Experimental and Mechanistic Exploration of Zn‐Catalyzed Sonogashira–type Cross‐Coupling Reactions

Abstract

AbstractOne of the most straightforward methods for the synthesis of disubstituted alkynes is the transition metal catalyzed Sonogashira‐type cross‐coupling reactions. Herein we report a detailed study of our recent research on the first Zn‐catalyzed protocol for C(sp2)–C(sp) cross‐coupling reaction of aryl iodides with terminal alkynes. A wide range of functional groups were tolerated in the reaction and both functionally and structurally diverse diaryl acetylenes were prepared efficiently using this protocol. The reaction mechanism for the Zn‐catalyzed Sonogashira‐type coupling reaction was investigated by means of density functional theory (DFT) methods on a model system. The calculations were performed using hybrid Becke Perdew Functional (BPV86) in conjugation with LANL‐2DZ basis set and found that the reaction pathway involves oxidative addition and reductive elimination mechanism.