Preparation of -1,2,3,3,3-pentafluoropropene, -1,2,3,3,3-pentafluoropropene and -1-iodopentafluoropropene

Synthesis and Spectroscopic Characterization of Potassium Polyfluoroalken-1-yltrifluoroborates

“…(1), cis-, trans-Cl (2), cis-C 2 F 5 (3), cis-C 6 F 13 (4), trans-C 4 F 9 (5), trans-C 4 H 9 (6), trans-C 6 H 5 (7). The position of substituent R is related to the BF 3 group.…”

“…trans-RCF=CFLi R = C 4 H 9 , C 6 H 5 However, this pathway is not available for the stereoselective preparation of trans-C n F 2n+1 CF=CFH because perfluoroalkylllithium reagents have too low nucleophilicity and insufficient thermal stability. The required trans-1 H-perfluoro-1-hexene was obtained by Burton's method [6] via the stereospecific nucleophilic phosphodefluoridation of the easily available perfluoro-1-hexene.…”

“…With R = CF 3 or C 2 F 5 , they can be obtained by the isomerisation of trans-CF 3 CF=CFH or CF 2 =CFCF 2 CF 2 H with SbF 5 [6,7]. This procedure can not be applied to hydroperfluoroalkenes with longer chains because they give a mixture of internal isomers in addition to the desired products [8].…”

“…After addition of water (2 ml) the volatile products were distilled from the stirred solution at 120 to 130°C (bath) during 3 h. The distillate was washed with water, dried with MgSO 4 and P 4 O 10 and re-distilled to yield 16.7 g (60%) of trans-1 H-perfluoro-1-hexene, b. p. 55±58°C. C6 HF 11 (282,06): calculated C 25.55, H 0.36, F 74.09; found C 26.0, H 0.42, F 73.8%.…”

“…mª (cm ±1 ): 1363 m, 1332 m, 1264 s, 1240 vs, 1210 vs, 1137 vs, 1081 w, 1063 m, 1045 m, 1010 vs, 981 s, 878 m, 863 s, 770 m, 752 s, 734 vs, 702 w, 656 w, 624 m, 598 s, 569 w, 534 m, 472 m, 409 w.Potassium trans-1,2-difluorohexen-1-yltrifluoroborate(6). A solution of trans-1,2-difluoro-1-hexene (10.0 g, 83 mmol) in THF (100 ml) was cooled to ±60°C and 2.5 M BuLi in hexane (33 ml, 83 mmol) was added drop by drop within 20 min.…”