Dual Functionality of 2,2'-Bibenzothiazole in Organic Photocatalysis.

The advancement of metallaphotoredox catalysis in organic synthesis largely relies on the development of competent photosensitizers and additional organic ligands stabilizing metal cocatalysts. To simplify the complex and costly metallaphotoredox systems, we hereby introduce 2,2'-bibenzothiazole (dBZ), an organic chromophore exhibiting unprecedented dual functionality in organic photocatalysis. A series of photophysical, electrochemical, and photocatalytic studies demonstrated the competence of dBZ in driving various organic transformations as a sole photocatalyst. More importantly, when coupled with nickel acetate, dBZ was able to perform many challenging C-C and C-N coupling reactions in the absence of additional organic ligands, marking a departure from conventional metallaphotoredox strategies and highlighting its unique role in streamlining photocatalytic protocols. In short, the dual functionality of dBZ not only simplifies the photocatalytic system but also reduces the overall cost, representing an innovative direction in organic photocatalysis.