Chemo-, regio- and stereo-selective aerial oxidation of limonene to the endo-1,2-epoxide over Mn(Salen)-sulfonated SBA-15

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• 作者：Lakshi Saikia ; D. Srinivas and Paul Ratnasamy
• 关键词：Aerial oxidation of limonene ; Chemo- ; regio- and stereo-selective epoxidation ; Catalysis by Mn(Salen) complexes ; Sulfonic acid-functionalized SBA-15 ; Immobilized Mn Schiff base complexes ; Mesoporous molecular sieves ; Mukaiyama-type oxidation
• 刊名：Applied Catalysis A: General
• 出版年：2006
• 出版时间：17 July 2006
• 年：2006
• 卷：309
• 期：1
• 页码：144-154
• 全文大小：698 K

文摘

Mn(Salen) complexes immobilized on sulfonic acid-functionalized SBA-15 molecular sieves (SBA-15-pr-SO₃-Mn(Salen)) catalyze the Mukaiyama-type oxidation of R-(+)-limonene selectively to the 1,2-epoxide with molecular oxygen at 298 K (Salen = N,N-ethylenebis(salicylidenaminato)). The endo-diastereomer is formed with a diasteromeric excess of 39.8 % . This catalyst exhibited higher catalytic activity than “neat” Mn(Salen) complexes directly supported on SBA-15 or zeolite-Y. A change in the oxidation state of Mn from +3 in the “neat” complex to +2 when immobilized on the sulfonated surface is a probable cause for the observed enhancement of catalytic activity. A part of the Mn complexes was leached out of the solid phase during the reaction.