Reversible Photoisomerization in a Ru cis -Dihydride Catalyst Accessed through Atypical Metal–Ligand Cooperative H 2 Activation: Photoenhanced Acceptorless Alcohol Dehydrogenation
Reversible Photoisomerization in a Ru cis -Dihydride Catalyst Accessed through Atypical Metal–Ligand Cooperative H 2 Activation: Photoenhanced Acceptorless Alcohol Dehydrogenation
复制标题
通过非典型金属配体协同 H 2 活化实现 Ru 顺式二氢化物催化剂中的可逆光异构化：光增强无受体醇脱氢
DOI：
10.1021/acs.organomet.1c00648
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发表时间：
2022
期刊：
影响因子：
2.8
通讯作者：
Lacy, David C.
中科院分区：
文献类型：
--
作者：
Fanara, Paul M.;Vigneswaran, Vipulan;Gunasekera, Parami S.;MacMillan, Samantha N.;Lacy, David C.
吡啶衍生的钳形钌络合物的脱卤化氢通常导致脱芳构化的部分，例如在Milstein的PNN-Ru（CO）（Cl）（H）（1 Py）催化剂中。因此，我们惊讶地发现，在[{LutP}Ru（CO）（Cl）（H）（PPh 3）]（1）的脱卤化氢后，在卢替啶衍生的双齿类似物[{LutP′}Ru（CO）（H）（PPh 3）]（2）中，而不是脱芳构化的化合物中，存在芳构化的κ3-N，C，P结合模式。2与H2的反应导致形成顺式二氢化物[{LutP}Ru（CO）（H）2（PPh 3）]（3），标记研究证实了协同金属配体活化。3表现出可逆的光异构化，在辐照下形成另一个顺式二氢化物异构体（4）。利用4对配体取代的不稳定性来证明通过无受体醇脱氢的光增强的H2生产。标记的研究牵连金属配体合作（MLC）过程中的光催化反应，但他们似乎是偏离路径的过程的基础上，我们的机制研究的系统。后者强调，芳构化/脱芳构化可能不是必要的受体无转换，这是一般与一些当代研究类似的钌催化剂。
Dehydrohalogenation of pyridine-derived pincer ruthenium complexes often leads to dearomatized moieties, such as in Milstein’s PNN-Ru(CO)(Cl)(H) (1Py) catalyst. Thus, we were surprised to find an aromatized κ3-N,C,Pbinding mode in the lutidine-derived bidentate analogue [{LutP′}Ru(CO)(H)(PPh3)] (2), instead of a dearomatized compound, upon dehydrohalogenation of [{LutP}Ru(CO)(Cl)(H)(PPh3)] (1). The reaction of2with H2results in the formation of thecis-dihydride [{LutP}Ru(CO)(H)2(PPh3)] (3), and labeling studies confirm cooperative metal–ligand activation.3exhibits reversible photoisomerization, forming anothercis-dihydride isomer (4) upon irradiation. The lability of4toward ligand substitution was leveraged to demonstrate photoenhanced H2production via acceptorless alcohol dehydrogenation. Labeling studies implicate metal–ligand cooperative (MLC) processes during the photocatalytic reaction, but they appear to be off-path processes on the basis of our mechanistic study of the system. The latter emphasizes that aromatization/dearomatization may not be necessary for acceptorless transformations, which is generally consistent with several contemporary studies on analogous Ru catalysts.