京都大学 · Chemistry
요시지 타케모토 교수의 연구실은 수소결합 기반 촉매화 기반의 고도로 선택적인 유기합성 반응 개발을 핵심으로 하며, 특히 우레아 및 티오우레아 유도체를 이용한 에너지 효율적인 비대칭 반응을 중심으로 연구를 전개하고 있습니다. 다양한 유기촉매(예: N-하이드로크시아미노, 카복실산 유도체, 할로겐 결합 촉매)를 활용해 반응 메커니즘의 규명과 새로운 반응 경로의 확립에도 기여하고 있습니다. 특히, 친환경적 조건에서의 고등급 선택성 반응 설계와 촉매의 다기능성 최적화에 초점을 맞추고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Hydrogen-bonding interaction plays a crucial role in the molecular recognition and activation processes of various biologically important reactions that are mediated by enzymes and antibodies in living organisms. Recently, it has been shown that a hydrogen-bonding donor can be used as a general acid catalyst for various types of reactions in organic chemistry. In this article, we describe enantioselective reactions catalyzed by urea and thiourea derivatives as general acid catalysts as well as d
We have developed several multifunctional thiourea catalysts bearing a tertiary amine or an 1,2-amino alcohol in expectation of their synchronous activation of a nucleophile and an electrophile through both acid-base and hydrogen-bonding interactions. From these studies, it was revealed that the weak acidity of thioureas compared with metallic Lewis acids could be overcome by this modification. The bifunctional aminothiourea could be used efficiently for a wide range of diastereoselective and en
Hydrogen-bond (HB)-donor catalysts that bear a 2-aminoquinazolin-4-(1H)-one or a 3-aminobenzothiadiazine-1,1-dioxide skeleton have been developed, and it has been shown that these catalyst motifs act similarly to other HB-donor catalysts such as thioureas. The highly enantioselective hydrazination of 1,3-dicarbonyl compounds was realized even at room temperature with up to 96% ee for 2-aminoquinazolin-4-(1H)-one-type catalysts, which were more effective than the corresponding urea and thiourea c
The NHC-catalyzed thioesterification of aromatic or aliphatic aldehydes with a range of thiols was developed in the presence of a stoichiometric amount of an organic oxidant. Among the oxidants examined, phenazine was shown to give the best results in terms of chemical yield and compatibility with thiols.
The umpolung alkylation of silyl enol ethers with an iodonium(III) ylide proceeds under mild conditions to afford various 1,4-dicarbonyl compounds in high yields in the presence of a halogen-bonding catalyst. Unlike typical transition-metal activation processes of such ylide precursors, which tend to proceed via carbenoid intermediates, experimental and computational studies indicate that halogen bonding (XB) between the XB donor catalyst and the iodonium ylide plays a crucial role in promoting
Carboxylic acids and their corresponding carboxylate anions are generally utilized as Brønsted acids/bases and oxygen nucleophiles in organic synthesis. However, a few asymmetric reactions have used carboxylic acids as electrophiles. Although chiral thioureas bearing both arylboronic acid and tertiary amine were found to promote the aza-Michael addition of BnONH<sub>2</sub> to α,β-unsaturated carboxylic acids with moderate to good enantioselectivities, the reaction mechanism remains to be clarif
