Radical Addition of Diethyl Carbonate to Pentafluoropropen-2-yl Benzoate

Abstract

The reactivity in radical addition of diethyl carbonate to pentafluoropropen-2-yl benzoate [CF2=C(CF3)OCOC6H5] (BPFP) was investigated to afford the one-to-one addition product by the carbon-carbon bond formation in the presence of dibenzoyl peroxide at 80 °C. The reaction took place predominantly on the methylene group of diethyl carbonate. The mechanism of the hydrogen abstraction from diethyl carbonate followed by the addition to BPFP was proposed. This might be the first example that shows an addition of an organic compound bearing carbonyl group to a polyfluorinated vinyl compound. The method may be a facile way to prepare pentafluoroalkyl-substituted organic compounds by the formation of carbon-carbon bonds with the aid of fluorine atoms. The radical addition reaction of dipropyl carbonate, ethyl methyl carbonate, dibenzyl carbonate and ethylene carbonate to BPFP showed no peaks assignable to addition products by the analysis of reaction systems with GC-MS.

Stimulation on the addition reactivity of fluorinated vinyl monomers—Facile carbon–carbon bond formation by the aid of fluorine substituents

“…The results mentioned above indicate that the reaction takes place without the 1,7-radical shift mechanism, as shown in Scheme 2 [4], which is similar to that of the reaction of BPFP with THF. The mechanism of the hydrogen abstraction from diethyl…”

“…Mechanism of the reaction of BPFP and DEC [4]. carbonate followed by the addition to BPFP is proposed.…”

“…The additions of diethyl carbonate (DEC), dipropyl carbonate, ethyl methyl carbonate, dibenzyl carbonate and ethylene carbonate which possess two types of carbon-hydrogen bonds were examined [4]. The reaction of DEC with BPFP was carried out by reacting 107.8 mmol of DEC, 13.5 mmol of BPFP and 5.4 mmol of benzoyl peroxide (BPO) at 80 8C or of di-tert-butyl peroxide (DTBP) at 120 8C for 3 days.…”

“…The THF (2 mL) solution of polymer B (0.5 g), CH 3 CH 2 ONa (0.1 mmol in ethanol) and PBFA (0.2 mmol) was kept at room temperature for 1 day and reprecipitated by methanol to obtain polymer C. Numberaverage molecular weight and molecular weight distribution ðM w =M n Þ were: polymer A; 0.75 Â 10 4 …”