Metal-Free Allylic Oxidation with Molecular Oxygen Catalyzed by g-C3N4 and N-Hydroxyphthalimide

• Published in: Catalysis letters Vol. 144; no. 4; pp. 717 - 722
• Main Authors: Liu, Guiyin, Tang, Ruiren, Wang, Zhen
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2014; Springer; Springer Nature B.V
• Subjects: Carbon nitride; Carbonyl compounds; Carbonyls; Catalysis; Catalysts; Catalytic activity; Catalytic converters; Chemistry; Chemistry and Materials Science; Exact sciences and technology; General and physical chemistry; Industrial Chemistry/Chemical Engineering; Nitrogen; Organic compounds; Organometallic Chemistry; Oxidation; Oxygen; Physical Chemistry; Selectivity; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Molecular oxygen; Allylic oxidation; g-C; N; Hydroxyphthalimide; Heterogeneous catalysis; Oxygen; Catalytic reaction; Oxidation; N-Hydroxyphthalimide
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-014-1200-1

Polymeric graphitic carbon nitride (g-C 3 N 4 ) is a layered graphite-like nitrogen-rich material, bearing the potential ability to reductively adsorb molecular oxygen for catalytic allylic oxidation. Furthermore, N -hydroxyphthalimide (NHPI) has been recognized as an efficient catalyst for aerobic oxidation of various organic compounds under mild conditions in the presence of various co-catalysts. We present here a promising strategy for employing such nitride-rich g-C 3 N 4 combined with NHPI to form an all-organic metal-free composite and have examined its activity for allylic oxidation with molecular oxygen as the primary terminal oxidant. In the case of allylic oxidation α-isophorone catalyzed by g-C 3 N 4 /NHPI gave priority to its corresponding carbonyl compound and epoxide. The effects of various reaction conditions on the catalytic reaction were optimized, affording 74.8 % conversion with 44.4 % selectivity of ketoisophorone at 130 °C in 5 h. Repeated runs demonstrated that the catalyst was stable for at least three cycles without noticeable loss of its catalytic activity. Graphical Abstract