analogous tetrachloro ansa compound exo-FcCH(2)P(S)(CH(2)O)(2)[P(Cl)N](2)(Cl(2)PN) (5), however, did not transform to the chlorinated spiro compound (6) in the presence of these bases. With excess of CsF, P-Cl bonds of 5 were found to undergo fluorination leading to the formation of 2, which transformed to spirocyclic compound 3. Time dependent (31)P NMR spectroscopy was used to monitor this transformation
氟化ansa取代的环
磷腈内-FcCH(2)P(S)(CH(2)O)(2)[P(F)N](2)(F(2)
PN)[Fc =
二茂铁基](1)和exo-FcCH(2)P(S)(CH(2)O)(2)[P(F)N](2)(F(2)
PN)(2)容易转化为
螺环化合物[FcCH(2 )P(S)(CH(2)O)(2)
PN](F(2)
PN)(2)(3)不仅在存在CsF的情况下,而且还与非
氟化碱(例如Cs(2))一起存在CO(3),K(2)CO(3),KOBu(t),Et(3)N,
DABCO,
DBN和
DBU。但是,类似的四
氯ansa化合物exo-FcCH(2)P(S)(CH(2)O)(2)[P(Cl)N](2)(Cl(2)
PN)(5)没有在这些碱的存在下转化为
氯化螺化合物(6)。在过量的CsF下,发现5的P-Cl键发生
氟化导致形成2,其转化为
螺环化合物3。使用时间依赖性(31)P NMR光谱法监测该转化。