Aerobic oxidation of alkyl arenes using a combination of N-hydroxy phthalimide and recyclable cobalt(II) tetrasulfophthalocyanine supported on silica

Recent Advances in Homogeneous Metal-Catalyzed Aerobic C–H Oxidation of Benzylic Compounds

Csp3–H oxidation of benzylic methylene compounds is an established strategy for the synthesis of aromatic ketones, esters, and amides. The need for more sustainable oxidizers has encouraged researchers to explore the use of molecular oxygen. In particular, homogeneous metal-catalyzed aerobic oxidation of benzylic methylenes has attracted much attention. This account summarizes the development of this oxidative strategy in the last two decades, examining key factors such as reaction yields, substrate:catalyst ratio, substrate scope, selectivity over other oxidation byproducts, and reaction conditions including solvents and temperature. Finally, several mechanistic proposals to explain the observed results will be discussed.

Oxidation of p-toluic acid to terephthalic acid via a bromine-free process using nano manganese and manganese–copper mixed oxides

Challenges and technological opportunities for nano-mixed oxide (Cu–Mn) allowing a green route to valued terephthalic acid production from p-xylene.

Sulfonated Co(II) phthalocyanines covalently anchored at organic polymers as catalyst for mild oxidation of mercaptans

Current work is devoted to covalent immobilization of sulfonated derivatives of cobalt phthalocyanines “Merox catalysts” on the surfaces of polypropylene and polyethylene terephthalate. Their catalytic activity in reaction of mild oxidation of sulfur compounds to disulfides with oxygen of the air was studied. Anchoring of the catalyst on this polymer prevents its leaching and promotes its efficient recovering and recycling without significant loss of catalytic activity.

Natural hydroxyapatite supported cobalt tetrasulfophthalocyanine: a green, renewable and biomaterial-based heterogeneous catalyst for selective aerobic oxidation of alkyl arenes and alcohols

Natural hydroxyapatite supported cobalt tetrasulfophthalocyanine (CoTSPc-NHAp) as a green, renewable and biomaterial-based heterogeneous catalyst promotes aerobic oxidation of alkyl arenes and alcohols.

Oxidation of alkylaromatics to aromatic ketones catalyzed by metalloporphyrins under the special temperature control method

The aerobic oxidation of alkylaromatics to aromatic ketones catalyzed by metalloporphyrins under the special temperature control method was systematically investigated. Three novel and key points were found to have significant functions in this process, that is, the special temperature control method (initiation at higher temperature and reaction at lower temperature), the synergistic effect of the composite catalysts comprising cobalt and manganese porphyrins, and the amount of catalysts in the reaction. Subsequently, the effects of substitutes on alkylaromatics were also explored under the same conditions. Results showed that alkylaromatic conversions gradually increased from 8.5% to 54.3% with the para-substituents shifting from the electron-donating group to the electron-withdrawing group (i.e., methoxy < hydro < bromo < acyl < nitro). A possible mechanism for this reaction was also proposed.