Photoinduced reactions. XLIV. Reactivity of singlet oxygen toward methoxybenzenes.

✍ Scribed by Isao Saito; Teruo Matsuura

• Publisher: Elsevier Science
• Year: 1970
• Tongue: French
• Weight: 211 KB
• Volume: 11
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)89327-2

✦ Synopsis

It is well known that, in the dye-sensitized photooxidation of olefins and dienea involving singlet ox.ygen, electron-donating substituents increases the reaction rate. *) In accordance with this, re previously reported the first example of the addition of singlet oxygen to some t-butylated methoxybenzenes. 3) We nor wish to report that the substitution of methox.yl groups to a bensene ring in appropriate positions causes the addition of singlet ox,ygen to the aromatic nuclei.

A series of methoxybenzenes(Ia -11) was photooxidized in methanol solution containing rose bengal as a sensitizer. 4) Among them, Ig and Ii-11 consumed smoothly an equimolar amount of oxygen, while Ia-If and Ih were found to be unreactive. Relative rates of photooxidation of 1s and Ii--I1 uere compared with the values of the half-wave oxidation potentials