Yang Zhen-Yu
DuPont Central Research and Development, Experimental Station, Wilmington, Delaware 19880-0328, USA.
J Org Chem. 2003 May 30;68(11):4410-6. doi: 10.1021/jo030014y.
Various highly fluorinated cyclopropanes 1 were prepared by reaction of the appropriate fluorinated olefins with hexafluoropropylene oxide (HFPO) at 180 degrees C. The fluorinated nitrile 1e was converted to the triazine derivatives 2a and 2b by catalysis with Ag(2)O and NH(3)/(CF(3)CO)(2)O, respectively. The fluorinated cyclopropanes reacted with halogens at elevated temperatures to provide the first useful, general synthesis of 1,3-dihalopolyfluoropropanes. At 150-240 degrees C, hexafluorocyclopropane and halogens X(2) produce XCF(2)CF(2)CF(2)X (X = Cl, Br, I) in 50-80% isolated yields. Pentafluorocyclopropanes c-C(3)F(5)Y [Y = Cl, OCF(3), OC(3)F(7) and OCF(2)CF(CF(3))OCF(2)CF(2)Z; Z = SO(2)F, CN, CO(2)Me] react regiospecifically at 150 degrees C to give XCF(2)CF(2)CFXY, c-C(3)F(5)Br reacts regioselectively with Br(2) to give a 16.7:1 mixture of BrCF(2)CF(2)CFBr(2):BrCF(2)CFBrCF(2)Br, whereas c-C(3)F(5)H reacts unselectively with I(2) to produce a statistical 2:1 mixture of ICF(2)CF(2)CFHI:ICF(2)CFHCF(2)I. Tri- and di(pentafluorocyclopropyl) derivatives 2 also undergo ring-opening reaction with halogens to give 16 and 17. Upon treatment of tetrafluorocyclopropanes 1j, 1k, and 1l with Br(2) or I(2), ring opening occurred exclusively at substituted carbons to give XCF(2)CF(2)CXY(2). Thermolysis of the ring-opened product ICF(2)CF(2)CFIOR(F) at 240 degrees C gave R(F)I and ICF(2)CF(2)COF in high yields.
通过在180℃下使适当的氟化烯烃与六氟环氧丙烷（HFPO）反应制备了各种高度氟化的环丙烷1。氟化腈1e分别通过用Ag₂O和NH₃/(CF₃CO)₂O催化转化为三嗪衍生物2a和2b。氟化环丙烷在高温下与卤素反应，首次实现了1,3 - 二卤多氟丙烷的有用且通用的合成。在150 - 240℃下，六氟环丙烷与卤素X₂生成XCF₂CF₂CF₂X（X = Cl、Br、I），分离产率为50 - 80%。五氟环丙烷c - C₃F₅Y [Y = Cl、OCF₃、OC₃F₇和OCF₂CF(CF₃)OCF₂CF₂Z；Z = SO₂F、CN、CO₂Me]在150℃下发生区域选择性反应生成XCF₂CF₂CFXY，c - C₃F₅Br与Br₂发生区域选择性反应生成BrCF₂CF₂CFBr₂:BrCF₂CFBrCF₂Br的16.7:1混合物，而c - C₃F₅H与I₂反应无选择性，生成ICF₂CF₂CFHI:ICF₂CFHCF₂I的统计2:1混合物。三（五氟环丙基）和二（五氟环丙基）衍生物2也与卤素发生开环反应生成16和17。用Br₂或I₂处理四氟环丙烷1j、1k和1l时，开环仅发生在取代碳上生成XCF₂CF₂CXY₂。开环产物ICF₂CF₂CFIOR(F)在240℃下热解高产率地生成R(F)I和ICF₂CF₂COF。
