A chiral copper catalyst selects enantiofaces by assembled attractive interactions.

The silver‐catalyzed asymmetric aldol reaction of isocyanoacetic acid derivatives with aldehydes has been developed by employing a chiral prolinol‐phosphine as a hydrogen‐bond‐donating P,N,O ligand. DFT calculations indicated that the reaction proceeds in a stepwise manner, involving C−C bond forming carbonyl addition and subsequent enantioselectivity‐determining oxazoline ring formation. An O−H⋅⋅⋅O/sp3‐C−H⋅⋅⋅O two‐point hydrogen bond donated by the prolinol moiety of the ligand activates the aldehyde in the C−C bond formation step and facilitates the subsequent cyclization under stereocontrol by the catalyst. The calculations further suggest that additional nonclassical C−H⋅⋅⋅O hydrogen bonds as well as London dispersion interactions may also participate synergistically in the stereocontrol.