New Developments in Non-Planar Conjugated Molecules Opened by Multiple Helicenes

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01983
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 33020:Synthetic organic chemistry-related
• Research Institution: Osaka Prefecture University
• Principal Investigator: Kamikawa Ken 大阪府立大学, 理学(系)研究科(研究院), 教授 (40316021)
• Co-Investigator(Kenkyū-buntansha): 宮原 郁子 大阪市立大学, 大学院理学研究科, 准教授 (40271176) ; 津留崎 陽大 大阪府立大学, 理学(系)研究科(研究院), 助教 (40623848)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: ヘリセン

Outline of Final Research Achievements

We have synthesized [5]helicenyl arene precursors and investigated their catalytic asymmetric synthesis of triple helicenes by Pd-catalyzed cross [2+2+2] cyclotrimerization with dimethyl acetylenedicarboxylate. We investigated the catalytic asymmetric synthesis of triple helixenes by Pd-catalyzed crossed [2+2+2] trimerization with dimethyl azaheric acid. Among various asymmetric ligands, (S)-QUINAP gave triple helixenes in 49% yield and 96% enantioselectivity. We also synthesized azahelicene precursors and subsequently carried out a double dehydrogenative C-H coupling reaction in the presence of Pd catalyst. As a result, we succeeded in synthesizing the desired S-shaped diaza[10]helicene as a single diastereomer in 90% yield.

Free Research Field

有機合成化学

Academic Significance and Societal Importance of the Research Achievements

本研究成果は、近年発展の目覚ましい多重ヘリセンの化学の進展に大いに寄与するものである。本研究で初めて合成が達成された光学活性三重ヘリセンやS字型ジアザヘリセンなどの合成法、構造、および物性など、新たに得られた基礎的知見が加わったことによる学術的意義は大きい。