Construction of CF3-Containing Tetrahydropyrano[3,2-b]indoles through DMAP-Catalyzed [4+1]/[3+3] Domino Sequential Annulation

A [4+1]/[3+3] domino sequential annulation reaction of o-aminotrifluoroacetophenone derivatives and β′-acetoxy allenoates enabled by DMAP has been reported. A variety of CF3-containing tetrahydropyrano[3,2-b]indoles were obtained as a single diastereomer in high yields (≤98%) under mild conditions. The reaction can build one C–N bond, one C–C bond, and one C–O bond sequentially in a single step. The synthetic utility was demonstrated with gram-scale reactions and various transformations of the products.