Kyushu University Academic Staff Educational and Research Activities Database
List of Reports
TATSUYA UCHIDA Last modified date:2019.06.14

Associate Professor / Division for Arts and Science / Division for Experimental Natural Science / Faculty of Arts and Science


Reports
1. RYO IRIE, TATSUYA UCHIDA, KAZUHIRO MATSUMOTO, Katsuki Catalysts for Asymmetric Oxidation: Design Concepts, Serendipities for Breakthroughs, and Applications, Chemical Letters, 2015.08.
2. TATSUYA UCHIDA, Tsutomu Katsuki, Asymmetric nitrene transfer reactions: sulfimidation, aziridination and C-h amination using azide compounds as nitrene precursors, The Chemical Record, 2014.02, Nitrogen functional groups are found in many biologically active compounds and their stereochemistry has a profound effect on biological activity. Nitrene transfer reactions such as aziridination, C-H bond amination, and sulfimidation are useful methods for introducing nitrogen functional groups, and the enantiocontrol of the reactions has been extensively investigated. Although high enantioselectivity has been achieved, most of the reactions use (N-arylsulfonylimino)phenyliodinane, which co-produces iodobenzene, as a nitrene precursor and have a low atom economy. Azide compounds, which give nitrene species by releasing nitrogen, are ideal precursors but rather stable. Their decomposition needs UV irradiation, heating in the presence of a metal complex, or Lewis acid treatment. The examples of previous azide decomposition prompted us to examine Lewis acid and low-valent transition-metal complexes as catalysts for azide decomposition. Thus, we designed new ruthenium complexes that are composed of a low-valent Ru(II) ion, apical CO ligand, and an asymmetry-inducing salen ligand. With these ruthenium complexes and azides, we have achieved highly enantioselective nitrene transfer reactions under mild conditions. Recently, iridium-salen complexes were added to our toolbox..
3. TATSUYA UCHIDA, Tsutomu Katsuki, Green Asymmetric Oxidation Using Air as Oxidant, Synthetic Organic Chemistry Japan, 2013.11, Nitrogen functional groups are found in many biologically active compounds and their stereochemistry has a profound effect on biological activity. Nitrene transfer reactions such as aziridination, C-H bond amination, and sulfimidation are useful methods for introducing nitrogen functional groups, and the enantiocontrol of the reactions has been extensively investigated. Although high enantioselectivity has been achieved, most of the reactions use (N-arylsulfonylimino)phenyliodinane, which co-produces iodobenzene, as a nitrene precursor and have a low atom economy. Azide compounds, which give We found that (NO)- and (aqua)ruthenium-salen complexes are efficient catalysts for the asymmetric aerobic oxygen atom transfer reactions such as epoxidation and sulfoxidation at ambient temperature. (NO)ruthenium-salen complexes 2 and 3 could catalyze oxidation of sulfides and the epoxidation of conjugated olefins with good to high enantioselectivity using dioxygen as oxidant, albeit under visible light-irradiation, respectively. On the other hand, (aqua)ruthenium-salen complex 5 was found to catalyze highly enantioselective epoxidation in air even without irradiation. Although the mechanism of this ruthenium-catalyzed aerobic oxidation has not been completely elucidated, water that is bound to the ruthenium ion has been considered to play a critical role in proton coupled electron transfer, a key step for oxygen activation, and to be regenerated via oxo-hydroxo tautomerization. We also found that (di-μ-hydroxo)iron-salan complexes catalyzes asymmetric dehydrogenative oxidation reactions such as 2-naphthol coupling, alcohol oxidation, and dearomatization, using air as oxidant..
4. Uchida Tatsuya, Katsuki Tsutomu, a-Diazoacetates as Carbene Precursors: Metallosalen-Catalyzed Asymmetric Cyclopropanation, Synthesis, 2006(10), 1715-1723, 2006.03.