BITHIENOLs: Promising C2-Symmetric Biheteroaromatic Diols for Organic Transformation

2,2′,5,5′-Tetraphenyl-3,3′-bithiophene-4,4′-diol, the first member of a new class of chiral C2-symmetric atropisomeric diols based on a biheteroaromatic scaffold, has been synthesized. Dynamic enantioselective HPLC experiments revealed a racemization barrier of 22.9 kcal/mol at 25 °C, which is high enough to permit the chromatographic collection of both enantiomers on a semi-preparative scale, but at the borders of application as a promoter in asymmetric catalysis