Thianthrene 5-Oxide as a Mechanistic Probe in Oxygen Transfer Reactions: The Case of Carbonyl Oxides versus Dioxiranes Revisited

✍ Scribed by Waldemar Adam; Dieter Golsch; Felix Christian Görth

• Book ID: 102792714
• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 507 KB
• Volume: 2
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.19960020304

✦ Synopsis

Thianthrene 5-oxide (SSO) constitutes a useful mechanistic tool for the assessment of the electronic character of oxygen transfer agents by means of their X,, values, which reflect the extent of nucleophilic oxidation at the SO site in SSO. Treatment of dioxiranes 1 a-d with the SSO probe confirms that these are electrophilic oxidants (Xso < 0.15). Dioxirane sulfoxidation is sensitive to protic solvents and acids, which implies a polar mechanism (S,2) with nucleophilic attack of the sulfide electron pair on the dioxirane peroxide bond. In contrast, the carbonyl ox-ides 2a and b, diethyl persulfoxide (3), and adamantylideneadamantane perepoxide (4) are nucleophilic oxidants (Xso > 0.85). However, the cyclopentadienone carbonyl oxides 2c and d show low Xso values typical for electrophilic oxygen transfer agents. For these car-