HSAB principle: Applications of its global and local forms in organic chemistry

The hard and soft acids and bases (HSAB) principle, both in its local and global versions, is applied, to a series of chemical reactions, including eleminations and substitutions, Diels–Alder cycloadditions, enolate–ion alkylation, and 1,3-dipolar additions. It will be shown that this principle, in the different resolutions, provides a powerful tool in the study of regioselectivity problems in organic chemistry.