Reduction of gem-halofluorocyclopropanes with tributyltin hydride

Free-Radical Rearrangements

“…The tin hydride-cyclopropyl halide reaction has been employed most commonly (708)(709)(710)(711)(712)(713)(714)(715)(716)(717), but other methods of generating and trapping cyclopropyl radicals have also been used (394-394c f [718][719][720][721][722][723][724][725][726][727][728]. The re sults with tin hydrides have varied through the entire spectrum of pos sibilities, from complete inversion (708) through partial inversion (709,710), complete configurational equilibration (711,712), and partial reten tion (713)(714)(715)(716), all the way to complete retention (710,714,716,717). A similar spectrum of results has been obtained in other systems (394-394b, 718-728).…”

Nature's hydrides: rapid reduction of halocarbons by folate model compounds

“…The high reactivity and selectivity observed suggests that 1H may become a new substitute for the tin hydrides 18 and hydrosilanes 19 previously used for selective debrominations.…”

Memory of chirality in reactions involving monoradicals

“…Cyclopropyl radicals represent the earliest class of cycloalkyl radicals showing MoC effects and this topic has been reviewed by Walborsky [22]. They were first examined by Ando et al in 1970 who showed that the dehalogenation of 1-halo-1-fluorocyclopropane was occurring with retention of configuration and that the level of retention of configuration was influenced by the source of hydrogen atom [23]. For instance, Bu 3 SnH afforded the fluorocyclopropane with full retention of configuration at 130-140 C. By using a slower hydrogen donor such as tributylsilane, partial epimerization of the intermediate radical could be detected.…”