Shen Hui-Jie, Hu Ze-Nan, Zhang Chi
State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
J Org Chem. 2022 Mar 18;87(6):3885-3894. doi: 10.1021/acs.joc.1c00596. Epub 2021 May 24.
Herein, we report an efficient method for the chemical generation of O by treatment of HO with AIBX, a highly water-soluble, bench-stable, recyclable hypervalent iodine(V) reagent developed by our group. The generation of O was confirmed by the following results: (1) capture of O with the sodium salt of anthracene-9,10-bis(ethanesulfonate) produced the corresponding endoperoxide and (2) TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) produced by the oxidation of 2,2,6,6-tetramethylpiperidine with O generated using the AIBX/HO system was detected by electron spin resonance spectroscopy. To illustrate the potential utility of this method for organic synthesis, we used the AIBX/HO system to perform typical reactions of O: [2 + 2]/[4 + 2] cycloadditions, Schenck ene reactions, and heteroatom oxidation reactions, which afforded the corresponding products in high yields. Moreover, we used the method to synthesize the antimalarial drug artemisinin. Finally, we demonstrated that AIBX could be regenerated after the reaction by means of a workup involving extraction and removal of water to obtain a precursor of AIBX, which could then be re-oxidized.
在此，我们报道了一种通过用AIBX处理HO来化学生成O的有效方法，AIBX是我们小组开发的一种高度水溶性、在实验室稳定、可循环使用的高价碘(V)试剂。O的生成通过以下结果得到证实：(1)用蒽-9,10-双(乙烷磺酸盐)的钠盐捕获O产生了相应的内过氧化物，以及(2)通过电子自旋共振光谱检测到了用AIBX/HO体系生成的O氧化2,2,6,6-四甲基哌啶产生的TEMPO(2,2,6,6-四甲基-1-哌啶氧基)。为了说明该方法在有机合成中的潜在用途，我们使用AIBX/HO体系进行O的典型反应：[2 + 2]/[4 + 2]环加成反应、申克烯反应和杂原子氧化反应，这些反应都以高产率得到了相应的产物。此外，我们使用该方法合成了抗疟药物青蒿素。最后，我们证明了反应后通过涉及萃取和除水的后处理可以使AIBX再生，从而得到AIBX的前体，然后该前体可以被重新氧化。
