Construction of Axially Chiral Dialdehydes via Rhodium-Catalyzed Enantioselective C-H Amidation

Achieving axially chiral biaryl dialdehydes through asymmetric catalysis remains significantly challenging due to the lack of efficient strategies. In this report, we developed a rhodium-catalyzed enantioselective C-H amidation through chiral transient directing group strategy. With this new approach, a series of axially chiral amido dialdehydes were achieved in up to 86 % yields with 99.5 : 0.5 er. Furthermore, detailed mechanistic studies indicated that both the imine formation and C-H bond cleavage steps were reversible. More interestingly, the X-ray crystallographic analysis of Int-2 showed probable C-H/π interaction between biaryl group and chiral amine moiety. This process offered a convenient route to access axially chiral dialdehyde derivatives. More broadly, it demonstrated a new tool through transient and C-H/π synergistic interactions, which would stimulate further development of asymmetric catalytic system in enantioselective C-H functionalization.