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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Restricted rotation in 9-phenyl-anthracenes: a prediction fulfilled
Kirill Nikitin1, Helge Müller-Bunz, Yannick Ortin
1School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland. kirill.nikitin@ucd.ie
Abstract:
The calculated phenyl rotation barrier in 9-phenylanthracene has been reported as ~21 kcal mol(-1), but experimental verification of this barrier is limited by its intrinsic symmetry. V-T NMR indicated the barrier to interconversion of the syn (C(2v)) and anti (C(2h)) rotamers of 9,10-bis(3-fluorophenyl)anthracene to be ~21 kcal mol(-1). Likewise, the V-T NMR spectra of 9-(1-naphthyl)-10-phenylanthracene reveal that the rotational barrier of the unsubstituted phenyl ring is at least 21 kcal mol(-1).
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