Ar-BINMOLs with Axial and sp3 Central Chirality - Characterization, Chiroptical Properties, and Application in Asymmetric Catalysis

2'-Hydroxy-1,1'-binaphthalene-2-(arylmethanol) (Ar-BINMOLs), a family of new 1,1'-binaphthalene-2,2'-diol derivatives, prepared by a [1,2]-Wittig rearrangement, are introduced as new chiral molecules for the study of the modes of supramolecular aggregation on the basis of ESI-MS, NMR spectroscopy, differential scanning calorimetry (DSC), and Xray diffractometry. Characterization showed that Ar-BINMOLs exhibit different characteristics to BINOL and act as supramolecules due to hydrogen bonding and aromatic pi-pi/C-H center dot center dot center dot pi interactions. In particular, CD measurements of chiral and racemic Ar-BINMOL 2a in solution and the solid state show a strong Cotton effect, which revealed that amplification of chirality was observed because of the formation of a chiral supramolecular oligomer derived from the racemic monomer. To this end, the Ar-BINMOLs were used as supramolecular auxiliaries to mediate the Michael reaction of anthrone to (E)-beta-nitrostyrene and could give the Michael adduct with comparable enantioselectivities. In addition, the Ar-BINMOLs act as ligands to promote asymmetric 1,2-addition of diethylzinc to aldehydes, which resulted in excellent yields and enantioselectivities (up to >99.9% ee) in the reactions of diethylzinc with a broad range of aromatic aldehdyes.