ヴィニルサイクロプロパンとパイシステムの [5 + 2] サイクル添加反応の非対称な触媒
Paul A Wender1, Lars O Haustedt, Jaehong Lim
1Department of Chemistry, Stanford University, Stanford, California 94305, USA. wenderp@stanford.edu
Journal of the American Chemical Society
|May 11, 2006
まとめ
研究者らは,金属触媒 [5 + 2] サイクロアディションのための高度に選択的なロジウム触媒を開発しました. これらの触媒は,ビニルcyclopropanes (VCPs) とpi-systemsを効率的に高エナティオメア過剰を持つ複雑な分子に変換します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- カタリシス カタリシス カタリシス
- アシンメトリック・シンセシス
背景:
- 金属触媒によるサイクル添加は,有機合成に不可欠である.
- ロジウム ((I) 複合体は,ビニルcyclopropanes (VCPs) とpi-systems.の [5 + 2]サイクル添加を触媒化することに有望であることが示されています.
- 以前の研究で,穏やかな条件下で動作するRh(I) 触媒が実証されました.
研究 の 目的:
- ロジウムで触媒化された [5 + 2] サイクル添加のためのキラル触媒を比較的に評価する.
- 望ましい触媒である[((R) -BINAP) Rh]+SbF6−の性能を,様々な基板で評価する.
- 反応選択性の予測モデルを開発する.
主な方法:
- 複数のキラルロジウム触媒のスクリーニング.
- 多様なビニルサイクロプロパンとパイシステム基板で最適化された触媒をテストする.
- キラルクロマトグラフィを用いたエナティオメア過剰 (ee) の分析.
- 選択性予測のための計算モデルの開発.
主要な成果:
- [5 + 2]サイクル添加のためにいくつかのキラル触媒が評価されました.
- 好ましい触媒である[R]-BINAP) Rh]+SbF6は,いくつかの基板組み合わせで高いエナチオ選択性 (>95% ee) を達成した.
- 基板の置換とテザーのタイプは,選択性に大きく影響した.
- 選択性の予測モデルが成功裏に開発されました.
結論:
- チラルロジウム触媒,特に[((R) -BINAP) Rh]+SbF6-は,高度にエナチオセレクティブの [5 + 2]サイクル添加を可能にします.
- 開発された予測モデルは,反応結果を理解し,制御するのに役立ちます.
- この研究は,非対称な金属触媒サイクロアディションの分野を前進させています.
さらに関連する動画
関連する概念動画
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Photochemical Electrocyclic Reactions: Stereochemistry
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Cycloaddition Reactions: Overview
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
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