Visible-Light-Mediated -Desulfonylation of -Heterocycles Using a Heteroleptic Copper(I) Complex as a Photocatalyst.

A photoredox protocol that uses a heteroleptic Cu (I) complex, [Cu(dq)(BINAP)]BF, has been developed for the photodeprotection of benzenesulfonyl-protected -heterocycles. A range of substrates was examined, including indazoles, indoles, pyrazoles, and benzimidazole, featuring both electron-rich and electron-deficient substituents, giving good yields of the -heterocycle products with broad functional group tolerance. This transformation was also found to be amenable to flow reaction conditions.