Iodo-Annulations of N -Benzyl-propiolamides Leading To Azaspiro[5.5]undecatrienones or Benzo[ c ]azepinones.

Iodine-mediated oxidative annulations of N -benzyl-propiolamides are disclosed for the first time, providing either azaspiro[5.5]undecatrienones via dearomative ipso -annulation or benzo[ c ]azepinones through ortho -annulation. The selective construction of the aforementioned products is based on the ceric ammonium nitrate (CAN)-promoted divergent reactivity of the propiolamide, directed by the substituents on the phenyl ring of the N -benzyl group. [ABSTRACT FROM AUTHOR]