The transfer hydrogenation (TH) of several aldimines has been studied using [RuCl(p‐cymene)(dmbpy)]BF₄, 1, (dmbpy=4,4′‐dimethyl‐2,2′‐bipyridine) as a precatalyst. Both neat water and a biphasic water/toluene mixture (w/t) have been successfully used as solvents. In the w/t medium the corresponding precursors, amine and aldehyde, were also used as substrates for a transfer hydrogenative reductive amination. Selective deuterium labeling of the resulting alkylated amines was the main goal of this work. On using D₂O the D‐content in the amine was negligible but a high level of D‐incorporation was achieved in D₂O/toluene. According to calculations, this is due to the effect of the relative rates of the hydride transfer and that of the RuH/D⁺ exchange. The incorporation of deuterium increases with time as a consequence of the reduction in the hydride transfer rate as the substrate concentration diminishes. The recyclability assays performed reflect the importance of pH in the selectivity of the TH towards the imine or the aldehyde resulting from imine hydrolysis.

中文翻译：

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双相介质减慢了转移加氢反应的速度，并允许在D2O中通过Ru-H / D +交换介导的亚胺中的胺进行选择性催化氘标记。

几个醛亚胺的转移氢化（TH）已使用将[RuCl（研究p -cymene）（dmbpy）] BF ₄，1，（dmbpy = 4,4'-二甲基-2,2'-联吡啶）作为前段催化剂。纯水和水/甲苯两相混合物（重量/吨）均已成功用作溶剂。在w / t介质中，相应的前体胺和醛也用作转移氢化还原胺化的底物。所得烷基化胺的选择性氘标记是这项工作的主要目标。使用D ₂ O时，胺中的D含量可以忽略不计，但D ₂中的D掺入量很高O /甲苯。根据计算，这是由于氢化物转移的相对速率和RuH / D ⁺交换的相对速率的影响。随着底物浓度降低，氢化物转移速率降低，氘的掺入量随时间增加。进行的可回收性分析反映了pH在TH对亚胺或亚胺水解产生的醛的亚胺或醛的选择性中的重要性。