Enantioselective synthesis of coumarins catalyzed by an isosteviol-derived tertiary amine-squaramide catalyst

A newly tertiary amine-squaramide organocatalyst has been successfully developed and applied into the asymmetric Michael addition of 4-hydroxycoumarin to beta, gamma-unsaturated alpha-ketoesters. The catalyst system performed well with a low catalyst loading of 1 mol% under mild reaction conditions. A series of coumarin derivatives were obtained in good to high yields (up to 97%) with high enantioselectivities (up to 96% ee).

Automated summary

A newly developed tertiary amine-squaramide organocatalyst has shown excellent performance in the asymmetric Michael addition reaction, achieving high yields and enantioselectivities with low catalyst loading. This catalyst system has the potential for efficient synthesis of coumarin derivatives in organic chemistry applications.