Convergent Strategy for the Synthesis of Oxa-, Thia-, and Selena[5]helicenes By Acetylene-Activated SNAr Reactions

A tandem acetylene-activated SNAr-anionic cyclization strategy is presented for the synthesis of chalcogen-containing hetero[5]helicenes. Oxa-, thia-, and selena[5]helicenes are accessed from commo...