Aerobic Oxidation Catalysis by a Molecular Barium Vanadium Oxide

作者：Lechner Manuel; Kastner Katharina; Chan Chee Jian; Guettel Robert; Streb Carsten^*

来源：Chemistry - A European Journal, 2018, 24(19): 4952-4956.

DOI：10.1002/chem.201706046

• catalysis
• oxidation
• polyoxometalate
• polyoxovanadate
• self-assembly

Aerobic catalytic oxidations are promising routes to replace environmentally harmful oxidants with O-2 in organic syntheses. Here, we report a molecular barium vanadium oxide, [Ba-4(dmso)(14)V14O38(NO3)] (={Ba4V14}) as viable homogeneous catalyst for a series of oxidation reactions in N,N-dimethyl formamide solution under oxygen (8bar). Starting from the model compound 9,10-dihydroanthracene, we report initial dehydrogenation/ aromatization leading to anthracene formation; this intermediate is subsequently oxidized by stepwise oxygen transfer, first giving the mono-oxygenated anthrone and then the di-oxygenated target product, anthraquinone. Comparative reaction analyses using the Neumann catalyst [PV2Mo10O40](5-) as reference show that oxygen diffusion into the reaction mixture is the rate-limiting step, resulting in accumulation of the reduced catalyst species. This allows us to propose improved reactor designs to overcome this fundamental challenge for aerobic oxidation catalysis.

• 出版日期2018-4-3