The combined experimental/DFT computational study of RuH₂(CO)[Et₂NCH₂PyCH₂Pt-Bu₂] (2) suggests that this dihydride is the catalyst of the acceptorless alcohol dehydrogenation and ester hydrogenation reactions developed in the group of Milstein, whereas the corresponding alkoxide RuH(OR)(CO)[Et₂NCH₂PyCH₂Pt-Bu₂] (4) is an important reaction intermediate. A relatively fast equilibrium of dihydride 2 and ethanol with ethoxide 4 and H₂ was demonstrated by NMR experiments, as well as the proton exchanges occurring between the OH of ethanol, RuH, and the CH₂ groups of the PNN ligand backbone of 2 and 4. A detailed critical discussion of the previously proposed mechanisms with the Milstein catalyst is presented. This paper also reports the preparation of the osmium dihydride OsH₂(CO)[Et₂NCH₂PyCH₂Pt-Bu₂] (2-Os) and a comparative study of 2, 2-Os, and the Noyori-type osmium catalyst OsH₂(CO)[PyCH₂NHCH₂CH₂NHPt-Bu₂].

中文翻译：

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Milstein PNN钌配合物催化醇脱氢和酯还原的修正机理

期RuH的组合实验/ DFT计算研究₂（CO）[等₂ NCH ₂ PyCH ₂ P吨-Bu ₂ ]（2）表明，这二氢化是acceptorless醇脱氢和酯氢化反应的基团的中开发的催化剂米尔斯坦，而相应的醇盐期RuH（OR）（CO）[等₂ NCH ₂ PyCH ₂ P吨-Bu ₂ ]（4）是中间的重要反应。二酐2和乙醇与乙醇4和H _2的相对较快的平衡由NMR实验证明，以及乙醇的OH，RuH和PNN配体主链2和4的CH ₂基团之间发生的质子交换。提出了对先前提出的使用米尔斯坦催化剂的机理的详细的批判性讨论。本文还报道了锇二氢化OSH的制备₂（CO）[等₂ NCH ₂ PyCH ₂ P吨-Bu ₂ ]（2 -Os）和进行比较研究2，2 -Os，和野依型锇催化剂OsH ₂（CO）[PyCH ₂ NHCH₂ CH ₂ NHP t -Bu ₂ ]。