Synthesis of Cyclopropenes and Fluorinated Cyclopropanes via Michael Initiated Ring Closure of Alkyl Triflones.

A facile synthesis of cyclopropenes and fluorinated cyclopropanes from readily available alkyl triflones was developed. The reaction, regardless of electronic effect, gave products in good to excellent yields and moderate diastereoselectivity. The mechanism may involve tandem Michael addition of triflones/intramolecular nucleophilic cyclization (elimination of -SO 2 CF 3 )/elimination of fluoride.