Methodology Development for the Electrophilic Aromatic Amination of Secondary Amides

Abstract

The intramolecular electrophilic aromatic amination of secondary amides was developed. Secondary N-methoxy and N-p-methoxyphenyl amides were cyclized to oxindoles by triflic anhydride mediated electrophilic activation and subsequent oxidation with a pyridine N-oxide derivative. The electrophilic nitrogen species for the N-methoxy amide was isolated and characterized. Aryl tethered 2-amidopyridine- and 2-amidopyrimidine N-oxides were additionally discovered to be synthetically valuable sources of electrophilic nitrogen under mild conditions following a simple activation protocol of triflic anhydride and tertiary amine base.