Synthesis of Alkenylboronates from <i>N</i>-Tosylhydrazones through Palladium-Catalyzed Carbene Migratory Insertion
作者:Yifan Ping、Rui Wang、Qianyue Wang、Taiwei Chang、Jingfeng Huo、Ming Lei、Jianbo Wang
DOI:10.1021/jacs.1c02331
日期:2021.7.7
The palladium-catalyzed oxidative borylation reaction of N-tosylhydrazones has been developed. The reaction features mild conditions, broad substratescope, and good functional group tolerance. It thus represents a highly efficient and practical method for the synthesis of di-, tri-, and tetrasubstituted alkenylboronates from readily available N-tosylhydrazones. One-pot Suzuki coupling and other transformations
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).
NNNifty targets: In a straightforward copper‐mediated synthesis of 1,4‐disubstituted and 1,4,5‐trisubstituted 1,2,3‐triazoles, readily available aniline and N‐tosylhydrazone substrates underwent cyclization through CN and NN bond formation (see scheme; Piv=pivaloyl, Ts=p‐toluenesulfonyl). This method enables the preparation of 1,2,3‐triazoles with high efficiency under mild conditions without the
A general and expeditious approach for the copper mediated synthesis of multi‐functionalized dihydropyrazoles from N‐sulfonylhydrazones and sulfoxonium ylides has been achieved under aerobic oxidative conditions. The formal [4+1] cycloaddition reaction exhibits many notable features and can be easily scaled up to gram scale.
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.