solvent. In contrast, no incorporation of deuterium into the product was observed in the reduction of thiopivalophenone with BNAH or Me2PNPH under the same conditions. These results can be accounted for in terms of an electron transfer followed by a proton transfer from the model to substrate. This is the first and direct evidence for the ion radical-pair intermediacy for reductions by model compounds of
用
NAD(P)H、1-苄基-1,4-二氢烟酰胺 (BNAH) 或 N-(α-甲基苄基)-1-丙基-2,4-二甲基-1,4- 的模型化合物还原
噻吩二苯甲酮衍
生物二氢烟酰胺 (Me2
PNPH),在含有 O-
氘代醇的溶剂中得到在其次甲基位置部分
氘化的产物。
氘的含量取决于基材中取代基的特性和溶剂的极性。相比之下,在相同条件下用 BNAH 或 Me2
PNPH 还原
噻吩戊酮时未观察到
氘掺入产物中。这些结果可以根据电子转移和质子从模型转移到基板来解释。这是
NAD(P)H 模型化合物还原的离子自由基对中间体的第一个也是直接的证据。