Rhodium(iii)-catalyzed [3 + 3] annulation reactions of N-nitrosoanilines and cyclopropenones: an approach to functionalized 4-quinolones†
We report Rh(III)-catalyzed [3 + 3] annulation reactions for the preparation of functionalized 4-quinolones from N-nitrosoanilines and cyclopropenones. This reaction allows C–C bond cleavage and the construction of C–C and C–N bonds via N-nitroso-directed C–H activation. Good regioselectivity is achieved by using unsymmetrical meta-substituted N-nitrosoanilines. With this method, a variety of 4-quinolone derivatives were prepared in moderate to good yields under mild conditions.