Isomerization of Allyl Ethers Initiated by Lithium Diisopropylamide
摘要:
Lithium diisopropylamide (LDA) promotes virtually quantitative conversion of allylic ethers to (Z)-propenyl ethers. It was discovered that allylic ethers can be isomerized efficiently with very high stereoselectivity to (Z)-propenyl ethers by LDA in THF at room temperature. The reaction time for the conversion increases with more sterically hindered allylic ethers. Different amides were also compared with LDA for their ability to effect this isomerization.
Defluorinative Alkylation of Trifluoromethylbenzimidazoles Enabled by Spin-Center Shift: A Synergistic Photocatalysis/Thiol Catalysis Process with CO<sub>2</sub><sup>•–</sup>
direct single C(sp3)–F bond alkylation of trifluoromethylbenzimidazoles under a photoinduced thiol catalysis process. The CO2 radical anion (CO2•–) proved to be the most efficient single-electron reductant to realize such a transformation. The spin-center shift of the generated radical anion intermediate is the key step in realizing C–F bond activation under mild conditions with high efficiency.