作者:Fu-Ling Xue、Ji Qi、Pai Peng、Guang-Zhen Mo、Zhao-Yang Wang
DOI:10.2174/15701786113109990041
日期:2014.1.31
During the research on the Pd-catalyzed intramolecular cyclization reaction via C-H activation, the dehalogenation
of 3-halo-2(5H)-furanones is unexpectedly discovered. Under the optimized conditions without any special anaerobic
and anhydrous treatments, using N,N-diisopropylethylamine (DIPEA) simultaneously as hydrogen source and base, the
reactions of 27 substrates with less Pd catalyst (5 mol% Pd(PPh3)4) usually give higher yields (70-99%, mostly over 82%).
Especially for 3-halo-2(5H)-furanone substrates simultaneously containing aryl halide structure, this kind of Pd-catalyzed
dehalogenation has good selectivity. After the selectivity is explained via the substrate theoretical calculation, a possible
reaction mechanism of the Pd-catalyzed dehalogenation is proposed. These novel investigations provide an efficient, simple,
practical and selective Pd-catalyzed dehalogenation method for the non-aromatic halide substrates with many
different functional groups.
在研究 Pd 催化分子内 C-H 活化环化反应的过程中,意外地发现了 3-卤代-2(5H)-呋喃酮的脱卤反应。在无需特殊厌氧和无水处理的优化条件下,同时使用 N,N-二异丙基乙胺(DIPEA)作为氢源和碱,以较少的 Pd 催化剂(5 mol% Pd(PPh3)4)催化 27 种底物的反应,通常可以获得较高的产率(70-99%,大部分超过 82%)。 特别是对于同时含有芳基卤化物结构的 3-卤代-2(5H)-呋喃酮底物,这种 Pd 催化脱卤反应具有良好的选择性。在通过底物理论计算解释了选择性之后,提出了 Pd 催化脱卤反应的可能反应机理。这些新颖的研究为具有多种不同官能团的非芳香族卤化物底物提供了一种高效、简单、实用且具有选择性的钯催化脱卤方法。