Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Applied Catalysis A General  

β-Hydroxy β-methylbutyric acid (HMB) is expected as a promising therapeutic agent or a supplement. For industrial production of HMB, Pt-catalyzed aerobic oxidation of isoprene glycol is a potent synthetic method. However, the previous report using Pt-Bi catalyst supported on active carbon suffered from low tolerance to high substrate concentration conditions, which leads to low volumetric productivity. Herein, we report aerobic oxidation of isoprene glycol using Pt-Bi catalysts supported on ZrO<inf>2</inf> or TiO<inf>2</inf>, showing high tolerance to the high substrate concentration conditions. In addition, these catalysts exhibited high recyclability. Scanning transmission electron microscopy analyses suggested the Pt-Bi species supported on ZrO<inf>2</inf> or TiO<inf>2</inf> are less likely to aggregate than those supported on activated carbon. Additionally, these metal oxides supported catalysts showed lower metal leaching than the carbon supported catalysts. Besides, the results of the various control experiments indicated the prevention of dehydration of an aldehyde intermediate is important for further improvement.

DOI： 10.1016/j.apcata.2022.118781

Web of Science

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACS Catalysis  

Herein, we report a heterogeneous cobalt-catalyzed H<inf>2</inf>S-reagent-free synthetic method for 1,2-bis(2,4,4-trimethylpentan-2-yl)polysulfanes, which have been used as extreme-pressure additives in the field of tribology and have been produced worldwide in the tens of thousands of tonnes per year. The current industrial synthetic processes typically use hydrogen sulfide as the reductant, but improvements are needed in terms of the toxicity and the cost associated with safety control. The present reaction with Co<inf>3</inf>O<inf>4</inf> and Na-X zeolite as catalysts provides the corresponding polysulfanes with three to eight sulfur atoms from diisobutylene, hydrogen, and elemental sulfur in up to 88% yield under neat reaction conditions. Experimental and density functional theory (DFT) mechanistic investigations provide insights into the roles of Na-X zeolite and cobalt catalysts. The DFT calculations suggest that heterolytic H<inf>2</inf> activation with cobalt polysulfide species and subsequent protonation of alkenes and the C-S bond formation take place in a single step by a terminal SSH group in the cobalt polysulfide species, which provides a reasonable interpretation of the observed Markovnikov selectivity.

DOI： 10.1021/acscatal.3c03545

Web of Science

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/marc.202300155

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/cctc.202101092

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1246/cl.180031

Presentation type：Poster presentation  

Presentation type：Oral presentation (general)  

Presentation type：Poster presentation  

Presentation type：Oral presentation (general)