SmI2(H2O)n arising from the addition of large amounts of H2O (500 equiv) are much less reactive toward reduction of aromatic hydrocarbons than complexes of SmI2(H2O)n prepared using 50 equiv of H2O. We also report that SmI2(H2O)n cleanly mediates Birch reductions of substrates bearing at least two aromatic rings in excellent yields, at room temperature, under very mild reaction conditions, and with selectivity
mar(II)
碘化物-
水络合物非常适合介导具有挑战性的电子转移反应,但尚未确定这些强力还原剂的有效氧化还原电位。本文中,我们报告了SmI 2(H 2 O)n与一系列不饱和烃和卤代烷的反应性的检查结果,还原电位相对于SCE为-1.6至-3.4V。我们发现,SmI 2(H 2 O)n与还原电位比-SCE更正的负电位大于-2.21 V的底物发生反应,而SCE比SmI 2(H 2 O)n的热力学氧化还原电位高得多。通过电
化学方法测定(相对于SCE最高-1.3 V)。有效氧化还原电位的测定表明,
水与SmI 2的配位将使Sm(II)的有效还原能力提高0.4 V以上。我们证明了SmI 2(H 2 O)n的络合物是由于大量添加而产生的的H 2 O(500当量)与使用50当量的H 2 O制备的SmI 2(H 2 O)n的配合物相比,对
芳烃的还原反应要小得多。我们还报告了SmI 2(H 2 O)n 在室温下,