855207-53-3Relevant articles and documents
Impact of Solvent and Their Contaminants on Pd/C Catalyzed Suzuki-Miyaura Cross-Coupling Reactions
de Lambert de Boisjan, Alexandre,Allemann, Christophe,Fadini, Luca
, (2021/05/17)
The aim of this work was to understand if solvent contaminants can interfere in Suzuki’s cross-coupling reactions and if it can explain the lack of robustness in industrial processes. For this purpose, several parameters were tested on the industrial model reaction between 2-bromonaphthalene and phenylboronic acid catalyzed by Pd/C. Best results were obtained using THF as solvent. Traces of the precursors of the used solvents, such as 2,3-dihydrofurane or maleic anhydride (100–300 ppm related to the solvent) strongly poisoned the reaction, decreasing the conversion significantly. This means that to ensure robust production, solvent quality must be analyzed at the ppm level. Fortunately, addition of triphenylphosphine can circumvent the catalyst poisoning.
Ni-catalyzed carboxylation of C(sp2)- and C(sp3)-O bonds with CO2
Correa, Arkaitz,Leon, Thierry,Martin, Ruben
, p. 1062 - 1069 (2014/02/14)
In recent years a significant progress has been made for the carboxylation of aryl and benzyl halides with CO2, becoming convenient alternatives to the use of stoichiometric amounts of well-defined metal species. Still, however, most of these processes require the use of pyrophoric and air-sensitive reagents and the current methods are mostly restricted to organic halides. Therefore, the discovery of a mild, operationally simple alternate carboxylation that occurs with a wide substrate scope employing readily available coupling partners will be highly desirable. Herein, we report a new protocol that deals with the development of a synergistic activation of CO2 and a rather challenging activation of inert C(sp2)-O and C(sp3)-O bonds derived from simple and cheap alcohols, a previously unrecognized opportunity in this field. This unprecedented carboxylation event is characterized by its simplicity, mild reaction conditions, remarkable selectivity pattern and an excellent chemoselectivity profile using air-, moisture-insensitive and easy-to-handle nickel precatalysts. Our results render our method a powerful alternative, practicality and novelty aside, to commonly used organic halides as counterparts in carboxylation protocols. Furthermore, this study shows, for the first time, that traceless directing groups allow for the reductive coupling of substrates without extended π-systems, a typical requisite in many C-O bond-cleavage reactions. Taking into consideration the limited knowledge in catalytic carboxylative reductive events, and the prospective impact of providing a new tool for accessing valuable carboxylic acids, we believe this work opens up new vistas and allows new tactics in reductive coupling events.
Piperazine-2,3-dicarboxylic acid derivatives as dual antagonists of NMDA and GluK1-containing kainate receptors
Irvine, Mark W.,Costa, Blaise M.,Dlaboga, Daniel,Culley, Georgia R.,Hulse, Richard,Scholefield, Caroline L.,Atlason, Palmi,Fang, Guangyu,Eaves, Richard,Morley, Richard,Mayo-Martin, Maria B.,Amici, Mascia,Bortolotto, Zuner A.,Donaldson, Lucy,Collingridge, Graham L.,Molnár, Elek,Monaghan, Daniel T.,Jane, David E.
experimental part, p. 327 - 341 (2012/03/11)
Competitive N-methyl-d-aspartate receptor (NMDAR) antagonists bind to the GluN2 subunit, of which there are four types (GluN2A-D). We report that some N1-substituted derivatives of cis-piperazine-2,3-dicarboxylic acid display improved relative
NORVALINE DERIVATIVE AND METHOD FOR PREPARATION THEREOF
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Page/Page column 33-34; 56, (2008/06/13)
Norvaline derivative of the formula [I] or pharmaceutically acceptable salt thereof, method for preparing the same, pharmaceutical composition containing the same, and use of said compound for inhibiting transporting activity of glycine transporter type 2 (GlyT2). [wherein X is -CH2-, -O-, -S- or single bond; Ar is optionally substituted aryl or lower cycloalkyl; n is 0 to 2; R1 and R2 are (i) each is hydrogen or lower alkyl; (ii) R1 and R2 are combined to form lower alkylene; or (iii) R1 is hydrogen or lower alkyl and R2 is combined with R4 or R6 to form lower alkylene; R3 and R4 are (i) each is hydrogen or lower alkyl; (ii) R3 and R4 are combined to form lower alkylene; or (iii) R3 is hydrogen or lower alkyl and R4 is combined with R2 or R6 to form lower alkylene; R is or -OR7; R 5 and R6 are (i) each is optionally substituted lower alkyl, or hydrogen; (ii) R5 and R6 are combined to form aliphatic 5- to 6-membered heterocyclic group; or (iii) R5 is optionally substituted lower alkyl or hydrogen and R6 is combined with R2 or R4 to form lower alkylene; R7 is lower alkyl.
Palladium charcoal-catalyzed, ligandless Suzuki reaction by using tetraarylborates in water
Lu, Gang,Franzén, Robert,Zhang, Qian,Xu, Youjun
, p. 4255 - 4259 (2007/10/03)
In water and without using any ligand, palladium charcoal-catalyzed Suzuki coupling reaction of tetraarylborates with aryl bromides could be achieved in excellent yield. A concise mechanism consisting of four catalytic cycles is depicted in this paper.