<i>Ortho</i> ‐Alkynyl Quinone Methides as Privileged Intermediates in Synthesis of Polycyclic Frameworks: A Short Review

Ortho-alkynyl quinone methides (o-AQMs) are valuable building blocks in organic synthesis, featuring a unique hybrid structure that combines an alkyne with an ortho-quinone methide (o-QM) unit. This architecture results in a synergistic interplay of reactivities: the alkyne moiety participates in addition and cyclization reactions, while the o-QM unit is prone to nucleophilic addition and redox transformations. Such dual functionality renders o-AQMs highly versatile as reactive intermediates for constructing polycyclic frameworks, especially oxygen-containing heterocycles like furans and pyrans. This review summarizes the physicochemical properties, synthetic methods, and applications of o-AQMs as privileged intermediates. It provides a comprehensive overview of the current state and emerging trends in utilizing o-AQMs for heterocycle synthesis, highlighting their growing potential to advance synthetic chemistry.