Abstract
The synthesis of four original telomers containing 3,3,3-trifluoropropene RF(C3H3F3)nI [ with n=1 and 2 and RF =C6F13 or (CF3)2CF] and their allyl derivatives CH2=CH-CH2 – (C3H3F3)n-RF are presented. The allylic-containing fluorotelomers were prepared from a three-step reaction. The first step concerned the thermal and peroxide telomerization of 3,3,3-trifluoropropene ( TFP) with perfluoropropyl 2-iodide or tridecafluoro hexyl iodide leading to monoadduct and diadduct with a ratio depending on the R0=[RFI]0/[TFP]0 and the reaction temperature. The amount of monoadduct increases up to 70-75% vs dimmer (30-25%) at temperatures up to 180 °C (thermal) and 150°C (DTBP) and R0 up to 1.5. Then the telomers reacted onto allyl acetate yielding RF(C3H3F3)nCH2CH(I)CH2OCOCH3 (n=1,2) in 75-80% yields. The third phase consisted in a deiodoacetalization of these iodoacetates into CH2=CH-CH2(C3H3F3)nRF by means of activated zinc dust and CH3OH in 80-85% yield. All the intermediate compounds were characterized by NMR spectroscopy.