Thermodynamic Evaluation of Halogen Abstracting Abilities of Diazaphosphinyl Radicals.

Halogen atom transfer (XAT) is a pivotal strategy for generating carbon-centered radicals in organic chemistry, yet current methodologies often rely on toxic tin-based reagents or inefficient organosilanes. This study explores diazaphosphinyl (N-heterocyclic phosphinyl, NHP•) radicals as new halogen abstractors, leveraging their nucleophilic and halophilic properties. We synthesized a series of NHP-X (X = Cl or Br) compounds, systematically determining their P-X bond energies and related redox potentials. Thermodynamic analysis reveals that NHP• are good halogen abstractors, which was validated experimentally, highlighting their potential application in sustainable XAT processes.