Synthetic protocols, molecular polarity, and 13C NMR correlations for 1-aryl- and 1-diarylmethylidene-1H-cyclopropa[b]naphthalenes

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 σ_p⁺ constants for each atom within the cycloproparene moiety are provided for the 8–11 compounds that comprise each substitution pattern present in 5–10.