1,3-Dipolar character of six-membered aromatic rings. Part 38. FMO treatment of peri-, site, regio, and stereo-selectivity, and relative reaction rates of cycloaddition reactions

Abstract

The kinetic rates and peri-, site, regio-, and stereo-selectivity of the reactions of variously 1-substituted 3-oxidopyridiniums have been correlated by FMO theory. Regioselectivity is well explained by the standard perturbation treatment, but for correlation of the relative rates it is necessary to use the simpler equation of Sustmann. For the most part, stereoselectivity is well explained by a simple monopole repulsion treatment. Peri- and site selectivity are also discussed and are well correlated for reactions of dienes but not for fulvenes.