State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Angew Chem Int Ed Engl. 2018 Feb 12;57(7):1808-1812. doi: 10.1002/anie.201710074. Epub 2018 Jan 16.
Tungsten carbide was employed as the catalyst in an atom-economic and renewable synthesis of para-xylene with excellent selectivity and yield from 4-methyl-3-cyclohexene-1-carbonylaldehyde (4-MCHCA). This intermediate is the product of the Diels-Alder reaction between the two readily available bio-based building blocks acrolein and isoprene. Our results suggest that 4-MCHCA undergoes a novel dehydroaromatization-hydrodeoxygenation cascade process by intramolecular hydrogen transfer that does not involve an external hydrogen source, and that the hydrodeoxygenation occurs through the direct dissociation of the C=O bond on the W C surface. Notably, this process is readily applicable to the synthesis of various (multi)methylated arenes from bio-based building blocks, thus potentially providing a petroleum-independent solution to valuable aromatic compounds.
碳化钨作为催化剂，在原子经济性和可再生的合成对二甲苯中具有出色的选择性和产率，原料为 4-甲基-3-环己烯-1-甲醛（4-MCHCA）。这种中间体是丙烯醛和异戊二烯这两种易得的生物基构建块之间狄尔斯-阿尔德反应的产物。我们的研究结果表明，4-MCHCA 通过分子内氢转移经历了一种新颖的脱氢芳构化-氢脱氧级联反应，该过程不涉及外部氢源，而氢脱氧则是通过 W C 表面上 C=O 键的直接解离来实现的。值得注意的是，该过程易于应用于从生物基构建块合成各种（多）甲基取代芳烃，从而为有价值的芳烃化合物提供了一种非石油依赖的解决方案。
