Chiral phosphoric acid-catalyzed Friedel-Crafts reaction of 2,5-disubstituted and 2-monosubstituted pyrroles with isoindolinone-derived ketimines

Org Biomol Chem. 2023 Apr 26;21(16):3381-3387. doi: 10.1039/d3ob00326d.

Abstract

The enantioselective reaction between 2,5-disubstituted pyrroles and diaryl-ketimines, generated in situ from isoindolinone-derived alcohols, is described. Pyrrole derivatives possessing a congested tetrasubstituted stereogenic center at the β-(C3) position are generally obtained in high yields and enantioselectivities. The transformation can be extended to 2-monosubstituted pyrroles, generating chiral α-(C5) functionalized pyrrole products. Control experiments were conducted in order to elucidate the origin of the low enantioselectivities observed in some of the products.