A facile and atom‐efficient route via a new aqueous synthetic protocol for the greener and more efficient preparation of 3‐phenylpyrrolo[1,2‐a]pyrazine and 3‐phenylpyrazino[1,2‐a]indole by the one‐pot, three‐component method under mild reaction conditions is developed with substituted phenacyl bromides, aqueous ammonium hydroxide, and the corresponding 1H‐pyrrole‐2‐carbaldehyde and 1H‐indole‐2‐carbaldehyde. A reaction cascade consisting of N‐alkylation, imine formation, and annulation by condensation produces a sequence of three C−N bonds.