Santiago Ana N, Toledo Carlos A, Rossi Roberto A
INFIQC, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Haya de la Torre esq. Medina Allende, 5000 Córdoba, Argentina.
J Org Chem. 2002 Apr 19;67(8):2494-500. doi: 10.1021/jo016151h.
The reactions of 1-bromo-, 1-iodo-, 2-bromo-, 1,3-dibromo-, and 1,4-dibromoadamantane with Me(3)Sn(-) ions were studied in liquid ammonia. The photostimulated reaction of 1-haloadamantane (1-XAd, X = Br, I) or 2-BrAd with Me(3)Sn(-) ions gave in a few minutes excellent yields of the substitution products. The 1,3-dibromo- and 1,4-dibromoadamantane with Me(3)Sn(-) ions also reacted very fast under irradiation to give the disubstitution product in good yields. In competition experiments, 1-ClAd is 5.3 times more reactive than 5-chloro-2-adamantanone (9) toward Me(3)Sn(-) ions in liquid ammonia. When the nucleophile is the Ph(2)P(-) ion, 1-ClAd reacts 2.4 times faster than 9. This is the first time that no redox catalysis was observed when the bridgehead compound bears a carbonyl group as a pi acceptor. On the other hand, the nucleophile Me(3)Sn(-) ion was ca. >1000 times more reactive than Ph(3)Sn(-) ions toward 1-adamantyl radicals, in contrast to the behavior of aryl radicals, where both nucleophiles have the same reactivity.
在液氨中研究了1-溴代金刚烷、1-碘代金刚烷、2-溴代金刚烷、1,3-二溴代金刚烷和1,4-二溴代金刚烷与Me(3)Sn(-)离子的反应。1-卤代金刚烷（1-XAd，X = Br，I）或2-BrAd与Me(3)Sn(-)离子的光刺激反应在几分钟内就得到了高产率的取代产物。1,3-二溴代金刚烷和1,4-二溴代金刚烷与Me(3)Sn(-)离子在光照下也反应很快，以良好的产率得到二取代产物。在竞争实验中，在液氨中，1-ClAd与Me(3)Sn(-)离子反应的活性比5-氯-2-金刚烷酮（9）高5.3倍。当亲核试剂为Ph(2)P(-)离子时，1-ClAd的反应速度比9快2.4倍。当桥头化合物带有羰基作为π受体时，首次观察到没有氧化还原催化作用。另一方面，亲核试剂Me(3)Sn(-)离子对1-金刚烷基自由基的反应活性比Ph(3)Sn(-)离子高约1000倍，这与芳基自由基的行为相反，在芳基自由基反应中，两种亲核试剂具有相同的反应活性。
