Synthesis of highly substituted aniline and o-phenylenediamine derivatives containing various substitution patterns

The Diels-Alder reactions of a variety of 2H-pyran-2-ones 1 with alkynes 2 yielding highly substituted aniline and o-phenylenediamine derivatives 4 with novel (and in some cases known but very rare and useful) structural patterns are presented. The effect of substituents of both reactants on the reaction rates was investigated. The reactions were carried out under thermal conditions, as well as at high pressures.