Ds. Black et al., NITRONES AND OXAZIRIDINES .46. FORMATION OF PYRROLO[3,2,1-IJ]QUINOLINES BY INTRAMOLECULAR NITRONE CYCLOADDITION, Australian Journal of Chemistry, 46(6), 1993, pp. 843-862
Intramolecular 1,3-dipolar cycloaddition occurs between nitrones deriv
ed from indole-7-carbaldehydes and adjacent allylic substituents on th
e indole nitrogen atoms. The resulting pyrroloquinoline derivatives (4
a-i) have been characterized fully. A range of other potential precurs
ors to cycloaddition reactions have been synthesized, but cyclization
Sequences have not been completed.