Kinetics of the Enolisation Reactions of 3-Acetyl-2,5-dimethylfuran and of 2-Acetylselenophene

✍ Scribed by Paolo De Maria; Antonella Fontana; Gabriella Siani; Domenico Spinelli

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 347 KB
• Volume: 1998
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199809)1998:9<1867::aid-ejoc1867>3.0.co;2-m

✦ Synopsis

Rate constants for the enolisation reactions of title reactivities in the acid-catalysed reactions. Brønsted β values and isotope effects, k H /k D , point to a more symmetrical compounds have been measured by their rates of halogenation at 25 °C in water, in several buffers, in dilute transition state for the investigated acetyl heterocycles than that for acetophenone in the general base-catalysed reaction. hydrochloric acid, in dilute sodium hydroxide, and in the presence of some metal ion salts. The results have been Metal-activating factors (MAF), i.e. the catalytic constant for metal-ion (Cu 2+ , Zn 2+ , and Ni 2+ ) catalysis, k M , relative to that compared with those previously obtained from the corresponding reactions of acetophenone and a number of for proton catalysis, k H , are discussed as an empirical measure of the "hard or soft" character of the carbonyl other acetyl heterocycles. Electronegativity of the heteroatoms and the "π-excessive" nature of the heterocyclic groups in acyl heterocycles. rings appear to be the main factors determining the relative