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

Abstract

In this paper, I2-mediated oxidative annulations of N-benzyl-propiolamides has been 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 aforementioned products is based on the ceric ammonium nitrate (CAN)-promoted divergent reactivity of the propiolamide, directed by the substitution on phenyl ring of N-Benzyl group