Krow Grant R, Gandla Deepa, Guo Weiwei, Centafont Ryan A, Lin Guoliang, Debrosse Charles, Sonnet Philip E, Ross Charles W, Ramjit Harri G, Cannon Kevin C
Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA.
J Org Chem. 2008 Mar 21;73(6):2122-9. doi: 10.1021/jo702155v. Epub 2008 Feb 22.
The ability of Selectfluor to act as a nucleofuge for hydrolysis of beta-anti-halides was investigated with N-alkoxycarbonyl derivatives of 6-anti-Y-7-anti-X-2-azabicyclo[2.2.1]heptanes and 4-anti-Y-8-anti-X-6-azabicyclo[3.2.1]octanes. The azabicycles contained X = I or Br groups in the methano bridge and Y = F, Br, Cl, or OH substituents in the larger bridge. The relative reactivities of the halides were a function of the azabicycle, the halide, and its bridge and the addition of Selectfluor or HgF(2) as a nucleofuge. All halide displacements occurred with retention of stereochemistry. Selectfluor with sodium bromide or sodium chloride, but not sodium iodide, competitively oxidized some haloalcohols to haloketones. A significant 15.6 Hz F...HO NMR coupling was observed with 4-anti-fluoro-8-anti-hydroxy-6-azabicyclo[3.2.1]octane.
利用6-反式-Y-7-反式-X-2-氮杂双环[2.2.1]庚烷和4-反式-Y-8-反式-X-6-氮杂双环[3.2.1]辛烷的N-烷氧羰基衍生物，研究了Selectfluor作为β-反式卤化物水解的离去基团的能力。氮杂双环在亚甲基桥中含有X = I或Br基团，在较大的桥中含有Y = F、Br、Cl或OH取代基。卤化物的相对反应活性是氮杂双环、卤化物及其桥以及添加Selectfluor或HgF₂作为离去基团的函数。所有卤化物取代反应均发生构型保持。Selectfluor与溴化钠或氯化钠（而非碘化钠）能将一些卤代醇竞争性地氧化为卤代酮。在4-反式氟-8-反式羟基-6-氮杂双环[3.2.1]辛烷中观察到显著的15.6 Hz F…HO NMR偶合。
