Study on the Novel Radical Reactions with Hypervalent Iodine Compounds

自由基反应是有机合成中最常用的方法之一。因此，开展了三价碘化合物与新型自由基反应的研究。结果发现，在芳环上具有供电子基团的（二酰氧基碘）芳烃在钨灯照射下加速自由基反应性，如下所示，1）在二硫化物存在下羧酸转化为相应的硫化物，2）芳族羧酸转化为相应的γ-或δ-内酯，（3）将含芳环的醇转化为相应的环醚;（4）将含芳环的胺转化为相应的环胺。这些反应通过形成碳、氧和氮中心自由基来进行，操作简单，产率高。在自然界中，存在着许多重要的含氧、氮原子的环状化合物。因此，本方法对于制备这些天然产物是非常有用的。这些结果于1995年在三个国际期刊上发表，其他论文正在准备向期刊投稿。

Radical reactions are one of the most useful methods for organic synthesis. Therefore, the study on the novel radical reactions with trivalent iodine compounds has been carried out. As a result, it was found that (diacyloxyiodo) arenes which has electron-donating group on a aromatic ring accelerated the radical reactivities under the irradiation with tungsten lamp as shown below,1) conversion of carboxylic acids to the corresponding sulfides in the presence of disulfides,2) conversion of aromatic carboxylic acids to the corresponding gamma-or delta-lactones,3) conversion of alcohols bearing a aromatic ring to the corresponding cyclic ethers,4) conversion of amines bearing a aromatic ring to the corresponding cyclic amines,These reactions proceed via the formation of carbon-, oxygen-, and nitrogen-centered radicals to give the products with a simple operation in good yields. In nature, there are many kinds of important cyclic compounds containing oxygen and nitrogen atoms. Therefore, the present method is very useful for the preparation of these natural products. These results were published in three international Journals in 1995, and the other papers are in preparation for the contribution to the Journals.