In(OTf)3-catalyzed N-α phosphonylation of N,O-acetals with triethyl phosphite

Abstract

A practical approach to α-aminophosphonates has been developed through an In(OTf)₃-catalyzed N-α phosphonylation of N,O-acetals with triethyl phosphite 7. Indoline and isoindoline N,O-acetals 6a–6j and 9a–9j and chain N,O-acetals 11a–11p were subjected to a Lewis acid catalyzed N-α phosphonylation process. As a result, the desired α-aminophosphonates 8a–8j, 10a–10j and 12a–12p were obtained in moderate to good yields.