Generation and Trapping of Alkene Radical Cations under Nonoxidizing Conditions: Formation of Six-Membered Rings by <i>E</i><i>xo</i>- and <i>E</i><i>ndo</i>-Mode Cyclizations
作者:David Crich、Santhosh Neelamkavil
DOI:10.1021/ol026204x
日期:2002.7.1
[reaction: see text] It is demonstrated that alkene radical cations generated by the radical ionic fragmentation of beta-(phosphatoxy)alkyl radicals undergo efficient nucleophilic capture by amines in either the 6-exo or 6-endo modes, leading to six-membered nitrogen heterocycles. Suitable placement of an alkene enables the juxtaposition of a radical cyclization resulting in the formation of both the
[反应:参见正文]已证明,由β-(磷酸氧基)烷基自由基的离子断裂产生的烯烃自由基阳离子在6-exo或6-endo模式下被胺有效地亲核捕获,从而导致六元模式氮杂环。烯烃的适当放置能够使自由基环化并置,导致形成吲哚并立啶和1-氮杂双环[3.2.1]辛烷骨架。