154013-25-9Relevant academic research and scientific papers
Mechanistic Studies of Selective Catechol Formation from o-Methoxyphenols using a Copper(II)-Ascorbic Acid-Dioxygen System
Aihara, Kazuhiro,Urano, Yasuteru,Higuchi, Tsunehiko,Hirobe, Masaaki
, p. 2165 - 2170 (2007/10/02)
Mechanistic details of selective conversion of o-methoxyphenols to the corresponding catechols using a Cu2+-ascorbic acid-O2 system, were studied. 2,5-Dimethoxyphenol was converted predominantly to the o-demethylated compound and partially to the m-demethylated one.Anisole with no phenolic hydroxy group was much less reactive.When guaiacol (1). guaiacol and 2-methoxy-6-methoxyphenol was used as substrates, moderate intermolecular and intramolecular kinetic isotope effects were observed (1.4-1.9). Catechol was derived from 1 in nine-fold excess over catechol when the reaction was run in an 18O2 atmosphere with natural water as a solvent, though no catechol was formed when using natural O2 and H218O.It was determined that the Cu2+-ascorbic acid-O2 system operates in a monooxygenase mode because the oxygen atom of dioxygen (not water) was incorporated into the products, and this oxidative conversion proceeded mainly via ipso-substitution at the methoxy position, probably with hydroxyl radical coordinated to the cupric ion as the active oxygen species.
