Catalytic Asymmetric Synthesis of Chiral Helicenes by Hydroarylation of VQM as a Key Reaction

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05514
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 33020:Synthetic organic chemistry-related
• Research Institution: Kumamoto University
• Principal Investigator: Irie Ryo 熊本大学, 大学院先端科学研究部(理), 教授 (70243889)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 不斉合成 / 塩基触媒 / アルキン / ヒドロアリール化 / 環化芳香化 / ヘテロヘリセン / 軸不斉化合物 / 螺旋不斉化合物

Outline of Final Research Achievements

Optically active π-conjugated molecules are expected to exhibit unique chiral properties, which has prompted studies on their efficient synthesis and applications as functional molecular materials. In this research, we successfully achieved the asymmetric synthesis of new chiral π-conjugated heterohelicenes with helical and axial chirality by using the catalytic enantioselective intramolecular hydroarylation of alkynes that have been recently developed by our group as the key reaction. The molecular structure and relative configuration of a derivative of the heterohelicenes in a racemic form was unambiguously determined by X-ray crystallography, based on which we were able to propose a plausible reaction mechanism and stereochemical course of the hydroarylation. Furthermore, we also revealed that the heterohelicenes thus obtained are promising chiral functional molecules.

Free Research Field

有機合成化学

Academic Significance and Societal Importance of the Research Achievements

捻れたπ共役系をもつヘリセンは，歪みエネルギーを内在している．分子歪みの小さい前駆体(基質)を歪みの大きなヘリセンに変換し，かつ，その過程で誘起される螺旋キラリティの立体化学制御を如何に達成するか？この学術的な「問い」は，不斉炭素原子を有するキラル化合物の不斉合成法が格段に進歩した今日においても極めて挑戦的である．また，ヘリセン類は特異なキラル物性を示すことから，そのキラル分子材料としての応用が期待される．本研究では，最近我々が開発に成功したアルキンの触媒的不斉分子内ヒドロアリール化を鍵反応として，新規キラルヘテロヘリセン類の不斉合成に成功するとともに，優れたキラル物性について明らかにした．