Annulation of o‑Quinodimethanes through N‑Heterocyclic Carbene Catalysis for the Synthesis of 1‑Isochromanones

The activation of 2-(bromomethyl)­benz­alde­hydes using N-heterocyclic carbenes represents a novel approach to the generation of o-quinodimethane (o-QDM) intermediates. Coupling with ketones such as phenylglyoxylates, isatins, or trifluoromethyl ketones via [4 + 2] annulation gives access to functionalized 1-isochromanones.