The Tetraethylphosphorodiamidate (OP(O)(NEt2)2) Directed Metalation Group (DMG). Directed ortho and Lateral Metalation and the Phospha Anionic Fries Rearrangement.

Abstract

We report on the tetraethylphosphorodiamidate (-OP(O)(NEt2)2) group as an effective directed metalation group (DMG). Lithiation-electrophile quench of 1 provides a general synthesis of ortho-substituted aryl and naphthyl phosphorodiamidates 4-8. We also describe the phospha anionic ortho-Fries (AoF) rearrangement of the phosphorodiamidates 1a,1b → 2 or 3 and its vinylogous counterpart to the ortho-tolyl phosphorodiamidates 5b → 13. Intermolecular competition experiments demonstrate the approximately equal DMG strength of the -OP(O)(NEt2)2 and the most powerful OCONEt2 groups.