Triflimide activation of a chiral oxazaborolidine leads to a more general catalytic system for enantioselective Diels-Alder addition.

The strong acid triflimide ((CF3SO2)2NH) protonates chiral oxazaborolidines to form superactive, stable, chiral Lewis acids which are highly effective catalysts for a wide variety of enantioselective Diels-Alder reactions, documented herein by more than 20 examples.