Potassium Phosphate as a High-Performance Solid Base in Phase-Transfer-Catalyzed Alkylation Reactions

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• 作者：Nida Qafisheh ; Sudip Mukhopadhyay ; Ashutosh V. Joshi ; Yoel Sasson ; Gaik-Khuan Chuah ; Stephan Jaenicke
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2007
• 出版时间：May 9, 2007
• 年：2007
• 卷：46
• 期：10
• 页码：3016 - 3023
• 全文大小：364K
• 年卷期：v.46,no.10(May 9, 2007)
• ISSN：1520-5045

文摘

Potassium phosphate is reported as a remarkably active and selective solid base in phase-transfer-catalyzedalkylation reactions of alkaline-sensitive substrates such as esters and halides. The performance of potassiumphosphate exceeded that of common bases such as hydroxides, carbonates, fluorides, and oxides. Even thoughpotassium phosphate is not porous and the number of basic sites exposed at the surface is relatively low (0.05mequiv/g), it is still fully consumed in the alkylation process and converted into K₂HPO₄. The heterogeneousprocess follows a second-order rate law, and the rate constant was found to depend strongly on particle size,presence of water in the system, thermal pretreatment of the base, structure of the phase transfer catalyst,nature of the solvent, and reaction temperature. Some surface properties of K₃PO₄ have been determined andare discussed with relevance to the above catalytic alkylation reactions.