Cycloaddition of nitrile oxides to aza-analogues of phenanthrene

Article abstract of DOI:10.1016/S0040-4020(98)00556-0

Mesitonitrile oxide, but not benzonitrile oxide, adds to aza-analogues of phenanthrene to give low yields of monocycloadducts. Only phenanthridine reacts with the two nitrile oxides affording phenanthridinone. 4,7- phenanthroline also gives some other minor products among which the bisadduct to a pyridine ring was isolated. The reactivity of aza-analogues under examination is discussed in terms of FMO approximation.