Development of New Method for Synthesis of Heterocyclic Compounds Utilizing Cycloaddition Reactions Catalyzed by Bronsted Base

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05680
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Organic chemistry
• Research Institution: Tohoku University
• Principal Investigator: Kondoh Azusa 東北大学, 理学研究科, 助教 (30645544)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 有機塩基触媒 / 不斉触媒反応 / 環化付加反応 / 複素間骨格構築 / 付加反応 / アセタール合成 / 不斉合成

Outline of Final Research Achievements

With the aim of establishing the novel synthetic methods of multi-substituted five-membered heterocyclic compounds in a highly stereoselective manner, we investigated the formal [3+2] cycloaddition reactions of three-membered ring compounds, such as epoxides, aziridines, and cyclopropanes, with unsaturated compounds on the basis of our original methodology utilizing Bronsted base catalysis. As a result, we successfully developed a novel enantioselective formal [3+2] cycloaddition reaction of β,γ-epoxysulfones with imines under Bronsted base catalysis. The　chiral bis(guanidino)iminophosphorane as a chiral organosuperbase catalyst enabled the enantioselective reaction, owing to its strong basicity and high stereocontrolling ability, to provide enantioenriched 1,3-oxazolidines, which are useful building blocks in organic synthesis, in a highly diastereo- and enantioselective manner.

Free Research Field

有機合成化学

Academic Significance and Societal Importance of the Research Achievements

本研究では、三員環化合物と不飽和化合物の形式的不斉[3+2]環化付加反応に初めてブレンステッド塩基触媒を適用することに成功した。この成果は光学活性五員複素環化合物の合成における新たな方法論を提供するものである。五員複素環化合物の遍在性および有機合成におけるビルディングブロックとしての有用性を鑑みると、複雑化合物の合成戦略に新たな指針を与えるものとして、大きな意義がある。また、ブレンステッド塩基を用いる触媒的分子変換の新たな可能性を示した点でも意義がある。