Abstract
Two types of reaction are important for the photolysis of the phosphinic azides Ar2P(O)N3(Ar = mesityl or 2,4,6-triisopropylphenyl) in MeCN–MeOH: Curtius-like rearrangement, giving ArP(O)(OMe)NHAr, and nitrene insertion into a C–H bond of an ortho substituent (Me or CHMe2), giving a dihydrobenzazaphosphole oxide 11 or 12. The behaviour of ButArP(O)N3(Ar = mesityl) is similar except that two rearrangement products are formed (But or Ar migration; ratio 6:1). Extensive intramolecular insertion is unprecedented for photochemically-generated phosphorus(V) nitrenes. The exceptional behaviour of the present azides probably owes much to steric congestion. It may discourage rearrangement (Ar migration), relative to other phosphinic azides, so more nitrene is made available for insertion reactions; and it may encourage intramolecular reaction, relative to phosphoryl azides, by shielding the nitrene from external molecules (solvent) while ensuring that an internal C–H bond is held in close proximity.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.