Reactions of HDDA Benzynes with C,N-Diarylimines (ArCH=NAr').
o-Benzynes can be utilized to construct heterocyclic motifs using various nucleophilic and cycloaddition trapping reactions. Acridines have been synthesized by capture of C,N-diarylimines with benzynes generated by classical methods (i.e., from ortho-elimination of precursor arene compounds), although in poor yields. We report here that these imines can be trapped by benzynes generated by the hexadehydro-Diels-Alder (HDDA) reaction in an efficient manner to produce 1,4-dihydroacridine products. These dihydroacridines were subsequently aromatized using MnO2 to provide structurally complex acridines.
['Arora|Sahil|S|', 'Sneddon|Dorian S|DS|', 'Hoye|Thomas R|TR|']
acridines dihydroacridines HDDA-benzynes azoquinone methides benzazetidines