Synthesis of π-Extended Benzofulvenes: A Pd-Catalyzed Cascade Annulation Process Comprising C-C Bond Formation Followed by 1,6-Conjugate Addition.

A Pd-catalyzed cascade annulation process comprising C-C bond formation followed by 1,6-conjugate addition for π-extended benzofulvenes is reported. This process is compatible with a wide range of functionalities for both the p -quinone methides and internal alkynes, leading to diverse π-extended benzofulvenes. Additionally, this strategy is also applicable for aryne annulation with p -quinone methides.