Synthesis of Itaconic Acid Ester Analogues via Self-Aldol Condensation of Ethyl Pyruvate Catalyzed by Hafnium BEA Zeolites
作者:Yuran Wang、Jennifer D. Lewis、Yuriy Román-Leshkov
DOI:10.1021/acscatal.6b00561
日期:2016.5.6
Lewis acidic zeolites are used to synthesize unsaturated dicarboxylic acidesters via aldol condensation of keto esters. Hafnium-containing BEA (Hf-BEA) zeolites catalyze the condensation of ethyl pyruvate into diethyl 2-methyl-4-oxopent-2-enedioate and diethyl 2-methylene-4-oxopentanedioate (an itaconic acidester analogue) with a selectivity of ca. 80% at ca. 60% conversion in a packed-bed reactor
路易斯酸性沸石用于通过酮酯的羟醛缩合来合成不饱和二羧酸酯。含的BEA(Hf-BEA)沸石催化丙酮酸乙酯缩合成2-甲基-4-氧代戊二烯-2-烯二酸二乙酯和2-亚甲基-4-氧代戊二烯酸二乙酯(衣康酸酯类似物) 。约80%在填充床反应器中60%的转化率。催化剂在运行中可稳定132小时,达到5110 mol EP mol Hf –1的周转数。分析Hf-BEA在流动条件下的动力学行为以及用Na交换沸石进行的研究表明,Hf(IV)的开放位点具有路易斯和布朗斯台德酸催化的双重功能。