Benzeneseleninic Acids (BSA) and Photocatalysis: An Alternative Duo for the Synthesis of 3‐Selanylindoles

Abstract A novel eco‐friendly methodology for the synthesis of 3‐selanylindoles has been established, circumventing the requirement for transition metal catalysis, strong oxidants and elevated reaction temperatures. In the present protocol a photocatalytic strategy was elegantly developed for the use of benzeneseleninic acid (BSA) derivatives as a selenium‐source reagent, reacting with indole derivatives, to access 3‐selanylindoles in moderate to good yields. A total of fourteen derivatives were selectively prepared, which among three are unprecedented. In addition to the synthetic advantages, this study gives significant insights into the use of BSA derivatives as reagent to construct Se(II)‐decorated products.