Herein, we report a metal/additive-free protocol for the activation of nitrile towards nucleophilic addition and subsequent annulation under an aqueous medium for the first time. The protocol divulges an efficient and atom economical route for the construction of diverse aminated isoquinolines. Differently substituted primary as well as secondary amines underwent the reaction in a highly regioselective manner. The reaction is operationally simple, shows high functional group tolerance and easier modification of well-known drugs, and can be successfully extended to gram-scale synthesis.