Multicomponent domino [4+2]/[3+2] cycloadditions of nitroheteroaromatics: an efficient synthesis of fused nitrogenated polycycles

Activation by high pressure allows 3-nitroindole and 3-nitropyrrole derivatives to behave as electron-poor heterodienes in multicomponent domino 4+2]/3+2] cycloaddition processes. The primary 4+2] inverse demand cycloaddition appears to be completely endo selective, while the subsequent 3+2] process shows a total facial selectivity, setting the stereochemistry at ring junction, and an endo/exo selectivity depending on the nature of the heterocycle. In two operations, a polycyclic diamine featuring a quaternary center at ring junction is efficiently generated.