Radical additions to 1,2-dichlorodifluoroethene

Synthesis of fluorinated telomers

“…Radical addition of methanol onto chlorofluorinated alkenes is an appropriate and easy method to obtain halogenated alcohols. 23,24,[33][34][35][36][37]46 Recently, we have reported that the peroxidic addition of methanol onto chlorotrifluoroethylene (CTFE) 24 was regioselective since HOCH 2 CF 2 CFClH was the major product (95%). Optimal conditions were achieved when that reaction was initiated by 2,5-bis(tert-butylperoxy)-2,5dimethyl hexane (DHBP) at 407 K, and with a 40-fold excess of methanol over CTFE.…”

“…However, according to Modena et al 35 who reported the radical addition of THF and 2-propanol onto DCDFE, the DCDFE conversion rate increases with the initiator concentration. Hence, four telomerization reactions of DCDFE with methanol were carried out with different peroxide concentrations (Fig.…”

“…According to the literature, [33][34][35][36][37] the only method to produce HOCH 2 CFClCFClH concerns the radical addition of methanol onto DCDFE. Table 2 lists the different initiating systems (g-rays, UV irradiation or di-tert-butylperoxide) leading to the expected chlorofluoroalcohols in low yield (10-16%).…”

“…Finally, another, more exotic fluoroalkene, perfluoro-2-butene, was reacted with methanol under g-ray initiation, leading to the monoadduct mainly. 32 As a matter of fact, telomerization reactions of 1,2-difluoro-1,2-dichloroethylene (DCDFE) with methanol were carried out by several authors [33][34][35][36][37] in contrast to many other transfer agents: R X O-F (where R X represents a perhaloalkyl group containing 1 to 10 carbon atoms), 38 Cl 3 C-F, 39 CHCl 2 -F, 40 ClCH 2 -F, 40 several alcohols [such as HOCH 2 CH 2 -H, HOCH 2 CH 2 CH 2 -H, (CH 3 ) 2 C(OH)-H 33,35 and fluorinated ones 41 ], various ethers such as THF, dioxane and diethyl ether, 42 several acetates: CH 3 COOCH 2 -H, CH 3 COOCH(CH 3 )-H, CH 3 COOC(CH 3 ) 2 -H, 35 (RO) 2 P(O)-H (where R stands for CH 3 , C 2 H 5 or n-C 3 H 7 ). 43 In addition, a few telomerization reactions of 1,1-difluoro-2-chloroethylene (CDFE) have been carried out with various transfer agents: CCl 3 -F, 44 CF 3 -I 45 and CH 3 -CH 2 -OH.…”

“…43 In addition, a few telomerization reactions of 1,1-difluoro-2-chloroethylene (CDFE) have been carried out with various transfer agents: CCl 3 -F, 44 CF 3 -I 45 and CH 3 -CH 2 -OH. 46 In this way, the radical addition of methanol to 1,2-difluoro-1,2-dichloroethylene initiated by di-tert-butylperoxide, 35,37 g-rays 34 or UV radiation, 36 yielded mainly the monoadduct . However, no work has been reported on the radical telomerization of CDFE with methanol.…”