Efficient Oxidative Cleavage of Olefins to Carboxylic Acids with Hydrogen Peroxide Catalyzed by Methyltrioctylammonium Tetrakis(oxodiperoxotungsto)phosphate(3−) under Two-Phase Conditions. Synthetic Aspects and Investigation of the Reaction Course
作者:Ermanno Antonelli、Rino D'Aloisio、Mario Gambaro、Tiziana Fiorani、Carlo Venturello
DOI:10.1021/jo980481t
日期:1998.10.1
The oxidative cleavage of alkenes to carboxylic acids with 40% w/v aqueous hydrogen peroxide catalyzed by methyltrioctylammonium tetrakis(oxodiperoxotungsto)phosphate(3-) (Ia) is reported to occur in high yields and selectivities under two-phase conditions in the absence of organic solvents. On the basis of a study of the reaction, two main reaction pathways leading to acids have been recognized, the
据报道,在四相(氧代二过氧辛酸)磷酸盐(3-)(Ia)催化下,烯烃以40%w / v的过氧化氢水溶液氧化裂解为羧酸,在两相条件下,在不存在二甲苯的情况下,收率高,选择性高。有机溶剂。在对反应的研究的基础上,已经认识到导致酸的两个主要反应途径,第一个涉及过水解,第二个涉及最初形成的环氧化物的水解。“过水解”反应途径似乎在中链和长链烯烃氧化成酸中起主要作用,而在一定程度上干预了芳基烯烃和C(5)-C(7)环烯烃的氧化。通过中间体β-氢过氧醇的分离及其与H(2)O(2)和Ia的酸转化,已证明了该途径的发生。描述了该转变的过程,包括β-氢过氧醇中间体的初始氧化(至α-氧代氢过氧化物)或分解(至羰基化合物)。在内部β-氢过氧醇的情况下,主要的氧化产物α-氢过氧酮已经被分离出来,而带有仲羟基的末端β-氢过氧醇的存在则证明了它们的存在。过氧化氢的浓度似乎对中等酸度有显着影响,并显示了其对反应效率的影响。