Supramolecular Asymmetric Photochirogenesis with Biopolymers as Chiral Reaction Media

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H02289
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Polymer/Textile materials
• Research Institution: Tohoku University
• Principal Investigator: Wada Takehiko 東北大学, 多元物質科学研究所, 教授 (20220957)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 不斉光反応 / 不斉合成 / 有機光化学 / 超分子化学 / 生体高分子 / タンパク質 / 環境調和型 / 血清アルブミン

Outline of Final Research Achievements

In this study, we tried to construct a supramolecular asymmetric photochirogenesis (SMAP) as a novel asymmetric synthesis utilizing proteins as a chiral reaction media. Asymmetric photoreaction is attracting attention as a new eco-friendly method. The symmetric photodimerization of 2-anthracenecarboxylate (AC) utilizing human serum albumin (HSA) as chiral reaction media was investigated and found to obtain the chiral photodimers with high enantio excesses (ee) up to over 90%. Next, 2,6-anthracene dicarboxylate (AD) was employed as a photo substrate and investigated the SMAP of AD. An unexpected unique photodimer with naphthalene ring, which was never reported in solution synthesis, was obtained with almost 100%ee. Applied this unique reaction for photoreaction of AD with AC, fortunately, the AC-AD heterodimer was obtained with high ee up to 97%. Therefore, in this study, we have successfully demonstrated the SMAP as a powerful "environmentally friendly asymmetric synthesis method."

Free Research Field

機能性生体高分子科学ならびに光化学

Academic Significance and Societal Importance of the Research Achievements

新しい超分子光不斉反応(SMAP)系構築に向け、2,6-アントラセンジカルボン酸(AD)のHSA中でのSMAPを検討し、溶液系では得られないナフタレン環を有する特異的な構造の二量体を98％以上の光学収率で得られることを見出した。さらにタンパク質の利点を生かした夾雑系超分子不斉光反応の構築にも取組んだ。その結果、意外にもAC-ADヘテロ二量体が主生成物として97%を超える高いエナンチオ過剰率で得られた。これは、AC-AD間の光反応が動的に起きていると同時に、HSAからの極めて効率よいキラル情報伝搬が達成されていることを示す結果で、従来とは全く異なる超分子不斉光反応系概念の提案に成功した。