It is an intramolecular rearrangement reaction in which the 1,2-migration of silyl group from carbon to oxygen under basic conditions.It involves the formation of a pentacoordinate siliconintermediate.Discovered by Adrian Gibbs Brook in 1958.

1. BROOK
REARRANGEMENT
PREPARED BY
ANUSREE V
1ST SEMESTER MPHARM
PHARMACEUTICAL CHEMISTRY
AL SHIFA COLLEGE OF PHARMACY

2. INTRODUCTION
Discovered by Canadian Chemist
Adrian Gibbs Brook in 1958.
Also known as [1,2]-Brook
rearrangement or [1,2]-Silyl
migration.
Intramolecular rearrangement.
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3. DEFINITION
 The 1,2- migration of a silyl group from carbon
to oxygen under basic conditions is known as
Brook rearrangement.
 Rearrangement of α-silyloxyanion to α-
silylcarbanions involving a pentacoordinate
siliconintermediate. 3

4. 4
Alpha-silyl
oxyanion
Pentacoordinate
siliconintermediate
Alpha-silyl
carbanion
Silyl ether or
Oxysilane

5. REACTION
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6. METHODS FOR GENERATION OF
α -SILYLALKOXIDES
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7. MECHANISM
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8. CHARACTERISTICS
 The rate of reaction depends on the amount of
added base, but this was not consumed and was
used in substoichiometric amounts. So the
reaction follows Pseudofirst order kinetics.
 A silyl shift from oxygen to carbon, the reverse
process is called retro-Brook rearrangement. 8

9. •[1,2]-silyl migration is a equilibrium process.
•Aza- or Thia- variants of the rearrangement
involving silyl shifts from carbon to nitrogen or
sulphur respectively, have also been observed.
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10. SYNTHETIC APPLICATIONS
 K. Takeda and co-workers synthesized the tricyclic core
of the cyanthins using a Brook rearragement mediated-
reaction.
APPLICATION 1:
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11. APPLICATION 2:
 K. Takeda developed a new synthetic strategy for the
stereoselective construction of 8 membered
carbocycles utilizing a Brook rearrangement.
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12. APPLICATION 3:
 E.J. Corey synthesized (+)- Onocerin from farnesyl
acetate- derived acyl silane via four-component
coupling and tetracyclization steps.
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13. REFERENCE
 JiebJack Li:Name Reactions Third Edition;Springer
Science & Bussiness Media, 2006:Page no:83-84
 Laszlo Kurti,Barbara Czako:Strategic Applications of
Named Reactions in Organic Synthesis;Elsevier,29-
Apr-2005;page no:64-65
 Christian M. Rojas:Molecular Rearrangements in
Organic Synthesis:Wiley,March-2015,Page no:207-241
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14. 14
A. Hassner, I.Namboothiri;Organic Syntheses Based
on Named Reactions, Third Edition;Elsevier;Page no:62
Michiko Sasaki, Kei Takeda:Brook rearrangement:
Wiley Online library:2-Oct-2015:Chapter 6
TutorVista.com

15. THANK YOU...
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