Welcome to the Named Reactions category, where we explore the significant transformations in organic chemistry that bear the names of renowned chemists. Dive into the rich history and fundamental mechanisms behind reactions such as the Grignard reaction, Diels-Alder reaction, and Heck reaction, among others. Uncover the applications, limitations, and synthetic utility of these named reactions in organic synthesis. Discover how these reactions have shaped the field of organic chemistry and continue to inspire innovation. Embark on a journey through the world of named reactions and unlock the secrets of their chemical transformations.
What is Wolff rearrangement? The Wolff rearrangement is a chemical reaction that involves the conversion of diazoketones into ketenes. This reaction can be carried out using thermal, photochemical, or catalytic methods. The Wolff rearrangement is a crucial step in the Arndt-Eistert synthesis, a widely used organic chemical reaction that is used to elongate the carbon … Read more
What is Westphalen-Lettré rearrangement? The Westphalen-Lettré rearrangement refers to a chemical reaction that involves the dehydration of derivatives of 5-hydroxycholesterol, along with the migration of the C-10 to C-5 methyl group in compounds containing a β-substituent at the C-6 position. References Westphalen, T. (1915), Über die Einwirkung von Benzopersäure auf Cholesterin. [On the effect of … Read more
What is Wessely-Moser rearrangement? The Wessely-Moser rearrangement is a chemical reaction that is specifically performed on flavones and flavanones containing a 5-hydroxyl group. During the Wessely-Moser rearrangement, the heterocyclic ring undergoes fission and the resulting intermediate diaroylmethanes subsequently reclose in the opposite direction. References Wessely, F., Moser, G.H. Synthese und Konstitution des Skutellareins. [Synthesis and constitution … Read more
What are benzidine and semidine rearrangements? The acid-catalyzed rearrangement of hydrazobenzenes to 4,4′-diaminobiphenyls is referred to as the Benzidine rearrangement. Additionally, the semidine rearrangement occurs when a para substituent is present on the hydrazobenzene, resulting in the formation of p-aminodiphenylamine as the preferred product. These rearrangements are collectively known as the Zinin rearrangement, named after … Read more
What is benzilic acid rearrangement? The benzilic acid rearrangement, also known as the benzil-benzilic acid rearrangement, is a chemical reaction that occurs when benzil is treated with a base. The benzilic acid rearrangement involves the migration of a phenyl group, leading to the formation of benzylic acid. It’s worth noting that this type of rearrangement … Read more
What is Borsche-Drechsel cyclization? The Borsche-Drechsel cyclization is a chemical process that involves the transformation of cyclohexanone phenylhydrazone into tetrahydrocarbazole through an acid-catalyzed rearrangement. This rearrangement is followed by an oxidation step, resulting in the formation of carbazole. References Drechsel, E. (1888), Ueber Elektrolyse des Phenols mit Wechselströmen. [On the electrolysis of phenol with alternating … Read more
What is Algar-Flynn-Oyamada reaction? In 1934, the synthesis of flavones through oxidative cyclization of 2-oxychalcones with hydrogen peroxide under alkaline conditions was first reported by Algar and Flynn, and concurrently by Oyamada. This reaction is commonly known as the Algar-Flynn-Oyamada reaction, and has been referred to by several other names such as the Algar-Flynn oxidation, … Read more
What is Baker-Venkataraman rearrangement? The Baker-Venkataraman rearrangement is a rearrangement of o-acyloxyketones that occurs in the presence of a base, resulting in the production of β-diketones. These compounds are crucial intermediates in the synthesis of chromones and flavones. References W. Baker, “322. Molecular rearrangement of some o-acyloxyacetophenones and the mechanism of the production of 3-acylchromones” … Read more
What is aza-Claisen rearrangement? The aza-Claisen rearrangement is a specific variation of Claisen rearrangement and Belluš-Claisen rearrangement that involves the conversion of allylenamines and allylamides into γ,δ-unsaturated imines. While typically requiring high temperatures to proceed, this rearrangement can be conducted at lower temperatures when a Lewis acid is included or when transforming an amide enolate. Interestingly, … Read more
What is Barton reaction? The Barton reaction, alternatively referred to as the Barton nitrite ester reaction, involves the transformation of a nitrite ester into a γ-oximino alcohol. This reaction occurs through a photolytic process that initiates the homolytic cleavage of a nitrogen-oxygen bond, subsequently resulting in hydrogen abstraction. References D.H.R. Barton, J.M. Beaton, L.E. Geller, … Read more
