アミンとエーテルでケラートされたアリルリチウム反応剤-構造と動態
Hans J Reich1, Wayne S Goldenberg, Aaron W Sanders
1Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA. reich@chem.wisc.edu
Journal of the American Chemical Society
|March 20, 2003
まとめ
フェニルリチウム反応剤におけるケレーションは,集積に影響する. エーテル・ケラートはTHFと競合し,アミン・ケラートは限られた相互作用を示し,重要な二重体形成と特定の構造的洞察につながる.
科学分野:
- 有機金属化学 有機金属化学
- オーガニック・シンセシス オーガニック・シンセシス
- スペクトル顕微鏡検査です.
背景:
- フェニルリチウム反応剤は,有機合成において極めて重要です.
- 彼らの集積状態を理解することは,反応性を制御する鍵です.
- 整形置換剤によるケレーションは,反応剤の振る舞いを大幅に変化させることができます.
研究 の 目的:
- フェニルリチウム集積に対するケラートアミンおよびエーテル置換物の影響を調査する.
- 最先端のスペクトロスコーピテクニックを用いてケレーションの構造的影響を解明する.
- 異なるリングサイズとヘテロアトム (N対O) のケレーティング能力を比較する.
主な方法:
- 温度変数6Liと13Cの核磁共振 (NMR) スペクトロスコーピー.
- 6Liおよび15Nイソトープのラベル付け研究.
- テトラヒドロフラン (THF) と1,1,4,7,10-ペンタメチルエチレントリアミン (PMDTA) を含む溶媒添加物の効果の調査.
主要な成果:
- 5環および6環エーテルケラート (化合物4,5) は,THFと効果的に競合する.
- 6環アミンケラート (化合物2) はTHFとの競合が弱く,7環アミンケラート (化合物3) はTHFとの競合がない.
- シェラ化フェニルリチウム反応剤は,モデル化合物と比較して,40から20万以上の因数で,著しく強化された二分化を示す.
- 同位体で標識された化合物のNMRカップリングを通じて,2-(2-ジメチラミノエチル) フェニルリチウム (2) に対して,特定のA型ダイマー構造が割り当てられました.
- 化合物2のモノマーは,検出可能なケラ化反応は示さないが,そのジメルはケラ化反応を示している.
- 2-(メトキシメチル) フェニルリチウム (4) は,開いた二重体と五重座標単体を形成する.
- ほとんどのリチウム反応剤は,PMDTA.とモノメール,非ケラ化添加物を形成する.
結論:
- 整形置換剤によるケレーションは,フェニルリチウム反応剤の二酸化を強く促進する.
- エーテル置換剤は,THFとの競争において,アミン置換剤よりも効果的なケラート剤である.
- ケラートジメルの特定の構造的割り当ては可能であり,集積行動に関する洞察を提供します.
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