Synthetic Pathways to 1, 2-Dicarbonyl Compounds: Progress, Challenges, and Opportunities.

1,2-Dicarbonyl compounds or α-dicarbonyls are important synthetic intermediates widely used in organic synthesis, medicinal chemistry, and materials science due to their unique reactivity and versatility. In recent years, significant progress has been made in developing efficient methods for synthesizing them from diverse substrates, including heterocycles, alkenes, alkynes, ketones, and aromatic systems. This review provides an overview of recent advances reported between 2014 and 2026, covering transition-metal-catalyzed, metal-free, photocatalytic, electrochemical, and catalyst-free strategies. Emphasis is placed on reaction mechanisms, substrate scope, functional-group tolerance, and sustainability. The limitations associated with substrate compatibility, cost-effectiveness, and sustainability are also critically discussed. Finally, emerging directions, such as green oxidants, heterogeneous catalysis, photocatalysis, and electrochemical methods, are highlighted as promising avenues for future development. This review aims to provide a comprehensive resource to guide the design of efficient and sustainable strategies for synthesizing 1,2-dicarbonyl compounds.