Dearomatization of 2,3-Disubstituted Indoles via 1,8-Addition of Propargylic (Aza)--Quinone Methides.

Dearomatization of indole is a useful strategy to access indolimines: a motif widely exists in biologically active molecules and natural products. Herein, an efficient method for the dearomatization of 2,3-disubstituted indoles to generate diverse indolimines with tetrasubstituted allenes is described. This work accomplishes dearomatization of 2,3-disubstituted indoles through 1,8-addition of (aza)--quinone methides, which are generated in situ from propargylic alcohols.