The potential of phosphites as nucleophiles for the synthesis of chiral chromene derivatives has been overlooked in the literature. Herein, we report a highly promising approach via asymmetric organocatalyzed phospha-Michael addition to iminochromenes, using a bifunctional squaramide. Our optimized protocol provides very good reactivity, affording yields of up to 95% and excellent enantioselectivity, with chiral products exhibiting an outstanding enantiomeric excess of up to 98%.
Asymmetric Organocatalyzed Phospha-Michael Addition to Iminochromenes
23 May 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.