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Mechanistic study of C-H bond activation by O-2 on negatively charged Au clusters : alpha,beta-dehydrogenation of 1-methyl-4-piperidone by supported Au catalysts dagger
| Title: | Mechanistic study of C-H bond activation by O-2 on negatively charged Au clusters : alpha,beta-dehydrogenation of 1-methyl-4-piperidone by supported Au catalysts dagger |
| Authors: | Miyazaki, Ray Browse this author | | Jin, Xiongjie Browse this author →KAKEN DB | | Yoshii, Daichi Browse this author | | Yatabe, Takafumi Browse this author →KAKEN DB | | Yabe, Tomohiro Browse this author →KAKEN DB | | Mizuno, Noritaka Browse this author →KAKEN DB | | Yamaguchi, Kazuya Browse this author →KAKEN DB | | Hasegawa, Jun-ya Browse this author →KAKEN DB |
| Issue Date: | 21-Mar-2021 |
| Publisher: | Royal Society of Chemistry |
| Journal Title: | Catalysis science and technology |
| Volume: | 11 |
| Issue: | 10 |
| Start Page: | 3333 |
| End Page: | 3346 |
| Publisher DOI: | 10.1039/d1cy00178g |
| Abstract: | Au nanoparticles supported on the manganese oxide octahedral molecular sieve OMS-2 can efficiently catalyze alpha,beta-dehydrogenation of beta-N-substituted saturated ketones using O-2 as the terminal oxidant. However, despite the utility of this reaction, the active sites and the reaction mechanism remain unclear. Here, the reaction mechanism for the Au/OMS-2-catalyzed aerobic alpha,beta-dehydrogenation of 1-methyl-4-piperidone was investigated mainly by using density functional theory (DFT) calculations. From control experiments under various reaction conditions, we found that O-2 plays an important role in the alpha,beta-dehydrogenation over Au nanoparticles. Thus, we attempted to clarify the mechanism for the alpha,beta-dehydrogenation of 1-methyl-4-piperidone on Au nanoparticle catalysts by DFT calculations using Au cluster models. The reaction was found to cleave the C-H-alpha and C-H-beta bonds in that order. An O-2 molecule adsorbed on the negatively charged Au cluster caused by charge transfer from OMS-2 was found to be sufficiently activated to abstract the H-alpha atom in the 1-methyl-4-piperidone substrate. This indirect H-alpha abstraction by the activated O-2 was energetically more favorable than direct H-alpha abstraction by the Au cluster. The subsequent H-beta abstraction was found to be promoted by adsorbed oxygen species (i.e., HOO, OH, and O) formed after the H-alpha abstraction. The reaction mechanism proposed in this study provides general insight into the aerobic C-H bond activation by supported Au catalysts. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/84728 |
| Appears in Collections: | 触媒科学研究所 (Institute for Catalysis) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 長谷川 淳也
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