Enantioselective Synthesis of 3,4-Dihydroisoquinolin-1(2<i>H</i>)-ones by Nickel-Catalyzed Denitrogenative Annulation of 1,2,3-Benzotriazin-4(3<i>H</i>)-ones with Allenes
A denitrogenative annulationreaction of 1,2,3-benzotriazin-4(3H)-ones with allenes catalyzed by a nickel-phosphine complex to produce a variety of substituted 3,4-dihydroisoquinolin-1(2H)-ones in a regioselective manner is described. A highly enantioselective version, as well as structural evidence for the mechanistic course of this reaction, is also presented.
1,2,3-Benzotriazin-4(3H)-ones and 1,2,3,4-benzothiatriazine 1,1(2H)-dioxide reacted with isocyanides in the presence of a palladium catalyst to give 3-(imino)isoindolin-1-ones and 3-(imino)thiaisoindoline 1,1-dioxides, respectively, in high yield. An intermediate azapalladacycle was generated through denitrogenation of the triazine moiety, and an isocyanide was incorporated therein.