Fritsch-Buttenberg-Wiechell rearrangement

The Fritsch-Buttenberg-Wiechell rearrangement is a name reaction of organic chemistry, which is named after its discoverers Paul Ernst Moritz Fritsch (1859–1913), Wilhelm Paul Buttenberg and Heinrich G. Wiechell . It is a rearrangement reaction in which a 1,1-disubstituted vinyl halide is converted to an alkyne . The substituents can be aryl or alkyl substituents, but also hydrogen atoms. It is carried out with a strong base (e.g. an alcoholate or butyllithium ).

Reaction mechanism

The proposed reaction mechanism of the Fritsch-Buttenberg-Wiechell rearrangement is shown here using an alcoholate as an example.

The reaction starts with the vinyl halide 1 . A strong base, here an alcoholate, deprotonates the alkene, forming the corresponding alcohol and the alkenyl anion 2 . The halide is eliminated, with the intermediate carbene 3 being formed. After migration of one of the two substituents, the alkyne 4 is formed with the formation of a triple bond .

Practical use

The Fritsch-Buttenberg-Wiechell rearrangement can be used, among other things, for the synthesis of terminal alkynes. For example, alkynylated steroid hormones which are of pharmaceutical interest can be represented.

literature

Benjamin Darses, Anne Milet, Christian Philouze, Andrew E. Greene, Jean-François Poisson: Ynol Ethers from Dichloroenol Ethers: Mechanistic Elucidation Through ³⁵ Cl Labeling . In: Organic Letters . tape 10 , no. 20 , October 16, 2008, p. 4445-4447 , doi : 10.1021 / ol801704u .

Individual evidence

↑ H. Rezaei, S. Yamanoi, F. Chemla, JF Normant: Fritsch - Buttenberg - Wiechell rearrangement in the Aliphatic Series . In: Organic Letters . tape 2 , no. 4 , February 1, 2000, p. 419-421 , doi : 10.1021 / ol991117z .
↑ Paul Fritsch: About the preparation of diphenylacetaldehyde and a new synthesis of tolane derivatives . In: Justus Liebig's Annals of Chemistry . tape 279 , no. 3 , January 1, 1894, p. 319-323 , doi : 10.1002 / jlac.18942790310 .
^ WP Buttenberg: Condensation of dichloroacetal with phenol and toluene . In: Justus Liebig's Annals of Chemistry . tape 279 , no. 3 , January 1, 1894, p. 324-337 , doi : 10.1002 / jlac.18942790311 .
^ H. Wiechell: Condensation of dichloroacetal with anisole and phenetole . In: Justus Liebig's Annals of Chemistry . tape 279 , no. 3 , January 1, 1894, p. 337-344 , doi : 10.1002 / jlac.18942790312 .
^ G. Köbrich: Eliminations from Olefins . In: Angewandte Chemie International Edition in English . tape 4 , no. 1 , January 1, 1965, p. 49-68 , doi : 10.1002 / anie.196500491 .
↑ Bradford P. Mundy, Michael G. Ellerd, Frank G. Favaloro, Jr .: Name Reactions and Reagents in Organic Synthesis . John Wiley, Hoboken (NJ) 2005, ISBN 0-471-22854-0 , pp. 262-263 .
↑ Eckhard Ottow, Ralph Rohde, Wolfgang Schwede, Rudolf Wiechert: Synthesis of 11β- (alkynyl) substituted 19-norsteroids . In: Tetrahedron Letters . 34, 1993, pp. 5253-5256, doi: 10.1016 / S0040-4039 (00) 73966-9 .

[rezaei2000-1] H. Rezaei, S. Yamanoi, F. Chemla, JF Normant: Fritsch - Buttenberg - Wiechell rearrangement in the Aliphatic Series . In: Organic Letters . tape 2 , no. 4 , February 1, 2000, p. 419-421 , doi : 10.1021 / ol991117z .

[fritsch1894-2] Paul Fritsch: About the preparation of diphenylacetaldehyde and a new synthesis of tolane derivatives . In: Justus Liebig's Annals of Chemistry . tape 279 , no. 3 , January 1, 1894, p. 319-323 , doi : 10.1002 / jlac.18942790310 .

[buttenberg1894-3] WP Buttenberg: Condensation of dichloroacetal with phenol and toluene . In: Justus Liebig's Annals of Chemistry . tape 279 , no. 3 , January 1, 1894, p. 324-337 , doi : 10.1002 / jlac.18942790311 .

[weichell1894-4] H. Wiechell: Condensation of dichloroacetal with anisole and phenetole . In: Justus Liebig's Annals of Chemistry . tape 279 , no. 3 , January 1, 1894, p. 337-344 , doi : 10.1002 / jlac.18942790312 .

[köbrich1965-5] G. Köbrich: Eliminations from Olefins . In: Angewandte Chemie International Edition in English . tape 4 , no. 1 , January 1, 1965, p. 49-68 , doi : 10.1002 / anie.196500491 .

[:Mundy-6] Bradford P. Mundy, Michael G. Ellerd, Frank G. Favaloro, Jr .: Name Reactions and Reagents in Organic Synthesis . John Wiley, Hoboken (NJ) 2005, ISBN 0-471-22854-0 , pp. 262-263 .

[7] Eckhard Ottow, Ralph Rohde, Wolfgang Schwede, Rudolf Wiechert: Synthesis of 11β- (alkynyl) substituted 19-norsteroids . In: Tetrahedron Letters . 34, 1993, pp. 5253-5256, doi: 10.1016 / S0040-4039 (00) 73966-9 .