유기화학실험2 prelab_ Conjugate (Michael) Addition to a, b unsaturated Carbonyl

문서 내 토픽

1. Michael Addition

Michael addition은 nucleophilic enol anion이 unsaturated carbonyl compound와 반응하여 일어나는 conjugation 첨가 반응입니다. 이 반응은 acidity가 클수록, 입체장애가 적을수록 빠르게 일어나며, 염기가 촉매로 작용하여 소량만 쓰이고 가역적인 반응입니다. 또한 pi bond 대신 새로운 C-C single bond가 형성되는 것에서 반응이 유도됩니다.
2. 1,2-Addition vs 1,4-Addition

실험 A에서는 maleic anhydride가 aniline과 acetic acid와 반응하여 maleanilic acid를 형성하는 1,2-addition이 일어납니다. 반면 실험 C에서는 N-phenylmaleimide가 aniline과 acetic acid와 반응하여 1-Phenyl-3-phenylaminopyrrolidine-2,5-dione을 형성하는 1,4-addition이 일어납니다. 이는 maleic anhydride가 N-phenylmaleimide보다 electrophilic하고 good leaving group을 갖고 있으며, kinetic control과 thermodynamic control의 차이 때문입니다.
3. 실험 A: Maleanilic Acid 합성

실험 A에서는 maleic anhydride, aniline, acetic acid를 반응시켜 maleanilic acid를 합성합니다. 이 반응은 1,2-addition으로 진행되며, 수득량은 약 5.85g, 녹는점은 202°C로 예상됩니다.
4. 실험 B: N-Phenylmaleimide 합성

실험 B에서는 실험 A에서 얻은 maleanilic acid, anhydrous sodium acetate, acetic anhydride를 반응시켜 N-phenylmaleimide를 합성합니다. 수득량은 약 3.169g, 녹는점은 85°C로 예상됩니다.
5. 실험 C: 1-Phenyl-3-phenylaminopyrrolidine-2,5-dione 합성

실험 C에서는 N-phenylmaleimide, aniline, acetic acid를 반응시켜 1-Phenyl-3-phenylaminopyrrolidine-2,5-dione을 합성합니다. 이 반응은 Michael reaction, 1,4-addition으로 진행되며, 수득량은 약 1.598g, 녹는점은 215°C로 예상됩니다.

Easy AI와 토픽 톺아보기

1. Michael Addition

The Michael addition reaction is an important carbon-carbon bond forming reaction in organic chemistry. It involves the nucleophilic addition of a carbanion or enolate to an α,β-unsaturated carbonyl compound, resulting in the formation of a new carbon-carbon bond. This reaction is widely used in the synthesis of various organic compounds, including pharmaceuticals, natural products, and other complex molecules. The Michael addition is a powerful tool in the hands of organic chemists, allowing them to construct complex molecular frameworks efficiently and selectively. Understanding the mechanism, scope, and limitations of this reaction is crucial for designing effective synthetic strategies. Overall, the Michael addition is a versatile and valuable reaction that continues to play a significant role in modern organic synthesis.
2. 1,2-Addition vs 1,4-Addition

The choice between 1,2-addition and 1,4-addition in organic reactions is an important consideration for synthetic chemists. 1,2-Addition involves the nucleophilic addition of a reagent to the carbonyl carbon of an α,β-unsaturated carbonyl compound, while 1,4-addition (also known as the Michael addition) involves the nucleophilic addition to the β-carbon of the same system. The factors that influence the selectivity between these two pathways include the nature of the nucleophile, the substituents on the α,β-unsaturated carbonyl compound, the reaction conditions, and the desired product. Understanding the factors that govern the 1,2- versus 1,4-addition selectivity is crucial for designing efficient and selective synthetic routes. Careful consideration of the reaction parameters and the use of appropriate directing groups or catalysts can often be used to control the selectivity and obtain the desired product. The ability to predict and control the addition pathway is a valuable skill for organic chemists working on the synthesis of complex molecules.
3. Experiment B: N-Phenylmaleimide Synthesis

The synthesis of N-phenylmaleimide is an important organic reaction that involves the cyclization of maleanilic acid, a precursor obtained from the reaction of maleic anhydride and aniline. This reaction is a key step in the preparation of various maleimide-based compounds, which have numerous applications in organic synthesis, polymer chemistry, and bioconjugation. The experimental procedure typically involves the heating of maleanilic acid in the presence of an acid catalyst, such as acetic acid, to facilitate the cyclization and eliminate water, forming the desired N-phenylmaleimide product. The success of this experiment depends on the student's understanding of the reaction mechanism, their ability to control the reaction conditions, and their skills in product purification and characterization. Mastering the synthesis of N-phenylmaleimide can provide valuable insights into the reactivity of maleanilic acid, the factors that influence the cyclization process, and the importance of this class of compounds in organic chemistry and related fields.