Enantioselective NHC-catalysed redox [4+2]-hetero-Diels-Alder reactions using α-aroyloxyaldehydes and unsaturated ketoesters

James E. Taylor; Alyn T. Davies; James J. Douglas; Gwydion Churchill; Andrew D. Smith

doi:10.1016/j.tetasy.2017.01.002

Enantioselective NHC-catalysed redox [4+2]-hetero-Diels-Alder reactions using α-aroyloxyaldehydes and unsaturated ketoesters

James E. Taylor, Alyn T. Davies, James J. Douglas, Gwydion Churchill, Andrew D. Smith

Department of Chemistry

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

15 Citations (SciVal)

Abstract

N-Heterocyclic carbene (NHC)-catalysed redox [4+2]-hetero-Diels-Alder reactions of α-aroyloxyaldehydes with either β,γ-unsaturated α-ketoesters or α,β-unsaturated γ-ketoesters generates substituted syn-dihydropyranones in good yield with excellent enantioselectivity (up to >99:1 er). The product diastereoselectivity is markedly dependent upon the nature of the unsaturated enone substituent. The presence of either electron-neutral or electron-rich aryl substituents gives excellent diastereoselectivity (up to >99:5 dr), while electron-deficient aryl substituents give reduced diastereoselectivity. In these cases, the syn-dihydropyranone products are more susceptible to base-promoted epimerisation at the C(4)-position under the reaction conditions, accounting for the lower diastereoselectivity obtained.

Original language	English
Pages (from-to)	355-366
Number of pages	12
Journal	Tetrahedron Asymmetry
Volume	28
Issue number	2
Early online date	19 Jan 2017
DOIs	https://doi.org/10.1016/j.tetasy.2017.01.002
Publication status	Published - 15 Feb 2017

Funding

We thank the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) ERC Grant Agreement No. 279850 (J.E.T. and A.T.D.) as well as the EPSRC, UK and AstraZeneca plc, UK (Case award to J.J.D.) for financial support. A.D.S. thanks the Royal Society, London, UK, for a Wolfson Merit Award. We also thank the EPSRC UK National Mass Spectrometry Facility at Swansea University.

ASJC Scopus subject areas

Catalysis
Physical and Theoretical Chemistry
Organic Chemistry
Inorganic Chemistry

Access to Document

10.1016/j.tetasy.2017.01.002

Cite this

@article{2c9524c0e44d4915a7940ea2c802803c,

title = "Enantioselective NHC-catalysed redox [4+2]-hetero-Diels-Alder reactions using α-aroyloxyaldehydes and unsaturated ketoesters",

abstract = "N-Heterocyclic carbene (NHC)-catalysed redox [4+2]-hetero-Diels-Alder reactions of α-aroyloxyaldehydes with either β,γ-unsaturated α-ketoesters or α,β-unsaturated γ-ketoesters generates substituted syn-dihydropyranones in good yield with excellent enantioselectivity (up to >99:1 er). The product diastereoselectivity is markedly dependent upon the nature of the unsaturated enone substituent. The presence of either electron-neutral or electron-rich aryl substituents gives excellent diastereoselectivity (up to >99:5 dr), while electron-deficient aryl substituents give reduced diastereoselectivity. In these cases, the syn-dihydropyranone products are more susceptible to base-promoted epimerisation at the C(4)-position under the reaction conditions, accounting for the lower diastereoselectivity obtained.",

author = "Taylor, {James E.} and Davies, {Alyn T.} and Douglas, {James J.} and Gwydion Churchill and Smith, {Andrew D.}",

year = "2017",

month = feb,

day = "15",

doi = "10.1016/j.tetasy.2017.01.002",

language = "English",

volume = "28",

pages = "355--366",

journal = "Tetrahedron Asymmetry",

issn = "0957-4166",

publisher = "Elsevier",

number = "2",

}

TY - JOUR

T1 - Enantioselective NHC-catalysed redox [4+2]-hetero-Diels-Alder reactions using α-aroyloxyaldehydes and unsaturated ketoesters

AU - Taylor, James E.

AU - Davies, Alyn T.

AU - Douglas, James J.

AU - Churchill, Gwydion

AU - Smith, Andrew D.

PY - 2017/2/15

Y1 - 2017/2/15

N2 - N-Heterocyclic carbene (NHC)-catalysed redox [4+2]-hetero-Diels-Alder reactions of α-aroyloxyaldehydes with either β,γ-unsaturated α-ketoesters or α,β-unsaturated γ-ketoesters generates substituted syn-dihydropyranones in good yield with excellent enantioselectivity (up to >99:1 er). The product diastereoselectivity is markedly dependent upon the nature of the unsaturated enone substituent. The presence of either electron-neutral or electron-rich aryl substituents gives excellent diastereoselectivity (up to >99:5 dr), while electron-deficient aryl substituents give reduced diastereoselectivity. In these cases, the syn-dihydropyranone products are more susceptible to base-promoted epimerisation at the C(4)-position under the reaction conditions, accounting for the lower diastereoselectivity obtained.

AB - N-Heterocyclic carbene (NHC)-catalysed redox [4+2]-hetero-Diels-Alder reactions of α-aroyloxyaldehydes with either β,γ-unsaturated α-ketoesters or α,β-unsaturated γ-ketoesters generates substituted syn-dihydropyranones in good yield with excellent enantioselectivity (up to >99:1 er). The product diastereoselectivity is markedly dependent upon the nature of the unsaturated enone substituent. The presence of either electron-neutral or electron-rich aryl substituents gives excellent diastereoselectivity (up to >99:5 dr), while electron-deficient aryl substituents give reduced diastereoselectivity. In these cases, the syn-dihydropyranone products are more susceptible to base-promoted epimerisation at the C(4)-position under the reaction conditions, accounting for the lower diastereoselectivity obtained.

UR - http://www.scopus.com/inward/record.url?scp=85009811538&partnerID=8YFLogxK

U2 - 10.1016/j.tetasy.2017.01.002

DO - 10.1016/j.tetasy.2017.01.002

M3 - Article

AN - SCOPUS:85009811538

SN - 0957-4166

VL - 28

SP - 355

EP - 366

JO - Tetrahedron Asymmetry

JF - Tetrahedron Asymmetry

IS - 2

ER -

Enantioselective NHC-catalysed redox [4+2]-hetero-Diels-Alder reactions using α-aroyloxyaldehydes and unsaturated ketoesters

Abstract

Funding

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this