1,3-dipolar cycloaddition
1,3-Dipolar Cycloaddition is a term for certain chemical reactions in organic chemistry . These are cycloadditions in which a 1,3- dipolar molecule or fragment is involved. As a mesomeric-stabilized 1,3-dipole, ozone , azides , diazoalkanes, nitrile oxides, nitrile imines, nitrones etc. are added to alkenes or alkynes . The atom economy of the 1,3-dipolar cycloadditions is consistently excellent.
An example of a 1,3-dipolar cycloaddition is the Huisgen reaction. This reaction was known earlier, but only Rolf Huisgen was able to elucidate the exact mechanism based on his systematic studies of the 1,3-dipolar cycloaddition. The reaction is usually carried out with an azide and an alkyne . If it takes place under copper catalysis, this represents the first and most prominent representative of the so-called click chemistry , CuAAC (copper-catalyzed azide-alkyne cycloaddition).
A double 1,3-dipolar cycloaddition is the ozonolysis : this is only the 1,3-dipole ozone and, after the breaking of C-C as well as an OO bond, then added the 1,3-dipolar carbonyl.
Individual evidence
- ↑ Milton Orchin, Roger S. Macomber, Allan R. Pinhas, R. Marshall Wilson: The Vocabulary and Concepts of Organic Chemistry. 2nd edition, John Wiley & Sons, Hoboken 2005, ISBN 0-471-68028-1 , pp. 583-584.
- ↑ Benoit Braida, Christof Walter, Bernd Engels, Philippe C. Hiberty: A Clear Correlation between the Diradical Character of 1,3-Dipoles and Their Reactivity toward Ethylene or Acetylene . In: Journal of the American Chemical Society . tape 132 , no. 22 , June 9, 2010, ISSN 0002-7863 , p. 7631-7637 , doi : 10.1021 / ja100512d .
- ^ Ivan Ernest: Binding, structure and reaction mechanisms in organic chemistry , Springer-Verlag, 1972, ISBN 3-211-81060-9 , pp. 349-350.