Atom-economical construction of tetracyclic [1,4]oxazepines involving intramolecular arylation of a 2-imidazoline moiety

Novel [1,4]oxazepines containing a fused imidazoline moiety were synthesized from 2-hydroxyphenyl imidazolines and bis-electrophilic aromatic substrates in a reaction involving sequential nucleophilic aromatic substitution steps and a Smiles rearrangement. A notable step was the remarkably facile, metal-free intramolecular N-arylation of the imidazoline moiety with a fluoro-, nitro- or chloroaromatic or heteroaromatic ring. The approach presented in this Letter not only details access to a new, medicinally relevant tetracyclic [1,4]oxazepine core but also extends the scope of imidazoline arylation chemistry.

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