Development of Chiral Bronsted Acid Catalyst with Phosphinic Acid as Active Center

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05874
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Synthetic chemistry
• Research Institution: Institute for Molecular Science
• Principal Investigator: MOMIYAMA Norie 分子科学研究所, 生命・錯体分子科学研究領域, 准教授 (80447127)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 有機分子触媒

Outline of Final Research Achievements

Catalytic asymmetric synthesis using a chiral Bronsted acid catalyst has attracted attention in recent years because it is an environmentally friendly synthetic process without the use of rare metal elements. However, the acidic functional group as the active centers has been still limited; therefore, newly design concept of chiral Bronsted acid is one of important objectives to expand the generality of chiral Bronsted acid catalysis. To this end, we designed and synthesized a new chiral Bronsted acid catalyst with phosphinic acid as an active center of a new acidic functional group. We successfully synthesized the desired chiral phosphinic-phosphoric acid catalyst. Furthermore, we revealed that chiral phosphoric acid-phosphoric acid catalyst was able to facilitate the enantioselective hetero Diels-Alder reaction of glyoxal hydrate with siloxydiene to give the desired cyclized product with moderate enantioselectivity.

Free Research Field

有機合成化学

Academic Significance and Societal Importance of the Research Achievements

本研究は、触媒分子内のナフチル骨格にホスフィン酸を、フェニルーナフチル骨格に環状の酸性官能基を導入することで、１）ホスフィン酸を触媒活性中心として活用、２）リン原子上の中心不斉を活用、３）リン原子上の置換基効果を活用、４）水素結合により制御された動的軸不斉を活用することが可能となり、単一の酸性官能基のみでは得られなかった触媒活性と不斉環境を実現した。その結果、これまでに収率や立体選択性の獲得が困難であった水和物を用いる触媒的不斉反応において、立体選択性を獲得することができた。本研究により、異なる酸性官能基を組み合わせる触媒分子設計の可能性を示唆した点において、学術的意義が大きい。