Synthesis of heterocycles by iodocyclization and controlling of aromatization

碘代环化反应是构建功能化分子结构的最有吸引力的方法之一。该反应不仅可以产生环骨架，还可以产生碘官能度用于进一步转化。此外，碘化试剂相对便宜，是实现环境友好反应的理想选择。我开发了一种基于试剂控制氧化芳构化的碘环化新方法。该策略利用了碘作为碘化剂和氧化剂的双重性质。所揭示的方法实现了“产物转换“，并增强了合成途径向吡唑、异恶唑和吡咯的灵活性。此外，环化产物的碘代部分可以产生进一步的多样性。该方法在合成伐地考昔及其2，5-二氢类似物中得到了证实。幸运的是，在制备过程中，开发了一种有效的方法，通过串联迁移-羰基烷氧基化邻异氰苯基缩醛的苯并恶唑。

Iodocyclization is one of the most attractive methods for the construction of functionalized molecular architecture. This reaction can create not only the ring skeleton but also the iodo functionality for further transformation. In addition, iodinating reagents are relatively inexpensive and are ideal for achieving environmentally friendly reactions. I have developed a new method of iodocyclization based on reagent-controlled oxidative aromatization. This strategy takes advantage of the dual nature of iodine as both an iodinating and an oxidizing agent. The revealed approach enabled "product switch"and enhanced the flexibility of the synthetic pathway toward pyrazoles, isoxazoles, and pyrolles. In addition, the iodo moiety of the cyclized product could create further diversity. The utility of this methodology was demonstrated in the synthesis of valdecoxib and its 2, 5-dihydro analogs. During the elaborating process, fortunately, an efficient approach to benzoxazoles via tandem migration-carboalkoxylation of o-isocyanophenyl acetals has been developed.