Synthesis of a stable indium complex derived from γ-silyl-α,α-difluorobromopropyne: evaluation of experimental parameters

Fluoroallenes are potentially useful cyclization precursors because of the synergistic combination of fluorine’s unique stereolectronic features and the rich chemistry of allenes. We have optimized the experimental conditions needed for the formation of a difluoropropargylindium complex 2. Sonication, lower reaction temperatures (5 °C), and dilute concentration of the starting material (0.15 M) are required to maximize production of this complex. Although the structure of this complex remains unknown, we have found that the nature of the alkyl substituents on the silyl group does not influence the formation of 2 but it does affects the allenyl 5 to propargyl 4 ratio.