主要なアリルアミンの直接置換は,硫酸塩酸塩と直接置換する
Xue-Song Wu1, Yan Chen, Man-Bo Li
1Joint Laboratory of Green Synthetic Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
Journal of the American Chemical Society
|August 30, 2012
まとめ
この研究は,原発性アリルアミンと硫酸塩からアリルシルフォンを生成するための新しいパラジウム触媒反応を導入しています. この方法は,地域とステレオ選択性の優れた制御を提供し,多様で光学的に純粋な製品を生み出します.
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
- 合成方法論 合成方法論
背景:
- アリル系スルフォンは,価値ある合成中間物質である.
- アリルアミンの直接的な機能化は依然として課題です.
- アシンメトリックアリルカルスルフォン合成のための既存の方法は,基板の範囲に制限があります.
研究 の 目的:
- アリル硫黄素の直接合成のための新しい触媒方法の開発.
- 主要アリルアミンの置換において,高い地域およびステレオ選択性を達成する.
- キラルアリル硫黄素の非対称合成のための基板の範囲を拡大する.
主な方法:
- 主要アリルアミンのNH(2) 群のパラジウム触媒による直接置換で,硫酸塩を用いる.
- 1,4-bis(diphenylphosphino) butane (dppb) リガンドを α-選択的置換のために利用した [Pd(allyl) Cl](2) 触媒.
- クイラルアミンとの非対称的な合成のために 1,1'-bi-2-naphthol (BINOL) リガンドを使用しています.
主要な成果:
- アリル系スルフォンの形成において,優れた地域およびステレオ選択性を達成した.
- 構造的に多様なアルリル硫黄素を合成し,優れたE選択性を持つ良好から優れた収穫量を得ました.
- 非対称性アリルアミンから,高光学純度で,エナティオメア余剰 (ee) の優れた保持率を有するキラルアリルアリルスルフォンを得ている.
結論:
- 開発された触媒システムは,α-枝分かれおよびα-キラルアリル硫黄素への効率的な経路を提供します.
- この方法は,非対称性アリル型電極の使用を可能にすることで,既存の非対称性戦略を補完します.
- この反応は,高いステレオ化学的制御を持つ複雑な分子を構築するための貴重なツールを提供します.
関連する概念動画
01:23Amines to Sulfonamides: The Hinsberg Test
The Hinsberg test is a method to identify primary, secondary and tertiary amines, named after its pioneer, Oscar Hinsberg. Here, amines are treated with benzenesulfonyl chloride, also known as the Hinsberg reagent, in the presence of an excess of aqueous base, followed by acidification. Based on the nature of the amines, different changes are observed.
Generally, a primary amine reacts with the Hinsberg reagent to produce an N-substituted benzenesulfonamide. The electron-withdrawing sulfonyl...
Generally, a primary amine reacts with the Hinsberg reagent to produce an N-substituted benzenesulfonamide. The electron-withdrawing sulfonyl...
01:07Acid Halides to Amides: Aminolysis
Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
02:26Preparation and Reactions of Sulfides
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
01:22Preparation of 1° Amines: Azide Synthesis
Direct alkylation of ammonia produces polyalkylated amines, along with a quaternary ammonium salt. To exclusively prepare primary amines, the azide synthesis method can be used.
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
01:30Preparation of Amines: Alkylation of Ammonia and Amines
Alkylation is one of the methods used to prepare amines. Direct alkylation of ammonia or a primary amine with an alkyl halide gives polyalkylated amines along with a quaternary ammonium salt through successive SN2 reactions. This process of making the quaternary salt through the direct alkylation method is called exhaustive alkylation.
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
01:28Preparation of 1° Amines: Gabriel Synthesis
Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...