NaIO4-mediated asymmetric bromohydroxylation of α,β-unsaturated carboxamides with high diastereoselectivity: a short route to (-)-cytoxazone and droxidopa

Shyla George; Srinivasarao V. Narina; Arumugam Sudalai

doi:10.1016/j.tetlet.2006.12.109

NaIO₄-mediated asymmetric bromohydroxylation of α,β-unsaturated carboxamides with high diastereoselectivity: a short route to (-)-cytoxazone and droxidopa

Shyla George, Srinivasarao V. Narina, Arumugam Sudalai

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

18 Scopus citations

Abstract

The NaIO₄-mediated asymmetric bromohydroxylation of α,β-unsaturated carboxamides was achieved using lithium bromide as the bromine source under acidic conditions at rt to afford the corresponding chiral α-bromo-β-hydroxy carboxamides. Excellent yields (77-90%) and diastereoselectivities (up to 10:1) along with exclusive control over regio- as well as anti-selectivity are the main features with a good scope of substrates. The method has successfully been applied in the enantioselective syntheses of two biologically important molecules, viz (-)-cytoxazone and l-threo-DOPS (droxidopa).

Original language	English (US)
Pages (from-to)	1375-1378
Number of pages	4
Journal	Tetrahedron Letters
Volume	48
Issue number	8
DOIs	https://doi.org/10.1016/j.tetlet.2006.12.109
State	Published - Feb 19 2007
Externally published	Yes

Bibliographical note

Funding Information:
S.G. and N.V.S. thank CSIR, New Delhi, for the award of research fellowships. The authors are thankful to Dr. B. D. Kulkarni, Deputy Director, for his support and encouragement.

Keywords

Asymmetric bromohydroxylation
Carboxamide
Cytoxazone
Droxidopa
NaIO

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title = "NaIO4-mediated asymmetric bromohydroxylation of α,β-unsaturated carboxamides with high diastereoselectivity: a short route to (-)-cytoxazone and droxidopa",

abstract = "The NaIO4-mediated asymmetric bromohydroxylation of α,β-unsaturated carboxamides was achieved using lithium bromide as the bromine source under acidic conditions at rt to afford the corresponding chiral α-bromo-β-hydroxy carboxamides. Excellent yields (77-90%) and diastereoselectivities (up to 10:1) along with exclusive control over regio- as well as anti-selectivity are the main features with a good scope of substrates. The method has successfully been applied in the enantioselective syntheses of two biologically important molecules, viz (-)-cytoxazone and l-threo-DOPS (droxidopa).",

keywords = "Asymmetric bromohydroxylation, Carboxamide, Cytoxazone, Droxidopa, NaIO",

author = "Shyla George and Narina, {Srinivasarao V.} and Arumugam Sudalai",

note = "Funding Information: S.G. and N.V.S. thank CSIR, New Delhi, for the award of research fellowships. The authors are thankful to Dr. B. D. Kulkarni, Deputy Director, for his support and encouragement.",

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T2 - a short route to (-)-cytoxazone and droxidopa

AU - George, Shyla

AU - Narina, Srinivasarao V.

AU - Sudalai, Arumugam

N1 - Funding Information: S.G. and N.V.S. thank CSIR, New Delhi, for the award of research fellowships. The authors are thankful to Dr. B. D. Kulkarni, Deputy Director, for his support and encouragement.

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AB - The NaIO4-mediated asymmetric bromohydroxylation of α,β-unsaturated carboxamides was achieved using lithium bromide as the bromine source under acidic conditions at rt to afford the corresponding chiral α-bromo-β-hydroxy carboxamides. Excellent yields (77-90%) and diastereoselectivities (up to 10:1) along with exclusive control over regio- as well as anti-selectivity are the main features with a good scope of substrates. The method has successfully been applied in the enantioselective syntheses of two biologically important molecules, viz (-)-cytoxazone and l-threo-DOPS (droxidopa).

KW - Asymmetric bromohydroxylation

KW - Carboxamide

KW - Cytoxazone

KW - Droxidopa

KW - NaIO

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