Synthetic Transformations Using Molecular Oxygen-Doped Carbon Materials

Area of Science:

• Materials Science
• Organic Chemistry
• Catalysis

Background:

• Activated carbon (AC) is a versatile material with a high surface area.
• Chemisorption of oxygen onto AC creates reactive surface species.
• Understanding these reactive species is key to developing new catalytic applications.

Purpose of the Study:

• To investigate the reactivity of O2-chemisorbed AC with various nucleophiles.
• To explore the potential of AC as a catalyst for oxidative coupling reactions.
• To elucidate the reaction mechanisms involved in these transformations.

Main Methods:

• Chemisorption of oxygen onto activated carbon.
• Reaction of O2-chemisorbed AC with different nucleophiles (PPh3, benzoic acid, amines, β-naphthoxide derivatives).
• Analysis of reaction products using established chemical techniques.

Main Results:

• O2-chemisorbed AC reacts with PPh3 and benzoic acid to form Ph3P═O.
• Amine donors undergo dehydrogenative coupling yielding products in 67-89% yields via radical cation and iminium ion intermediates.
• β-naphthoxide derivatives undergo oxidative coupling to form bi-2-naphthol products in 68-95% yields.

Conclusions:

• Activated carbon serves as an effective platform for oxygen-mediated organic transformations.
• The chemisorbed oxygen species on AC can selectively promote different types of oxidative coupling reactions.
• This study highlights the potential of AC in green chemistry applications for synthesizing valuable organic compounds.