Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 200062, Shanghai, China.
ChemistryOpen. 2022 Apr;11(4):e202100301. doi: 10.1002/open.202100301.
The one-pot synthesis of 2,5-furandicarboxylic acid from 2-furoic acid with a yield of 57 % was achieved for the first time using a Pd-catalyzed bromination-hydroxycarbonylation tandem reaction in HOAc-NaOAc buffer. This synthetic protocol shows major improvements compared to previously reported methods, such as using biomass-based 2-furoic acid as low-cost raw material, one-pot synthesis without isolation of intermediate products, and no need for an acidification procedure. Experiments indicate that the involved Xantphos-modified Pd-catalyst and the buffer solution play significant promoting roles for each individual reaction whereas Br (as the brominating reagent) had a negative effect on the second hydroxycarbonylation step, while CO was deleterious for the first bromination step. Hence, in this practical one-pot synthesis, Br should be consumed in the first bromination step as fully as possible, and CO is introduced after the first bromination step has been completed.
首次在 HOAc-NaOAc 缓冲液中使用 Pd 催化的溴化-羟羰基化串联反应，以 57%的收率从 2-糠酸一锅合成 2,5-呋喃二甲酸。与之前报道的方法相比，该合成方法有了显著的改进，例如使用基于生物质的 2-糠酸作为低成本原料、一锅合成而无需分离中间产物以及无需酸化步骤。实验表明，所涉及的 Xantphos 改性 Pd 催化剂和缓冲溶液对每个单独的反应都有显著的促进作用，而 Br（作为溴化试剂）对第二步羟羰基化反应有不利影响，而 CO 对第一步溴化反应有害。因此，在这种实用的一锅合成中，应尽可能完全消耗 Br 进行第一步溴化反应，并且在完成第一步溴化反应后引入 CO。
