An efficient selective reduction of aromatic azides to amines employing BF3•OEt2/NaI:: Synthesis of pyrrolobenzodiazepines

A selective and facile method for the reduction of aromatic azides to amines by employing borontrifluoride diethyl etherate and sodium iodide. This methodology has been applied towards the preparation of biologically important imine-containing pyrrolobenzodiazepines and their dilactams through intramolecular reductive-cyclization process. In this protocol the reagent systems are amenable for the generation of solution-phase combinatorial synthesis.