THEORETICAL PREDICTIONS OF ACTIVATION-ENERGIES FOR 1,2-HYDROGEN SHIFTS IN SINGLET CARBENES

Activation energies for 1,2-hydrogen shifts of substituted methylcarbenes are predicted using MP4/6-311G** energies calculated on MP2/6-31G* optimized geometries. An excellent linear free energy correlation is observed between predicted activation energies and the σR° values of the α-substituents. Activation barriers for the 1,2-hydrogen shift of methylcarbene, methylchlorocarbene, cis- and trans-methylhydroxycarbene, cis- and trans-methylmethoxycarbene, trans-methylvinylcarbene, and allylcarbene are predicted and compared with experimental values, when available. © 1990 American Chemical Society.