Claisen-Schmidt Condensation

The Claisen-Schmidt condensation is a reaction in organic chemistry that involves the condensation of an aldehyde or ketone that has an α-hydrogen with an aromatic carbonyl compound, resulting in the formation of an α,β-unsaturated carbonyl compound. This reaction is a specific type of aldol condensation and is named after Rainer Ludwig Claisen and J. Gustav Schmidt, who independently reported on this topic in the late 19th century[1].

An example of a product from the Claisen-Schmidt condensation is dibenzylideneacetone, which is synthesized from acetone and benzaldehyde. The reaction proceeds through the formation of an enolate ion from the aldehyde or ketone with an α-hydrogen, which then attacks the aromatic carbonyl compound. The initial product is a β-hydroxycarbonyl compound that typically undergoes dehydration to yield an α,β-unsaturated carbonyl compound[1][11].

The Claisen-Schmidt condensation is an example of a crossed aldol process, where the enolizable nucleophilic carbonyl compound reacts with the electrophilic carbonyl compound. Quantitative yields have been reported in the absence of solvent, and the reaction is often carried out under basic conditions[1].

The reaction mechanism involves the removal of an α-proton from the nucleophilic carbonyl compound to form an enolate ion, which then attacks the electrophilic carbonyl compound. The product of this addition is a β-hydroxycarbonyl compound that can dehydrate to form the final α,β-unsaturated carbonyl compound[4][11].

The Claisen-Schmidt condensation is important in organic synthesis and biochemistry for forming carbon-carbon bonds and constructing complex molecules. It is also used in the synthesis of various compounds, including those with applications such as ultraviolet blockers in sunscreen preparations[11].

Citations:

[1] https://en.wikipedia.org/wiki/Claisen%E2%80%93Schmidt_condensation

[2] https://www.youtube.com/watch?v=LoU048BKMkk

[3] https://www.sciencedirect.com/science/article/abs/pii/S0040402021008772

[4] https://byjus.com/chemistry/claisen-condensation-mechanism/

[5] https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Book:_Organic_Chemistry_with_a_Biological_Emphasis_v2.0_(Soderberg)/13:_Reactions_at_the_-Carbon_Part_II/13.04:_Claisen_Condensation

[6] https://wwpw.youtube.com/watch?v=-YpF4kbrQl8

[7] https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_(Morsch_et_al.)/23:_Carbonyl_Condensation_Reactions/23.07:_The_Claisen_Condensation_Reaction

[8] https://www.chemistrysteps.com/claisen-condensation-the-mechanism-of-ester-enolates/

[9] https://www.pearson.com/channels/organic-chemistry/learn/johnny/condensation-chemistry/claisen-schmidt-condensation

[10] https://en.wikipedia.org/wiki/Claisen_condensation

[11] https://praxilabs.com/en/3d-simulations/claisen-schmidt-reaction

[12] https://www.cs.gordon.edu/courses/organic/salem/claisenSchmidt.html

[13] https://www.youtube.com/watch?v=3M4c21PqoMU

[14] https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/claisen-condensation

[15] https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Reactions/Organic_Reactions/Claisen_Condensation

[16] https://www.masterorganicchemistry.com/2020/09/14/claisen-condensation-and-dieckmann-condensation/