This review examines current trends in the use of readily accessible acyclic enaminodiones in the synthesis of heterocyclic structures, including medicinal and natural compounds. Enaminodiones are latent tricarbonyl compounds, therefore their synthetic use exploits mainly their electrophilic properties. In addition, they can act as C-nucleophiles and participate in formal (4+2) cycloaddition reactions as ambiphilic reagents, as well as key intermediates in intramolecular cyclizations. The review analyzes the literature published in 2012–2019; the systematization is based on the structure of the formed heterocycle. The bibliography of the review includes 97 sources.