Copper-Catalyzed Trifluoromethylation of Internal Olefinic CH Bonds: Efficient Routes to Trifluoromethylated Tetrasubstituted Olefins and N-Heterocycles
olefins has been a challenging task in organic synthesis. Efficient CuII‐catalyzed trifluoromethylation of internal olefins, that is, α‐oxoketene dithioacetals, has been achieved by using Cu(OH)2 as a catalyst and TMSCF3 as a trifluoromethylating reagent. The push–pull effect from the polarized olefin substrates facilitates the internal olefinic CHtrifluoromethylation. Cyclic and acyclic dithioalkyl α‐oxoketene
Copper-Catalyzed Ring-Expansion/Thiolactonization<i>via</i>Azidation of Internal Olefinic C-H Bond under Mild Conditions
作者:Tenglong Guo、Quanbin Jiang、Zhengkun Yu
DOI:10.1002/adsc.201600675
日期:2016.11.3
A copper(I)‐catalyzed, (diacetoxyiodo)benzene [PhI(OAc)2]‐mediated ring‐expansion/thiolactonization of α‐oxo ketene dithioacetals was efficiently realized via azidation of the internal olefinic C−H bond with sodium azide under mild conditions. Sequential amination, ring‐expansion rearrangement, and thiolactonization occurred to form aminated thiolactones in the presence of acetic anhydride as the additive
The palladium‐catalyzed oxidative Heck‐type allylation of β,β‐disubstituted enones, i.e., α‐oxoketene dithioacetals, was efficiently realized with allyl carbonates, providing a concise route to highly functionalized dienes. The present synthetic methodology utilizes the substrate activation strategy to activate the CH bond of β,β‐disubstituted enones by introduction of a 1,2‐dithiolane functionality