Pyrrolo[2,1-a]isoquinolines as multitasking organophotocatalysts in chemical synthesis

We demonstrate the design and synthesis of pyrrolo[2,1-a] isoquinolines (PIqs) bearing electron-withdrawing groups, which are excited under irradiation with visible light to display wider redox windows and higher triplet-state energies. The photophysical and electrochemical characters of PIqs can be tailored by modification of the electron-withdrawing groups and their positions, enabling redox-neutral (hetero)biaryl cross-coupling between aryl halides and (hetero)arenes, nickel-catalyzed amination and oxygenation of aryl halides, and decarboxylative cross-coupling between alpha-amino acids and aryl halides, as well as a set of molecular transformations driven by triplet-triplet sensitization under irradiation with visible light.