64577-25-9Relevant academic research and scientific papers
Direct reversible decarboxylation from stable organic acids in dimethylformamide solution
Kong, Duanyang,Moon, Patrick J.,Lui, Erica K.J.,Bsharat, Odey,Lundgren, Rylan J.
, p. 557 - 561 (2020/09/02)
Many classical and emerging methodologies in organic chemistry rely on carbon dioxide (CO2) extrusion to generate reactive intermediates for bond-forming events. Synthetic reactions that involve the microscopic reverse-the carboxylation of reactive intermediates-have conventionally been undertaken using very different conditions. We report that chemically stable C(sp3) carboxylates, such as arylacetic acids and malonate half-esters, undergo uncatalyzed reversible decarboxylation in dimethylformamide solution. Decarboxylation-carboxylation occurs with substrates resistant to protodecarboxylation by Br?nsted acids under otherwise identical conditions. Isotopically labeled carboxylic acids can be prepared in high chemical and isotopic yield by simply supplying an atmosphere of 13CO2 to carboxylate salts in polar aprotic solvents. An understanding of carboxylate reactivity in solution enables conditions for the trapping of aldehydes, ketones, and a,b-unsaturated esters.
Palladium-Catalyzed Carbon Isotope Exchange on Aliphatic and Benzoic Acid Chlorides
Gauthier, Donald R.,Rivera, Nelo R.,Yang, Haifeng,Schultz, Danielle M.,Shultz, C. Scott
supporting information, p. 15596 - 15600 (2018/11/23)
An operationally simple protocol for a palladium-catalyzed 13CO and 14CO exchange with activated aliphatic and benzoic carbonyls is presented. Several 13C and 14C building blocks, natural product derivatives, an
Fragment Couplings via CO2 Extrusion-Recombination: Expansion of a Classic Bond-Forming Strategy via Metallaphotoredox
Le, C. Chip,MacMillan, David W. C.
supporting information, p. 11938 - 11941 (2015/10/06)
In this study we demonstrate that molecular fragments, which can be readily coupled via a simple, in situ RO-C=OR bond-forming reaction, can subsequently undergo metal insertion-decarboxylation-recombination to generate Csp2-Csp3 bonds when subjected to metallaphotoredox catalysis. In this embodiment the conversion of a wide variety of mixed anhydrides (formed in situ from carboxylic acids and acyl chlorides) to fragment-coupled ketones is accomplished in good to high yield. A three-step synthesis of the medicinal agent edivoxetine is also described using this new decarboxylation-recombination protocol.
Synthesis and acidity constants of 13CO2H-labelled mono and dipyrrole carboxylic acids. pKa from 13C-NMR
Holmes, Darren L.,Lightner, David A.
, p. 1607 - 1622 (2007/10/02)
Six monocarboxylic acids were prepared highly enriched with 13C in their CO2H groups, and their pKa values were determined at low concentrations 10-4-10-5 M in H2O and in H2O-(CD3)2SO mixtures by analysis of pH-dependent 13CO2H NMR chemical shifts. Plots of the variation of CO2H(CO2-) 13C-NMR chemical shift vs pH gave a typical titration curve from which pKa's for [1-13C]-phenylpropionic (1) and [1-13C]-phenylacetic (2) acids were determined to be 4.60 and 4.16 respectively in H2O, and 4.67 and 4.31 respectively in H2O-27% vol (CD3)2SO. Bilirubin analogs, xanthobilirubic acid (5) and nor-xanthobilirubic acid (6) were determined to have pKa values of 4.76 and 4.64 respectively in H2O-27% vol (CD3)2SO, and extrapolated to pKa values and 4.62 and 4.51 in H2O.
Geminal and Vicinal 13C-13C Coupling Constants in Carboxylic Acid Derivatives
Chaloner, Penny A.
, p. 1028 - 1032 (2007/10/02)
Geminal 13C-13C coupling constants in αβ-unsaturated azlactones and the acids and esters derived from their hydrolysis are large and strongly dependent of configuration.Coupling constants in simple 13C1-labelled carboxylic acids are also reported; vicinal couplings show a strong geometric dependence but the geminal couplings depend mainly on hybridisation.
