Joint Research on Chemistry of Hypervalent Compounds

高价化合物的研究是有机化学的重要领域之一。本研究旨在阐明高价化合物在有机反应中的作用，特别是开发新的反应性高价试剂和利用这些试剂进行合成反应。高价碘试剂的研制研究了高活性高价碘试剂的合成。以碘基苯（PhIO）和三氟甲烷磺酸（TfOH）为原料，制备了对苯型比西啶（III）试剂。制备对苯试剂需要两倍摩尔量的TfOH。用2等量的TFOH将碘苯二乙酸酯转化为高活性的碘试剂。此外，邻碘基苯甲酸提供了一种高活性的碘试剂。这些高价碘试剂对芳香族和乙炔类底物具有很高的反应活性，可以高产地生成芳基和炔基碘盐。高价碘化合物的高反应活性高价碘试剂的高反应活性是由于三氟酸基团与碘的高核逸性。芳香环上的吸电子基团增加了反应活性。高价化合物对亲核试剂的高反应活性来源于苯基多尼奥基团的高离开能力。新型高价化合物的合成本研究开发的高活性高价试剂提供了许多新型的高价化合物，如（对苯基）双炔酸盐、炔基酸盐、二芳基酸盐、含羧基的芳基和炔基酸盐、1-芳基苯并噻吩盐及其衍生物，以及液晶二乙炔和苯前体。

The research on hypervalent compounds is the one of the most important fields of organic chemistry. This research was conducted to aim at clarifying the roles of hypervalent compounds in organic reactions, especially, to develope new reactive hypervalent reagents and the synthetic reactions using the reagents.1.Development of Hypervalent ReagentsSynthesis of highly reactive hypervalent iodine reagents were conducted. The p-phenylene type of bisiodine (III) reagents was prepared from iodosylbenzene (PhIO) and trifluoromethanesulfonic acid (TfOH). Double the molar amounts of TfOH were essential to produce the p-phenylene reagent. Iodobenzenediacetate was converted by using 2 equiv of TFOH to a highly reactive iodine reagent. Also, o-iodosylbenzoic acid provided a highly reactive iodine reagent. These hypervalent iodine reagents showed a high reactivity to aromatic and acetylenic substrates to give aryl and alkynyliodoniumu salts in high yields.2.High Reactivity of Hypervalent Iodine CompoundsThe high reactivity of the hypervalent iodine reagents was attributed to the high nucleofugacity of triflate group attached with iodine. The electron withdrawing groups on the aromatic ring increased the reactivity. The high reactivity of hypervalent compounds toward nucleophiles was derived from the high leaving ability of the phenyliodonio group.3.Synthesis of Novel Hypervalent CompoundsThe highly reactive hypervalent reagents developed in this research provided many novel hypervalent compounds, such as (p-phenylene) bisiodonium salts, alkynyliodonium salts, diaryliodonium salts, aryl-and alkynyliodonium salts with carboxy group, 1-arylbenzothiophenium salts, and the related derivatives, in addition to liquid-crystalline diacetylenes and benzyne precursors.