Related Experiment Video
Updated: Aug 21, 2026

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Synthetic protocols, molecular polarity, and 13C NMR correlations for 1-aryl- and
1School of Chemical & Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand. brian.halton@vuw.ac.nz
Abstract:
The Peterson olefination for alkylidenecycloproparene synthesis from a 1,1-disilylcycloproparene has been refined into five distinct protocols that have provided 43 new aryl- (5 and 6) and diaryl- (7 and 8), and aryl(phenyl)- (9 and 10) methylidene derivatives. The permanent dipole moments of these and other previously reported compounds have been measured and the direction of the dipole, to or from the cycloproparenyl moiety, established for each compound. The 13C NMR spectra are fully assigned and linear correlations of carbon chemical shift with the Hammett sigmap+ constants for each atom within the cycloproparene moiety are provided for the 8-11 compounds that comprise each substitution pattern present in 5-10.
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
Aromatic Hydrocarbon Anions: Structural Overview
Due to the absence of continuous overlap of p...
Frost Circles for Different Conjugated Systems
¹H NMR: Long-Range Coupling
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
NMR Spectroscopy of Aromatic Compounds

