Kuwano Satoru, Kikushima Jun, Nakada Takaaki, Sase Shohei, Goto Kei
Department of Chemistry, School of Science, Institute of Science Tokyo, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan.
Chem Asian J. 2025 Jul;20(14):e202500347. doi: 10.1002/asia.202500347. Epub 2025 Apr 14.
Although cascade cyclization of polyenes has advanced remarkably, most reported examples are limited to carbon- or oxygen-terminating groups, with nitrogen-terminating cyclizations remaining rare. In this work, we developed a cascade cyclization of polyenes with N-terminating groups, initiated by an isolable selenenyl iodide (RSeI) bearing a cavity-shaped substituent. Acid-labile substrates were successfully employed in the cascade cyclization. Compared with commonly used organoselenium reagents, a selenenyl iodide, characterized by its unique soft electrophilic nature, proved to be the most effective in promoting the cascade reaction. Furthermore, the stabilizing effect of the cavity-shaped substituent enabled the isolation of a selenenic acid (RSeOH), which was generated via oxidative β-selenoxide elimination from the cyclized product during its derivatization to an olefin, as a stable compound. We also developed a method for regenerating the starting selenenyl iodide from the selenenic acid. The reusability of the selenenyl iodide renders the series of molecular transformations environmentally benign by reducing unwanted organoselenium waste.
尽管多烯的串联环化反应已经取得了显著进展，但大多数已报道的例子仅限于碳端基或氧端基，氮端基的环化反应仍然很少见。在这项工作中，我们开发了一种带有氮端基的多烯串联环化反应，该反应由带有腔状取代基的可分离的硒基碘（RSeI）引发。对酸不稳定的底物成功地应用于串联环化反应中。与常用的有机硒试剂相比，具有独特软亲电性质的硒基碘被证明是促进串联反应最有效的试剂。此外，腔状取代基的稳定作用使得在环化产物衍生化为烯烃的过程中，通过氧化β-硒氧化物消除反应生成的硒酸（RSeOH）能够作为一种稳定的化合物被分离出来。我们还开发了一种从硒酸再生起始硒基碘的方法。硒基碘的可重复使用性通过减少不必要的有机硒废物，使这一系列分子转化对环境友好。
