Enantioselective Organocatalyzed Cascade Dearomatizing Spirocycloaddition Reactions of Indole-Ynones

Org Lett. 2024 Oct 18;26(41):8713-8718. doi: 10.1021/acs.orglett.4c03015. Epub 2024 Oct 4.

Abstract

An intramolecular organocatalytic cascade dearomatizing spirocycloaddition reaction of indole-ynone compounds containing O-silyl-naphthol substituents has been developed with the use of a chiral bifunctional thiourea. This process was able to provide various structurally diverse polycyclic spiroindolines in high yields (up to 98%) with excellent stereoselectivities (>20:1 dr, up to 98% ee) involving the formation of carbonylvinylidene ortho-quinone methide intermediates.