Remote Steric Effect Propagation through Naphthalene Hydrogens and/or Molecular Skeleton: Structural Determination of Brominated Product of Dinaphtho[2,1‐b:1′,2′‐d]furan

Abstract

We performed a bromination reaction of dinaphtho[2,1‐b:1′,2′‐d]furan (DNF). Although similar reactions have been reported, the regioselectivity of this reaction has not been clarified. Single‐crystal diffraction study confirmed that two bromine atoms were introduced on 5‐ and 9‐positions of DNF. Detailed studies revealed that the steric effect of the bulky bromine atoms propagated through the peripheral hydrogens and/or the skeleton of DNF to result in the large helicity. This structural characteristic became apparent from the shift of the signals of Fjord hydrogens in the 1H NMR spectra. Theoretical studies also supported our proposed remote steric effect.