Stork reaction

The Stork reaction , also known as the Stork enamine reaction , is a name reaction from the field of organic chemistry. It was named after the Belgian- born chemist Gilbert Stork and is a variant of the Michael addition . While in the Michael addition an enolation with α, β-unsaturated ketones or aldehydes is converted to 1,5-dicarbonyls , here instead of the enolation an enamine is used to substitute the ketone on the α-carbon.

Reaction mechanism

Presentation of the enamine

As a nucleophile, the amine attacks the carbonyl carbon atom of the ketone. The resulting alcoholate ion is protonated and the release of a proton by the protonated amine creates a neutral tetrahedral intermediate. Water is split off by renewed protonation. In the last step, the double bond of the enamine is then formed.

The remainder (R = primary he or secondary he alkyl group , allyl , benzyl , propargyl , CH₂CO₂R, CH₂CN) of the halogenated hydrocarbon is attached to the enamine. In an acidic hydrolysis , the pyrrolidine previously added during the enamine formation is split off again. The α-substituted ketone is formed by deprotonation.

variants

As a reactant of the enamines, for. B. oxiranes , acrylonitrile or 2,4-dinitrochlorobenzene can also be used.

literature

• Paula Y. Bruice: Organic Chemistry. Pearson Studium, 2007, p. 993, ISBN 978-3-8273-7190-4 .
• László Kürti , Barbara Czako: Strategic Applications of Named Reactions in Organic Synthesis, 2nd edition, Elsevier Academic Press, Amsterdam 2005, ISBN 978-0-12-369483-6