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Nazarov Cyclization

(Nazarov Reaction)

Published Online: 15 SEP 2010

DOI: 10.1002/9780470638859.conrr452

Comprehensive Organic Name Reactions and Reagents

Comprehensive Organic Name Reactions and Reagents

How to Cite

2010. Nazarov Cyclization. Comprehensive Organic Name Reactions and Reagents. 452:2011–2016.

Publication History

  1. Published Online: 15 SEP 2010

Chemistry Terms

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Nazarov cyclization, or Nazarov reaction is an acid-promoted cationic pericyclic reaction that transforms a divinyl ketone into 2-cyclopentenone. This reaction undergoes a 4-π electrocyclic, conrotatory cyclization via a 3-oxy-pentadienylic cation and requires of strong Brønsted acid or Lewis acid. Many complicated Lewis acids have been used for this reaction. This reaction gives a thermodynamically favored cyclopentenone with more substituents. Alkoxy on a vinyl group, or the presence of a bridge-headed proton on the endocyclic intermediate facilitates the protic acid-promoted cyclization. Denmark has developed the directed Nazarov cyclization and Ichikawa has developed the other form to control the regiochemistry. The interrupted Nazarov reaction has also been developed to extend the reaction of the cationic endocyclic intermediate with carbon nucleophiles.


  • vinyl allenyl imine;
  • Lewis acid;
  • cyclopentenone;
  • silicon;
  • protic acid