Phenolate-Induced N-O Bond Formation versus TiemannType Rearrangement for the Synthesis of 3-Aminobenzisoxazoles and 2-Aminobenzoxazoles.

ABSTRACT: A novel oxadiazolone-based method for the synthesis of 3-aminobenzisoxazoles by N-O bond formation and of 2-aminobenzoxazoles through a Tiemann-type rearrangement has been developed. The synthesis of these two pharmaceutically relevant heterocycles was realized by an unexplored retrosynthetic disconnection using a cyclic nitrenoid precursor-based strategy. The selective formation of the two isomers was significantly influenced by steric and electronic effects of substituents. However, tetrabutylammonium chloride (TBACl) efficiently promoted the Tiemann-type rearrangement over N-O bond formation. Control experiments indicate that deprotonation of the phenol induces both rearrangements.

SUBMITTER: Hufnagel B 

PROVIDER: S-EPMC9789021 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature