Mechanism of recyclization of furans to thiophenes and selenophenes under acid-catalysis conditions. 2. Kinetic investigations of the reaction of 2,5-dialkylfurans with hydrogen sulfide and hydrogen selenide in an anhydrous medium

✍ Scribed by S. P. Voronin; T. I. Gubina; S. A. Trushin; I. A. Markushina; V. G. Kharchenko

• Publisher: Springer US
• Year: 1989
• Tongue: English
• Weight: 395 KB
• Volume: 25
• Category: Article
• ISSN: 0009-3122
• DOI: 10.1007/bf00481514

✦ Synopsis

The effect of the concentration of the acidic component on the rates of recyclization of 2,5-dialkylfurans to thiophenes and selenophenes was studied. On the basis of the direct correlation of log k on (Ho)l and the isotope effect of the solvent it was established that the reaction proceeds via a mechanism of specific acid catalysis. It was shown that the rates of the reactions with the participation of hydrogen sulfide and hydrogen selenide coincide ~t equal acidities and temperatures. A scheme for the mechanism of the reaction that includes a step involving the formation of the doubly protonated form of the substrate is proposed.