3-卤-2(5H)-呋喃酮的无Pd催化脱卤反应

在研究Pd催化的脱卤反应时，意外发现了3-卤-2(5H)-呋喃酮在无Pd催化的情况下也可以发生脱卤反应.在碱为12当量的Et3N、反应溶剂为CH3CN、反应温度150℃、反应时间21 h的优化条件下，产率可达到52%.当底物中存在芳环卤结构时，无钯催化的脱卤反应只脱去呋喃酮3-位上的卤素.这种反应的唯一性与钯催化脱卤反应的组合，可以为多官能团（特别是多卤情况下）非芳基卤底物的选择性脱卤提供更多的控制方法.通过重水实验等研究其反应机理，发现反应体系中的有机碱三乙胺可能是脱卤反应的氢源，但不能完全排除水作为氢源的可能性.

Dehalogenation of 3-halide-2(5H)-furanones in the absence of Pd catalyst

During the studies on the Pd-catalyzed dehalogenation reaction, it was accidentally found that the dehalogenation reaction of 3-halo-2(5H)-furanone also could occur even without any Pd catalysts. Under the optimized reaction conditions, such as base 12 equiv. Et3N, solvent CH3CN, and reaction temperature 150 °C, the best yield can be 52%. For the substrates simultaneously containing aryl halide structure, this Pd-catalyst-free dehalogenation reaction has good selectivity. The combination of this unique selectivity with the Pd-catalyzed dehalogenation reaction can provide many control choices for the selective dehalogenation of the non-aromatic halide substrates with many different functional groups, especially varied halogen atoms. The studies on the reaction mechanism by D2O experiments show that triethylamine is used as not only organic base, but also the hydrogen source of dehalogenation reaction. However, it is difficult to completely remove the possibility of water as a hydrogen source in this reaction.