Ring Opening of Vinylcyclopropane Radical Cations via Stereoselective Sigmatropic Shifts

Radical cations of disubstituted cyclopropanes: stereoelectronic effects on hyperfine coupling

“…Non‐symmetrically disubstituted cyclopropane radical cations containing a vinyl group have been probed by experiment and calculation . For bicyclic derivatives, in which the functionalities are locked in either the syn or the anti configuration, electron transfer‐induced CIDNP effects suggest a range of structure types with subtle differences.…”

Oxidation of Aryl- and Diarylcyclopropanes in a Pentasil Zeolite: Ring Opening with Deprotonation or Net Hydrogen Migration

“…This reaction typically results in ring-opened products bearing either an alkoxy group (e.g., 6, R ϭ CH 3 ) or an alkoxy and a pcyanophenyl group (e.g., 7); these products are formed by the well-established nucleophilic capture of the corresponding radical cation by the alcohol with ring-opening. [8,9,22,23] In the reaction of trans-1, no isomerization products were observed; apparently nucleophilic capture is faster than isomerization.…”

“…[8] [9] Thus, sabinene radical cation (S •ϩ ) undergoes a In this paper, we report results pertinent to the structure and reactivity of cis-and trans-1,2-diphenylcyclopropane, cis-, trans-1. CIDNP studies have shown that cis-and trans-1…”

Triphenylpyrylium Tetrafluoroborate-Sensitized Photochemistry of the Terpenes Sabinene, α-Phellandrene, and α- and γ-Terpinene

“…Among unimolecular reactions, geometric isomerizations [16,17] and several molecular rearrangements, [18][19][20] including sigmatropic shifts, [21,22] have been studied.…”

“…[33] The reaction of terpene radical cations in the absence of nucleophiles has been studied to a lesser extent. [22] The radical cations of α-and β-pinene were deprotonated by the sensitizer radical anion (tetrachlorosemiquinone); β-pinene was converted into αpinene, whereas α-pinene was dehydrogenated with formation of verbenene. [22] The radical cations of α-and β-pinene were deprotonated by the sensitizer radical anion (tetrachlorosemiquinone); β-pinene was converted into αpinene, whereas α-pinene was dehydrogenated with formation of verbenene.…”