Preparation of Chiral Photosensitive Organocatalysts and Their Application for the Enantioselective Synthesis of 1,2-Diamines

Chiral phosphoric acid based organocatalysis and visible-light photocatalysis have both emerged as promising technologies for the sustainable production of fine chemicals. In this context, we have envisioned the design and the synthesis of a new class of chimeric catalytic entities that would feature both catalytic capabilities. Given their multitask nature, such catalysts would reveal 2 particularly attractive for the development of new catalytic transformations, tandem processes in particular. To this aim, several BINOL-based chiral phosphoric acids backbone presenting one or two visible-light sensitive thioxanthone moieties have been prepared and studied. The utility of these new photoactive chiral organocatalysts is then demonstrated in the enantioselective tandem three-component electrophilic amination of enecarbamates. Of note, the C1-symmetric organo/photo catalyst has given a better catalytic activity than those presenting a C2 symmetry.