メソ・ラクチドからイソタクティック・ポリラクチドへ:B/Nルイス対によるエピメリゼーションと有機触媒による運動解像度
Jian-Bo Zhu1, Eugene Y-X Chen1
1Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523-1872, United States.
Journal of the American Chemical Society
|September 22, 2015
まとめ
ルイス酸塩対はメソラクチド (LA) を急速にラセミックLAに変換する. このラセミックなLAは,ポリー ((L-ラクチド) にポリメリゼーションされ,新しいキラル触媒を用いて,高ステレオ選択性を持つD-LAを光学的に分解する.
科学分野:
- 有機化学
- ポリマー科学
- カタリシス
背景:
- メソラクチド (LA) エピメリゼーションは,エナティオメリックに純粋なラクチドイソマーにアクセスするために不可欠です.
- ラクチドのステレオ選択的ポリメリゼーションのための効率的な触媒の開発は,継続的な課題です.
研究 の 目的:
- メソラクチドの急速なエピメリゼーションのための新しい触媒を開発する.
- ラセミック・ラクチドの高度にステレオ選択的運動ポリメリゼーションを達成する.
- エピメリゼーションとポリメリゼーションを1つのポットプロセスに組み合わせる
主な方法:
- メソラクチドエピメリゼーションのためにB/Nルイスペアを使用した.
- β-イソクプリデイン・コア,チオウレア,BINAMを組み込んだ二機能キラル触媒を設計した.
- エピメリ化乳酸の運動ポリメリゼーションを行った.
主要な成果:
- メソラクチドをラセミックラクチドに量的にエピメリゼーションした.
- 高ステレオ選択性 (k) /k (D) = 53) とエナティオメール過剰 (ee = 91%) を有するポリ (L) ラクチドと光学的に解明されたD-ラクチドが得られる.
- メソ-LAの直接変換のための成功したワンポットプロセスを実証した.
結論:
- B/N ルイスペアは,乳酸の急速なエピメリゼーションを効果的に触媒化する.
- この新しい二機能性キラル触媒は,高度にステレオ選択的な乳酸のポリメリゼーションを可能にします.
- クープリングされたワンポットプロセスは,メゾラクチド変換のための効率的な経路を提供します.
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