Selective aerobic hydroxylation of p-menthane to dihydroterpineols catalyzed by metalloporphyrins in solvent and additive free system
•Metalloporphyrin catalyzed aerobic hydroxylation of p-menthane was investigated.•Tertiary CH bonds were more active than secondary and primary CH bonds.•Dihydroterpineols could be obtained in high selectivity from this system.•The effects of reaction conditions and catalysts' center metals were investigated.
Metallodeuteroporphyrins (MDPs) were employed as the catalysts for aerobic hydroxylation of p-menthane in absence of solvents and additives under ambient pressure. Tertiary CH bonds were found to be more active than secondary and primary CH bonds. Thus, dihydroterpineols (DHTs) could be conveniently obtained in high selectivity. The influences of reaction temperature and catalyst concentration on this reaction were investigated. The impact of central metal on the yield and selectivity of DHTs was discussed. It was found that ferric deuteroporphyrin dimethyl ester (FeClDPDME) and cobalt deuteroporphyrin dimethyl ester (CoDPDME) exhibited higher catalytic activity than other catalysts.
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Journal: Catalysis Communications - Volume 59, 10 January 2015, Pages 26–29