Scalable, transition-metal-free direct oxime o-arylation: Rapid access to o-arylhydroxylamines and substituted benzo[b]furans

O-Aryloximes, generated from readily available and inexpensive oximes through transition-metal-free O-arylation, can either be hydrolyzed to O-arylhydroxylamines or conveniently converted to structurally diverse benzo[b]furans through an environmentally benign, one-pot [3,3]-sigmatropic rearrangement/cyclization sequence. A scalable, transition-metal-free (TM-free) direct O-arylation of ketone oximes with a wide range of diaryliodonium salts has been developed. More than two dozen O-arylated oximes have been prepared in good to excellent yields at ambient temperature and were converted to the corresponding substituted benzo[b]furans through a [3,3]-sigmatropic rearrangement/cyclization sequence. Overall, this operationally simple, environmentally benign, and protecting-group-free approach, including a one-pot variant, allows rapid and convenient synthetic access to substituted benzo[b]furans (see scheme).