Enantioselective Nazarov Cyclizations Catalyzed by an Axial Chiral C6 F5 -Substituted Boron Lewis Acid.

A chiral variant of B(C6 F5 )3 with a 3,3'-disubstituted binaphthyl backbone is shown to catalyze Nazarov cyclizations with high levels of enantio- and diastereocontrol. The parent B(C6 F5 )3 also promotes these ring closures efficiently. This electrocyclization is another example of the still small family of C-C bond formations mediated by B(C6 F5 )3 as the catalyst.