Toward understanding the regioselectivity of the one‐pot reaction of phenylene diamines with aldehydes and cyclopentadiene (Povarov reaction). Combined experimental and theoretical approaches

Abstract

Three-component acid-catalyzed cyclocondensation of isomeric phenylenediamines with aldehydes and cyclopentadiene (CPD) was studied. In the M06-2X//B3LYP/6-311 + G(d,p) + IEFPCM(SMD) approximation, a quantum chemical model was developed, energies of the PES stationary points were determined, and activation barriers were found for the CPD addition to the protonated Schiff base (rate-limiting step) and for electrophilic carbocation cyclization to give endo, endo (syn)-or endo, exo (anti)-cyclopentene-annulated octahydropyridoquinoline-and octahydrophenanthroline-based cycloadducts.