An Expedient Variant of Heck Reaction of Alkenyl Nonaflates: Homogeneous Ligand-Free Palladium Catalysis at Room Temperature
作者:Michael A. K. Vogel、Christian B. W. Stark、Ilya M. Lyapkalo
DOI:10.1002/adsc.200600388
日期:2007.5.7
represents a remarkably robust, active and efficient catalyticsystem generally applicable to the coupling with a broad range of terminal olefins including non-activated ones under ambient conditions. It features insensitivity towards atmospheric oxygen and moisture, furnishing uniformly high yields of the anticipated coupling products without the necessity to purify commercial reagents and solvents.
A Straightforward Synthesis of Alkenyl Nonaflates from Carbonyl Compounds Using Nonafluorobutane-1-sulfonyl Fluoride in Combination with Phosphazene Bases
作者:Ilya Lyapkalo、Michael Vogel、Christian Stark
DOI:10.1055/s-2007-991084
日期:——
nonafluorobutane-1-sulfonyl fluoride furnishes the corresponding alkenyl nonaflates. The new general method provides high yields of alkenyl nonaflates from aldehydes and cyclic ketones. However, it is not applicable to acyclicketones whose nonaflate derivatives undergo fast E2 elimination to give alkynes. Successful synthesis of nonaflates from aldehydes requires carefully controlled reaction conditions to avoid
在内部淬灭剂九氟丁烷-1-磺酰氟的存在下,羰基化合物与磷腈碱的 α-去质子化提供相应的烯基九氟甲磺酸酯。新的通用方法从醛和环酮中提供了高产率的烯基壬二酸酯。然而,它不适用于非环酮,其九氟甲磺酸酯衍生物经过快速 E2 消除得到炔烃。由醛成功合成九氟甲磺酸酯需要仔细控制反应条件,以避免随后消除为炔烃。动力学控制能够实现高区域选择性,有利于衍生自环酮的最少取代的九氟甲磺酸酯区域异构体和衍生自醛的烯基九氟甲磺酸酯的适度 Z 选择性。