Asymmetric synthesis of chiral trifluoromethylated heliotridane via highly catalytic asymmetric Friedel-Crafts alkylation with p-trifluoromethylatei acrylates and pyrroles

摘要

Chiral Ph-dbfox (Ph-dbfox = (R,R)-4,6-dibenzofurandiyl-2,2'-bis(4-phenyloxazoline))/Zn(NTf2)2 catalyzed enantioselective Friedel-Crafts reactions of β-CF3 acrylates with pyrroles and indoles have been investigated, which afforded the corresponding chiral trifluoromethyl pyrrole and indole derivatives in high yields (90-99%) with a range of 66-99% ee values. With the aid of the chiral adduct of the asymmetric Friedel-Crafts reaction, the chiral trifluoromethylated heliotridane has been successfully constructed in good total yield.