The kinetic behavior of the Lewis base-catalyzed sulfenocyclization of polyenes in hexafluoroisopropyl alcohol (HFIP) was explored. The rate of reaction is not dependent on the electronic properties of the terminal nucleophile, suggesting that this capture step is not rate limiting. Additionally, fractional orders were observed for two of the reaction components. This intriguing profile appears unique to the polyene sulfenocyclization reaction and is not merely due to solvent effects.
Keywords: Lewis base catalysis; cyclization; hexafluoroisopropyl alcohol; kinetics; polyenes; sulfenocyclization.