Intramolecular Pyridone/Enyne Photocycloaddition: Partitioning of the [4 + 4] and [2 + 2] Pathways
作者:Svitlana Kulyk、William G. Dougherty、W. Scott Kassel、Michael J. Zdilla、Scott McN. Sieburth
DOI:10.1021/ol200390j
日期:2011.5.6
Intramolecular photocycloaddition (>290 nm) between a 1,3-enyne and a 2-pyridone is far more selective than the intermolecular version; a three-atom linkage both controls regiochemistry and separates the [2 + 2] and [4 + 4] pathways. All four head-to-head, head-to-tail, tail-to-head, and tail-to-tail tetherings have been investigated. Linkage via the ene of the enyne leads to [2 + 2] products regardless
1,3-烯炔和2-吡啶酮之间的分子内光环加成(> 290 nm)比分子间形式具有更高的选择性。三原子链接既控制区域化学作用,又分离[2 + 2]和[4 + 4]途径。已对所有四个头对头,头对尾,尾对头和尾对尾的系链进行了研究。连杆经由所述烯炔引线的烯[2 + 2]的产品,无论烯烃的几何形状,而连杆通过在[4 + 4]的cycloadducts炔结果。[4 + 4]环加成反应的桥联1,2,5-环辛三烯产物不稳定,并会随后发生[2 + 2]二聚反应。