Base‐mediated Benzannulation Reactions for the Synthesis of Densely Functionalized Aryl α‐Keto Esters

Abstract A novel and straightforward strategy for the construction of versatile densely functionalized aryl α‐keto esters is disclosed through a one‐pot and efficient [4+2] benzannulation reaction of α‐cyano‐β‐methylenones and ynediones, which could be synthesized easily from the corresponding starting materials. This protocol features high yield, mild metal‐free reaction condition, high atom economy, high functional‐group tolerance, easy handing and gram‐scale synthesis.