New bimolecular mechanistic pathway for 1,3-hydrogen shift in allenamide and allene system: A theoretical prediction

► Stepwise bimolecular mechanism for allenamide isomerization is more favorable than the concerted mechanism. ► Carboxylic acid catalyzes the isomerization process through a relay mechanism. ► Stereoselectivity can be predicted correctly through bimolecular mechanism. ► Regioselectivity can be predicted correctly through bimolecular mechanism. ► Self catalysis bimolecular mechanism is applicable for allene isomerization.