Photocatalytic Spirocyclization of 2-Alk-ω-enyl-Substituted Cycloalkane-1,3-diones
作者:Thorsten Bach、Johannes Hofer、Franziska Pecho
DOI:10.1055/a-2004-3771
日期:——
visible light, various cyclic 2-alk-4-enyl-substituted 1,3-diketones undergo an intramolecular endo-addition (m = 1) onto the double bond resulting in spirocyclic products (11 examples, 62–92% yield). Both an organic (TXT: thioxanthone, 20 mol%) and an organometallic Ir-based photocatalyst (5 mol%) promote the reaction. Addition of triisopropylthiophenol is required to secure high yields. The spirocyclization
当用可见光照射时,各种环状 2-alk-4-enyl-取代的 1,3-二酮在双键上进行分子内内加成 ( m = 1),产生螺环产物(11 个例子,62-92% 产率). 有机物(TXT:噻吨酮,20 mol%)和有机金属 Ir 基光催化剂(5 mol%)均可促进反应。需要添加三异丙基苯硫酚以确保高产率。2-alk-5-enyl-取代底物 (m = 2) 的螺环化提供了七元内环化和六元外环化产物的混合物。