Brook rearrangement

The Brook rearrangement is a name reaction from the field of organic chemistry and was first observed in 1958 by Adrian Gibbs Brook (1924-2013). The reaction involves intramolecular migration of a silyl group from a carbon atom to an oxygen atom .

Overview reaction

The Brook rearrangement is carried out in a basic , aqueous solution .

The silyl group drawn in blue is rearranged from the carbon atom to the oxygen atom. The radicals on the Sylilgruppe stand for alkyl groups and are identical. The radicals on the carbon atom can stand for alkyl groups or hydrogen and can be different. Primary and secondary amines , caustic soda or sodium hydride are used as bases .

Possible mechanism

The following mechanism of the Brook rearrangement is explained using trimethylsilylmethanol as an example. The methyl radicals of the silyl group are abbreviated as Me.

Mechanism using trimethylsilylmethanol as an example

The base attacks the hydrogen atom of the hydroxyl group of trimethylsilylmethanol ( 1 ) and deprotonates it. Thereafter, the free electron engages the alcoholate 2 , the trimethylsilyl group at, so that the stable Trimethysiliciumoxid connection 3 is formed. The methoxytrimethylsilane ( 4 ) is formed by subsequent work-up with water .

application

The reaction is mainly used in the preparation of dimeric amino acid derivatives .

literature

Bradford P. Mundy, Michael G. Ellerd, Frang G. Favaloro JR .: Name Reactions and Reagents in Organic Synthesis . Second Edition, John Wiley & Sons, New York 2005, ISBN 0-471-22854-0 , pp. 118-119.
Zerong Wang: Comprehensive Organic Name Reactions and Reagents . John Wiley & Sons, Ney Jersey 2009, ISBN 978-0-471-70450-8 , pp. 529-535.

Individual evidence

^ Zerong Wang: Comprehensive Organic Name Reactions and Reagents. John Wiley & Sons, New Jersey 2009, ISBN 978-0-471-70450-8 , p. 529.
↑ Bradford P. Mundy, Michael G. Ellerd, Frang G. Favaloro JR .: Name Reactions and Reagents in Organic Synthesis . Second Edition, John Wiley & Sons, New York 2005, p. 114.
^ Zerong Wang: Comprehensive Organic Name Reactions and Reagents . John Wiley & Sons, New Jersey 2009, p. 531.

[ZW1-1] Zerong Wang: Comprehensive Organic Name Reactions and Reagents. John Wiley & Sons, New Jersey 2009, ISBN 978-0-471-70450-8 , p. 529.

[PGF-2] Bradford P. Mundy, Michael G. Ellerd, Frang G. Favaloro JR .: Name Reactions and Reagents in Organic Synthesis . Second Edition, John Wiley & Sons, New York 2005, p. 114.

[ZW2-3] Zerong Wang: Comprehensive Organic Name Reactions and Reagents . John Wiley & Sons, New Jersey 2009, p. 531.