Phosphine-Catalyzed Domino Annulation of γ‑Vinyl Allenoates: Synthesis of Tetrahydrofuro[3,2‑c]quinoline Derivatives

A novel phosphine-catalyzed domino annulation reaction of γ-vinyl allenoates and o-aminotrifluoacetophenones for the construction of terahydrofuro­[3,2-c]­quinoline derivatives has been developed. In this domino reaction, two kinds of terahydrofuro­[3,2-c]­quinoline compounds containing CF3 groups were obtained with good yields under mild conditions, three new C–N, C–C, and C–O bonds can be built in one step, and the reaction selectivity is achieved by adjusting the reaction conditions. Furthermore, preliminary studies on an asymmetric variant of this reaction proceeded with moderate enantioselectivity.