Divergent Approach to Highly Substituted Arenes via [3 + 3] Annulation of Vinyl Sulfoxonium Ylides with Ynones.

Herein, we report the divergent benzannulation for highly substituted arenes using vinyl sulfoxonium ylides and ynones. The addition of ynone at the γ-position of vinyl sulfoxonium ylides leads to dienyl sulfoxonium ylide that can undergo selective annulation under different conditions to give m -terphenyls and parabens. Moreover, control experiments and quantum chemical calculations reveal two distinct reaction mechanisms for both annulations.