In the zone: Pd‐catalyzedoxidativecross‐coupling of N‐tosylhydrazones with allylic alcohols leads to CC bond formation. A palladium–carbene migratory insertion is proposed to play the key role in this transformation. The reaction proceeds with readily available starting materials to afford substituted alkenes in a highly stereoselective manner (see scheme).
The first catalytic enantioselectivesynthesis of 5,6-dihydro-4H-1,2-oxazines bearing an oxygen-containing quaternarystereogeniccenter has been developed through iodoetherification of γ,δ-unsaturated oximes. This operationally straightforward reaction is catalyzed by Cinchona alkaloids-based bifunctional tertiary aminothiourea derivatives and furnishes the products generally in good to excellent
通过γ,δ-不饱和肟的碘醚化,已经开发出了一个带有含氧季立体中心的5,6-二氢-4 H -1,2-恶嗪的第一催化对映选择性合成。该操作简单的反应被基于金鸡纳生物碱的双功能叔氨基硫脲衍生物催化,并通常以高至优异的收率和中等至高的对映选择性(高达97:3 er)提供产物。
Palladium-Catalyzed Cross-Coupling Reactions of Electron-Deficient Alkenes with<i>N</i>-Tosylhydrazones: Functional-Group-Controlled CC Bond Construction
作者:Huanfeng Jiang、Wei Fu、Huoji Chen
DOI:10.1002/chem.201202051
日期:2012.9.17
palladium‐catalyzed cross‐coupling reaction of electron‐deficient alkenes with N‐tosylhydrazones, which affords diverse CC bonds resulting from the functional‐group‐controlled effect, is reported (see scheme). These cascade transformations present remarkable stereoselectivity and a high synthetic potential. The presence of water substantially promotes both reaction routes.
A diastereo- and enantioselective synthesis of boron-containing cyclobutanols is reported. We exploit an enantioselective borylcupration to generate a chiral benzylic copper intermediate that is intercepted with a proximally tethered ketone. The scaffolds contain an all-carbon quaternary center with a modular boronate moiety which allows access to a variety of synthetically valuable functional groups