Thermal and BF3?Et2O-catalyzed cleavage of 1-hydrohexafluoroisobutenyloxytrimethylsilane. Perfluoromethacrolein, its isomers, dimers, and homopolymers
作者:A. Yu. Volkonskii、E. M. Kagramanova、E. I. Mysov、N. E. Mysova
DOI:10.1007/s11172-005-0019-8
日期:2004.8
During vacuum pyrolysis in a quartz or steel tube, 1-hydrohexafluoroisobutenyloxytrimethylsilane (1) eliminates fluorotrimethylsilane to give perfluoromethacrolein, which was detected by NMR. Similar pyrolysis of silane 1 over KF results in E- and Z-β-hydrotetrafluoromethacryloyl fluorides. At 20 °C, perfluoromethacrolein undergoes homopolymerisation and/or cyclodimerization to yield 4,4-difluoro-2-pentafluoroisopropenyl-5-trifluoromethyl-4H-1,3-dioxin, which rearranges into E-7,7,7-trifluoro-2,6-bis(trifluoromethyl)-4-oxahepta-2,5-dienoyl fluoride under the action of BF3⋅Et2O. The same fluoride is also formed, together with fluorotrimethylsilane, directly from silane 1 under the action of BF3⋅Et2O.
在石英或钢管的真空热解过程中,1-氟代六氟异丁烯氧基三甲基硅烷(1)通过消除氟三甲基硅烷生成全氟甲克戎醛,该化合物已通过核磁共振(NMR)检测到。对硅烷1在KF作用下的类似热解反应生成E-和Z-β-氟代四氟甲克醛。 在20°C时,全氟甲克戎醛发生均聚合和/或环二聚反应,生成4,4-二氟-2-五氟异丙烯基-5-三氟甲基-4H-1,3-二氧烷,该化合物在BF3⋅Et2O的作用下重排形成E-7,7,7-三氟-2,6-双(三氟甲基)-4-氧七烯-2,5-二酰氟。相同的氟化物也可以在BF3⋅Et2O的作用下,直接从硅烷1生成,并与氟三甲基硅烷一起生成。