An Air-Stable Alkene-Derived Organic Radical Cation

Alkenes are known
to undergo oxidation to radical cations and dications.
The radical cations are often highly reactive and not stable under
air. Herein, we report the synthesis, isolation, characterization,
and molecular structure of an alkene-derived radical cation A, which is stable in air both in the solid state and in solution.
The access to this compound was facilitated from E-diamino tri-substituted alkene B as a synthon for the
synthesis of A through one-electron oxidation. The E-diamino tri-substituted alkene B was synthesized
by the two-electron reduction of N,N′-1,2-propylene-bridged bis-2-phenyl-pyrrolinium cation C. Under two-electron oxidation, alkene B transforms
back to cation C involving a double carbocation rearrangement.