On-Demand Generation and Use in Continuous Synthesis of the Ambiphilic Nitrogen Source Chloramine

Herein, we demonstrate the on-demand
synthesis of chloramine from
aqueous ammonia and sodium hypochlorite solutions, and its subsequent
utilization as an ambiphilic nitrogen source in continuous-flow synthesis.
Despite its advantages in cost and atom economy, chloramine has not
seen widespread use in batch synthesis due to its unstable and hazardous
nature. Continuous-flow chemistry, however, provides an excellent
platform for generating and handling chloramine in a safe, reliable,
and inexpensive manner. Unsaturated aldehydes are converted to valuable
aziridines and nitriles, and thioethers are converted to sulfoxides,
in moderate to good yields and exceedingly short reaction times. In
this telescoped process, chloramine is generated in situ and immediately used, providing safe and efficient conditions for
reaction scale-up while mitigating the issue of its decomposition
over time.