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The Claisen rearrangement is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. [1] The heating of an allyl vinyl ether will initiate a [3,3]-sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl, driven by exergonically favored carbonyl CO bond formation with Δ(Δ f H) ca. −25 kcal/mol (−100 kJ/mol).
The Claisen condensation is a carbon–carbon bond forming reaction that occurs between two esters or one ester and another carbonyl compound in the presence of a strong base. The reaction produces a β-keto ester or a β-diketone. [1] It is named after Rainer Ludwig Claisen, who first published his work on the reaction in 1887.
The Staudinger reduction is conducted in two steps. First phosphine imine-forming reaction is conducted involving treatment of the azide with the phosphine. The intermediate, e.g. triphenylphosphine phenylimide, is then subjected to hydrolysis to produce a phosphine oxide and an amine:
A pericyclic reaction is a type of reaction with multiple carbon–carbon bond making and breaking wherein the transition state of the molecule has a cyclic geometry, and the reaction progresses in a concerted fashion. Examples are hydride shifts. and the Claisen rearrangement: [5]
The most commonly studied reactions in this field are the 4π Staudinger β-lactam synthesis [10] and the 4π Nazarov reaction; asymmetric catalysis of both reactions have been controlled by use of a chiral auxiliary, and the Nazarov reaction has been performed catalytically using chiral Lewis acids, Brønsted acids and chiral amines. [11]
Tishchenko reaction, Tishchenko–Claisen reaction; Tollens reagent; Transfer hydrogenation; Trapp mixture; Transesterification; Traube purine synthesis; Truce–Smiles rearrangement; Tscherniac–Einhorn reaction; Tschitschibabin reaction; Tschugajeff reaction; Tsuji–Trost reaction; Tsuji–Wilkinson decarbonylation reaction; Twitchell ...
The Dieckmann condensation is the intramolecular chemical reaction of diesters with base to give β-keto esters. [1] It is named after the German chemist Walter Dieckmann (1869–1925). [2] [3] The equivalent intermolecular reaction is the Claisen condensation. Dieckmann condensations are highly effective routes to 5-, 6-, and 7-member rings ...
Often cross-coupling reactions require metal catalysts. One important reaction type is this: R−M + R'−X → R−R' + MX (R, R' = organic fragments, usually aryl; M = main group center such as Li or MgX; X = halide) These reactions are used to form carbon–carbon bonds but also carbon-heteroatom bonds.