Synthesis of both enantiomers is a very important task not only in organic chemistry but also in medicinal and bioorganic chemistry.1 In chemical transformations, syntheses of both enantiomers are generally carried out using both enantiomers of chiral sources. While there are many chiral sources in nature, it is sometimes difficult to obtain both enantiomers, for instance, those of amino acids, monosaccharides, alkaloids, etc. When such chiral sources are employed in asymmetric syntheses, preparation of both enantiomers is difficult. On the other hand, from a mechanistic point of view, both enantiomers can be produced by controlling the enantiofaces of prochiral compounds. Therefore, it would be possible to control them by designing ligands that even have the same chirality.2,3 In this paper, we report an example of this; a switch of enantiofacial selectivities using similar types of ligands in chiral zirconiumcatalyzed aza Diels-Alder reactions. Recently, we reported the first enantioselective aza DielsAlder reactions of imino dienophiles using a chiral zirconium catalyst (1) prepared from Zr(O-t-Bu)4, (R)-6,6′-dibromo-1,1′binaphthol ((R)-Br-BINOL), and N-methylimidazole (NMI).4-6 According to these reactions, optically active piperidine derivatives having an S-configuration were prepared from achiral imines and 1-methoxy-3-trimethylsiloxy-1,3-butadiene (Danishefsky’s diene,7 2) in high enantioselectivities. In the course of our investigations to examine the catalystsubstrate interaction including the reaction course and to improve selectivities, it was indicated from both experiments and modeling studies that the substituents on the 3,3′positions of the BINOL ligand influenced the enantioselectivities strongly.8 We prepared 3,3′-substituted BINOL (3 and 4).9 In the presence of Zr(OBu)4 (20 mol %), (R)-6,6′-