Synthesis of Benzofurans <i>via</i> Tandem Rhodium‐Catalyzed C(<i>sp</i>³)H Insertion and Copper‐Catalyzed Dehydrogenation

Abstract

Abstract A sequentially catalyzed cascade approach for the synthesis of benzofuran derivatives (up to 88% yield) from 1‐sulfonyl‐1,2,3‐triazoles has been developed. The cascade reaction involves sequential rhodium‐catalyzed C( sp 3 )H insertion and copper‐catalyzed aerobic oxidation. The method was made more convenient towards the synthesis of benzofurans starting from terminal alkynes via a one‐pot sequential copper‐catalyzed alkyne‐azide cycloaddition (CuAAC)/CH insertion/dehydrogenation cascade reaction. Moreover, the utility of the cascade approach was demonstrated in the synthesis of the indole framework. magnified image