A direct route to branched N-allylpyrimidine analogues is herein reported via the highly regio- and enantioselective asymmetricallylation of pyrimidines with racemic allylic carbonates. With [Rh(COD)Cl]2/chiral diphosphine as the catalyst, a range of chiral pyrimidine acyclic nucleosides could be obtained under neutral conditions in good yields (up to 95% yield) with high levels of regio- and enantioselectivities
Co‐catalyzedallylic substitution reactions have received little attention, arguably because of the lack of any known advantage of Co catalysis over either Rh or Ir catalysis. Described here is a general and regioselective Co‐catalyzedallylicalkylation using an in situ catalyst activation by organophotoredox catalysis. This noble‐metal‐free catalytic system exhibits unprecedentedly high reactivities
enantioselective C‐allylations of isoxazolinones. These occur with high regioselectivity in favor of the linear allylation products, although Ir phosphoramidite catalysts were used, which commonly results in branched isomers. Our studies suggest that this outcome is the result of a reaction cascade via an initial regio‐ and enantioselective N‐allylation to provide a branched allyl intermediate, followed
An efficient Ru-catalyzed regioselective allylictrifluoromethylthiolation reaction of allylic carbonates was developed. The linear allylictrifluoromethylthioethers were obtained in 52–91% yields. Mechanistic investigation revealed that this reaction proceeds via a double allylictrifluoromethylthiolation sequence.
Asymmetric Redox Allylic Alkylation to Access 3,3′‐Disubstituted Oxindoles Enabled by Ni/NHC Cooperative Catalysis
作者:Tao Fan、Jin Song、Liu‐Zhu Gong
DOI:10.1002/anie.202201678
日期:2022.5.23
Chiral N-heterocyclic carbene and nickel cooperative catalysis enables asymmetric redox allylicalkylation to access 3,3′-disubstituted oxindoles with high enantioselectivity.