa[2-(4-carboxy-1,1′-biphenyl)ethyl] silsesquioxane were synthesised under mild reaction conditions upon hydrogenolysis of the corresponding benzyl-ester derivatives. The octa[2-(p-carboxyphenyl)ethyl] silsesquioxane was shown to self-assemble upon formation of carboxylic acid dimers. The presence of eight carboxylic acid functional groups allowed to obtain an ordered silsesquioxane hybrid network. The X-ray crystal structures of the octa-ester and of the octa-acid were determined. The three-dimensional conformation of the ester provided an interpenetrated compact packing of the molecular building blocks without any specific supramolecular interaction. The two-dimensional character of the acid and the directionality of the hydrogen bond pattern of a dimer of acid led to the formation of hydrogen-bonded ribbons. It showed that functionalized silsesquioxane precursors capable of hydrogen bonding are of interest to generate nanostructured materials through self-organization processes. Moreover, the use of carboxylic acid groups is interesting not only because of their ability to form carboxyl dimer structures by hydrogen bonding but also because of their ability to form metal carboxylate derivatives that may lead to new organised hybrid metal organic silica frameworks.
Benzyne-Mediated Esterification Reaction
Li, Yang,Shi, Jiarong,Zhao, Jinlong
supporting information, p. 7274 - 7278 (2021/10/01)
A benzyne-mediated esterification of carboxylic acids and alcohols under mild conditions has been realized, which is made possible via a selective nucleophilic addition of carboxylic acid to benzyne in the presence of alcohol. After a subsequent transesterification with alcohol, the corresponding esters can be produced efficiently. This benzyne-mediated protocol can be used on the modification of Ibuprofen, cholesterol, estradiol, and synthesis of nandrolone phenylpropionate. In addition, benzyne can also be used to promote lactonization and amidation reaction.
Iodine-catalyzed synthesis of β-uramino crotonic esters as well as oxidative esterification of carboxylic acids in choline chloride/urea: a desirable alternative to organic solvents
Moayyed, Mohammadesmaeil,Saberi, Dariush
, p. 445 - 455 (2020/09/07)
Abstract: Iodine-mediated selective synthesis of β-uramino crotonic esters was achieved via the reaction of β-dicarbonyls and urea at room temperature. Choline chloride/urea mixture, as an eco-friendly, cheap, non-toxic, and recyclable deep eutectic solvent (DES), was employed as sustainable media as well as reagent at the same time in these transformations. Some derivatives of β-uramino crotonic esters were synthesized with good to high yields without a tedious work-up. The process could be done to synthesize the above-mentioned compounds in gram scale. Moreover, oxidative cross-esterification of carboxylic acids with alkyl benzenes was carried out in the above-mentioned DES by the employment of tetrabutylammonium iodide (TBAI) as the catalyst and tert-butyl hydroperoxide (TBHP) as the oxidant at 80?°C. DES/TBAI system was reused up to five consecutive times. Graphic abstract: Iodine-catalyzed C–N and C–O bond formation in choline chloride/urea as a green solvent under the mild reaction conditions. Providing the clean procedure toward synthesis of β-uramino crotonic esters and benzylic esters.[Figure not available: see fulltext.].
