922-67-8Relevant articles and documents
Synthesis of 1-methyl-3-oxo-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxylic acid methyl ester
Aragao, Valquiria,Constantino, Mauricio Gomes,Beatriz, Adilson,Da Silva, Gil Valdo Jose
, p. 1413 - 1418 (2005)
A simple and efficient method for the preparation of 1-methyl-3-oxo-7- oxabicyclo[2.2.1]hept-5-en-2-carboxylic acid methyl ester (1) is described. The first step is a highly regioselective Diels-Alder reaction between 2-methylfuran and methyl-3-bromopropiolate. A remarkably difficult ketal hydrolysis reaction was effected by treatment with HCl, a simple reagent that was shown to be more efficient, in this case, than commonly used more elaborate methods.
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Acheson,Verlander
, p. 2311,2313 (1969)
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Environment-friendly preparation method of propiolic acid derivatives
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Paragraph 0031-0034, (2020/02/14)
The invention discloses an environment-friendly preparation method of propiolic acid derivatives. The preparation method comprises the following steps: (1) with 2,3-dibromosuccinic acid as a raw material, generating a butynedioic acid salt under alkaline conditions; (2) under an acidic condition, carrying out high-temperature decarboxylation to obtain propiolic acid; and (3) adding corresponding methanol or ethanol into propiolic acid in an extraction solvent, and preparing high-yield propiolate under acidic catalytic conditions under the condition that trimethyl orthoformate or triethyl orthoformate participates in dehydration. In the invention, the propiolic acid preparation method is friendly to environment and high in safety coefficient; and the method provided by the invention can beused for preparing methyl propiolate and ethyl propiolate, and has the advantages of small alcohol consumption, thorough reaction, high yield and easiness in separation.
Oxidant speciation and anionic ligand effects in the gold-catalyzed oxidative coupling of arenes and alkynes
Hofer, Manuel,De Haro, Teresa,Gómez-Bengoa, Enrique,Genoux, Alexandre,Nevado, Cristina
, p. 8411 - 8420 (2019/09/30)
The mechanism of the gold-catalyzed oxidative cross-coupling of arenes and alkynes has been studied in detail combining stoichiometric experiments with putative reaction intermediates and DFT calculations. Our data suggest that ligand exchange between the alkyne, the Au(i)-catalyst and the hypervalent iodine reagent is responsible for the formation of both an Au(i)-acetylide complex and a more reactive "non-symmetric" I(iii) oxidant responsible for the crucial Au(i)/Au(iii) turnover. Further, the reactivity of the in situ generated Au(iii)-acetylide complex is governed by the nature of the anionic ligands transferred by the I(iii) oxidant: while halogen ligands remain unreactive, acetato ligands are efficiently displaced by the arene to yield the observed Csp2-Csp cross-coupling products through an irreversible reductive elimination step. Finally, the nature of competitive processes and catalyst deactivation pathways has also been unraveled. This detailed investigation provides insights not only on the specific features of the species involved in oxidative gold-catalyzed cross couplings but also highlights the importance of both ancillary and anionic ligands in the reactivity of the key Au(iii) intermediates.