Nickel-Catalyzed Sonogashira C(sp)–C(sp2) Coupling through Visible-Light Sensitization

• DOI: 10.1021/acs.joc.0c01177
• Publication Date: 2020-06-12T07:49:50Z
• Authors: Da-Liang Zhu; Ruijie Xu; Qi Wu; Hai-Yan Li; Jian-Ping Lang; Hong-Xi Li
• Keywords: Sonogashira coupling; Acetylide; Alkyne; Aryl halide; Reductive elimination; Transmetalation

An efficient method for visible-light-initiated, nickel-catalyzed Sonogashira C(sp)–C(sp2) coupling has been developed via an energy-transfer mode. Thioxanthen-9-one as a photosensitizer could significantly accelerate the arylation of alkynes with wide range (hetero)aryl halides in high yields. The cross-coupling reaction undergoes stepwise oxidative addition arylhalide to nickel(0), transmetalation resulting aryl–Ni(II) halide species Zn(II) acetylide into species, energy transfer from excited state thioxanthen-9-one acetylide, and reductive elimination aryl alkyne.