The Preparation of Substituted Pyrazoles from beta,beta-Dibromo-enones by a Tandem Condensation/Suzuki-Miyaura Cross-Coupling Process

Sandra Beltran-Rodil; Michael G. Edwards; David. S. Pugh; Mark Reid; Richard J. K. Taylor

doi:10.1055/s-0029-1218521

The Preparation of Substituted Pyrazoles from beta,beta-Dibromo-enones by a Tandem Condensation/Suzuki-Miyaura Cross-Coupling Process

Sandra Beltran-Rodil, Michael G. Edwards, David. S. Pugh, Mark Reid, Richard J. K. Taylor

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

Two consecutive tandem processes are described for the regioselective, two-step synthesis of 1,3,5-trisubstituted pyrazoles from alpha-hydroxyketones. The first, a tandem MnO2-mediated oxidation/Ramirez olefination reaction, provides a facile route to beta,beta-dibromo-enones. These valuable 1,3-dicarbonyl synthons can then be converted into 1,3,5-trisubstituted pyrazoles via a second tandem hydrazine condensation/Suzuki-Miyaura cross-coupling reaction. Using these procedures, a range of aryl and alkyl alpha-hydroxyketones have been transformed regioselectively into 1,3,5-trisubstituted pyrazoles.

Original language	English
Article number	D27509ST
Pages (from-to)	602-606
Number of pages	5
Journal	Synlett
Issue number	4
DOIs	https://doi.org/10.1055/s-0029-1218521
Publication status	Published - Mar 2010

Keywords

tandem oxidation process
TOP
beta,beta-dibromo-enones
1,3,5-trisubstituted pyrazoles
Suzuki-Miyaura
ONE-POT CONVERSION
OXIDATION PROCESSES
MANGANESE-DIOXIDE
KETONES
1,1-DIBROMO-1-ALKENES
DERIVATIVES
ALKYNES

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10.1055/s-0029-1218521

Cite this

@article{1e2041e98eb64ad9b5e9b3da25436778,

title = "The Preparation of Substituted Pyrazoles from beta,beta-Dibromo-enones by a Tandem Condensation/Suzuki-Miyaura Cross-Coupling Process",

abstract = "Two consecutive tandem processes are described for the regioselective, two-step synthesis of 1,3,5-trisubstituted pyrazoles from alpha-hydroxyketones. The first, a tandem MnO2-mediated oxidation/Ramirez olefination reaction, provides a facile route to beta,beta-dibromo-enones. These valuable 1,3-dicarbonyl synthons can then be converted into 1,3,5-trisubstituted pyrazoles via a second tandem hydrazine condensation/Suzuki-Miyaura cross-coupling reaction. Using these procedures, a range of aryl and alkyl alpha-hydroxyketones have been transformed regioselectively into 1,3,5-trisubstituted pyrazoles.",

keywords = "tandem oxidation process, TOP, beta,beta-dibromo-enones, 1,3,5-trisubstituted pyrazoles, Suzuki-Miyaura, ONE-POT CONVERSION, OXIDATION PROCESSES, MANGANESE-DIOXIDE, KETONES, 1,1-DIBROMO-1-ALKENES, DERIVATIVES, ALKYNES",

author = "Sandra Beltran-Rodil and Edwards, {Michael G.} and Pugh, {David. S.} and Mark Reid and Taylor, {Richard J. K.}",

year = "2010",

month = mar,

doi = "10.1055/s-0029-1218521",

language = "English",

pages = "602--606",

journal = "Synlett",

issn = "1437-2096",

publisher = "Georg Thieme Verlag",

number = "4",

}

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T1 - The Preparation of Substituted Pyrazoles from beta,beta-Dibromo-enones by a Tandem Condensation/Suzuki-Miyaura Cross-Coupling Process

AU - Beltran-Rodil, Sandra

AU - Edwards, Michael G.

AU - Pugh, David. S.

AU - Reid, Mark

AU - Taylor, Richard J. K.

PY - 2010/3

Y1 - 2010/3

N2 - Two consecutive tandem processes are described for the regioselective, two-step synthesis of 1,3,5-trisubstituted pyrazoles from alpha-hydroxyketones. The first, a tandem MnO2-mediated oxidation/Ramirez olefination reaction, provides a facile route to beta,beta-dibromo-enones. These valuable 1,3-dicarbonyl synthons can then be converted into 1,3,5-trisubstituted pyrazoles via a second tandem hydrazine condensation/Suzuki-Miyaura cross-coupling reaction. Using these procedures, a range of aryl and alkyl alpha-hydroxyketones have been transformed regioselectively into 1,3,5-trisubstituted pyrazoles.

AB - Two consecutive tandem processes are described for the regioselective, two-step synthesis of 1,3,5-trisubstituted pyrazoles from alpha-hydroxyketones. The first, a tandem MnO2-mediated oxidation/Ramirez olefination reaction, provides a facile route to beta,beta-dibromo-enones. These valuable 1,3-dicarbonyl synthons can then be converted into 1,3,5-trisubstituted pyrazoles via a second tandem hydrazine condensation/Suzuki-Miyaura cross-coupling reaction. Using these procedures, a range of aryl and alkyl alpha-hydroxyketones have been transformed regioselectively into 1,3,5-trisubstituted pyrazoles.

KW - tandem oxidation process

KW - TOP

KW - beta,beta-dibromo-enones

KW - 1,3,5-trisubstituted pyrazoles

KW - Suzuki-Miyaura

KW - ONE-POT CONVERSION

KW - OXIDATION PROCESSES

KW - MANGANESE-DIOXIDE

KW - KETONES

KW - 1,1-DIBROMO-1-ALKENES

KW - DERIVATIVES

KW - ALKYNES

U2 - 10.1055/s-0029-1218521

DO - 10.1055/s-0029-1218521

M3 - Article

SN - 1437-2096

SP - 602

EP - 606

JO - Synlett

JF - Synlett

IS - 4

M1 - D27509ST

ER -