Nucleophile Screening in Anion-Binding Reissert-Type Reactions of Quinolines with Chiral Tetrakis(triazole) Catalysts

A nucleophile screening for the organocatalyzed enantioselective Reissert-type dearomatization of quinoline derivatives using chiral triazoles as anion-binding catalysts was realized. Our recently reported helical tetrakis(triazole) catalysts (TetraTri) have proven to be highly active in this type of reactions, however the methods were limited to nucleophiles with a N value of 10 according to the Mayr's nucleophilicity scale. In this study, different carbon-nucleophiles of varied nucleophilicity N-values were explored, allowing the identification of potential novel reaction partners with N >5 such as ketene thioacetals. Thus, a number of chiral 1,2-dihydroisoquinoline-thioesters with an enantioselectivity up to 92:8 er. were synthetized, which could easily be transformed into a more valuable amide derivative.