Phospha-Michael Additions to Activated Internal Alkenes: Steric and Electronic Effects
作者:Heather K. Lenker、Marcia E. Richard、Kyle P. Reese、Anthony F. Carter、Jason D. Zawisky、Eric F. Winter、Timothy W. Bergeron、Krysta S. Guydon、Robert A. Stockland
DOI:10.1021/jo202183u
日期:2012.2.3
The addition of P(O)–H bonds to internal alkenes has been accomplished under solvent-free conditions without the addition of a catalyst or radical initiator. Using a prototypical secondary phosphine oxide, a range of substrates including cinnamates, crotonates, coumarins, sulfones, and chalcones were successfully functionalized. Highly activated acceptors such as isopropylidenemalononitrile and ethyl
在无溶剂条件下,无需添加催化剂或自由基引发剂即可将P(O)–H键添加至内部烯烃。使用典型的仲膦氧化物,可以成功地官能化包括肉桂酸酯,巴豆酸酯,香豆素,砜和查耳酮的多种底物。在室温下将试剂简单研磨后,高度活化的受体(如异丙基亚甲基丙二腈和2-氰基-3-甲基-2-丁烯酸乙酯)就发生了磷-迈克尔反应,而活化程度较低的底物(如肉桂酸乙酯和巴豆酸甲酯)则需要加热(> 150℃)在微波反应器中,以实现起始烯烃的大量消耗。对于后面的烯烃,