We have described a facile, microwave-assisted, catalyst-free and solvent-free approach to 2H-indazoles and further developed a robust tandem one-pot metal-free strategy for C–C bond formation at the C-3 position of 2H-indazoles leading to a unique class of aza-γ-carboline alkaloid analogues. This straightforward expedient synthesis constitutes an interesting alternative to the existing conventional transition metal catalyzed reactions.