Anchoring palladium acetate onto imine-functionalized silica gel through coordinative attachment: An effective recyclable catalyst for the Suzuki-Miyaura reaction in aqueous-isopropanol

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• 作者：Chandan Sarmah ; Debojeet Sahu ; Pankaj Das ; ^{pankajd29@yahoo.com}
• 关键词：Suzuki&ndash ; Miyaura reaction ; Schiff-base condensation ; Supported catalyst ; Coordinative attachment ; Aqueous-isopropanol
• 刊名：Catalysis Today
• 出版年：2012
• 出版时间：30 December, 2012
• 年：2012
• 卷：198
• 期：1
• 页码：197-203
• 全文大小：698 K

文摘

Silica supported palladium catalyst, Pd@imine-SiO₂, was prepared by immobilizing Pd(OAc)₂ onto silica gel through coordination of imine, generated via Schiff-base condensation between 3-aminopropyltriethoxysilane (APTES) functionalized silica gel and acetamide. The catalyst was characterized by FTIR, BET surface area measurements, XRD, SEM-EDX and ICP-AES. The imine-based catalyst, exhibited excellent activity for the Suzuki-Miyaura cross-coupling reactions of aryl halides with arylboronic acids in ⁱPrOH/H₂O (1:1) under mild conditions (T = 60 ¡ãC, air, 0.08 mol % of palladium). Interestingly, under the same experimental conditions, for the reaction between p-bromoanisole and phenylboronic acid the imine-based catalyst, Pd@imine-SiO₂, exhibited comparable result with that of homogeneous Pd(OAc)₂ and much higher activity than amine-based catalyst, Pd@APTES-SiO₂. Furthermore, the imine-based catalyst could be recovered by simple filtration and reused several times without significant loss of activity.