Regioselectivity and endo/exo selectivity in the cycloadditions of the phthalazinium dicyanomethanide 1,3-dipole with unsymmetrical alkene and alkyne dipolarophiles. Unexpected reversals of regiochemistry: a combined experimental and DFT theoretical study

The kinetic profile of phthalazinium-2-dicyanomethanide 1,3-dipole with 2π-dipolarophiles: U-shaped dipolarophilic activity and classic type II dipole behaviour. Reaction rates and DFT calculations