Synthesis, characterization, and reaction chemistry of tert-butyl hypofluorite
作者:Evan H. Appelman、David French、Eyal Mishani、Shlomo Rozen
DOI:10.1021/ja00057a022
日期:1993.2
tert-Butyl hypofluorite ((CH[sub 3])[sub 3]COF) can be synthesized by the low-temperature reaction of elemental fluorine with tert-butyl alcohol dissolved in propionitrile or acetonitrile. The isolated compound, which melts around -94[degrees]C and has an extrapolated boiling point of about +40[degrees]C, has been characterized by mass, NMR, and IR spectrometry. The [sup 19]F NMR shift of +67 ppm lies
叔丁基次氟酸盐 ((CH[sub 3])[sub 3]COF) 可以通过元素氟与溶解在丙腈或乙腈中的叔丁醇的低温反应合成。分离出的化合物熔点约为 -94°C,外推沸点约为 +40°C,已通过质谱、核磁共振和红外光谱进行表征。+67 ppm 的 [sup 19] F NMR 位移位于 HOF 和 CH[sub 3]OF 的相应位移之间,并且暗示着相当高的 OF 键能。虽然空间上拥挤,但次氟叔丁基与烯烃加成形成β-氟-叔丁氧基化合物。加成主要是反模式,区域选择性对应于迄今为止未知的叔丁氧基亲电试剂的作用。还形成了包含 F 和 CH[sub 2]CN 的加合物,后者衍生自乙腈溶剂。19 个参考文献,1 个标签。
tert-Butyl hypofluorite, t-BuOF, easily synthesized from t-BuOH and F-2, is a unique source of the novel electrophilic tert-butoxylium moiety t-BuO+. It was added to several benzylic double bonds to form vicinal fluoro-tert-butoxide derivatives. Not surprisingly, this bulky reagent is quite sensitive to steric hindrance. The process is electrophilic in nature, but since the reaction is relatively slow (20-60 min) formation of various radical species can take place, forming eventually several distinct byproducts. t-BuOF was also reacted with a number of enols, producing the corresponding alpha-tert-butoxy ketone derivatives in moderate to good yields. The best results were obtained with benzylic enol derivatives.