Abstract <p>The review systemizes literature data on the synthesis, chemical transformations, and application of Bett bases over a period of 2004 to 2025. Various aspects of the classical Betti reaction, including conditions, catalysts, solvents, selectivity, mechanism, and compliance with the “green” chemistry principles, are con­sidered in detail. The effects of different catalysts on the yield, reaction time, and selectivity are compared. Particular attention is given to the transformations of Betti bases, especially oxidative cyclization reactions, rearrangements, reactions with nucleophilic and electrophilic reagents, as well as reactions involving <i>o</i>-quinone methides generated therefrom. The stereochemical output of the reactions with chiral substrates is analyzed with respect to chiral auxiliary, substituent nature, catalyst, and solvent. Examples of application of Betti bases in both fundamental research (as ligands in asymmetric catalysis) and applied fields, such as medicinal chemistry and pharmacology, are given.</p>