Aerobic oxidation of C<sub>4</sub>–C<sub>6</sub> α,ω-diols to the diacids in base-free medium over zirconia-supported (bi)metallic catalysts
作者:Modibo Mounguengui-Diallo、Achraf Sadier、Denilson Da Silva Perez、Clémence Nikitine、Laura Puchot、Youssef Habibi、Catherine Pinel、Noémie Perret、Michèle Besson
DOI:10.1039/c9nj01695c
日期:——
under 40 bar air. The nature of the metallic catalyst influenced the distribution of products as oxidation proceeded. The longer the carbon chain linking the terminal alcohol groups, the higher the yield of the diacid. The best yields of succinic acid, glutaric acid and adipic acid reached 83, 84 and 96% from BDO, PDO and HDO, respectively, over Au–Pt/ZrO2. There was some evidence of decarbonylation
脂族α,ω-二醇的氧化是生产有价值的α,ω-二酸或ω-羟基酸用于各种聚合物合成的潜在有趣途径。1,4-丁二醇(BDO),1,5-戊二醇(PDO)和1,6-己二醇(HDO)特别吸引人,因为它们可以从木质纤维素生物质中获得。在70 bar或90°C的氧化锆上,在40 bar的空气中,在一组Au,Pt,Au-Pt和Au-Pd催化剂上,在水中研究了这些二醇的水有氧氧化成相应的二酸。随着氧化的进行,金属催化剂的性质影响了产物的分布。连接末端醇基的碳链越长,二酸的产率越高。与Au–Pt / ZrO相比,BDO,PDO和HDO的琥珀酸,戊二酸和己二酸的最佳产率分别达到83%,84%和96%2。在反应的早期,有一些证据表明α,ω-羟醛会脱羰。与HDO相比,1,2,6-己三醇中羟基取代基的存在显着降低了氧化速率。此外,在中等碱性介质(NaOH /二醇= 2)中,相对于Au / ZrO 2(90-93%),P