Enantioselective NHC-Catalysed Formal [4+2] Cycloaddition of Alkylarylketenes with beta, gamma-Unsaturated alpha-Ketophosphonates

Stuart Minto Leckie; Charlene Fallan; James Edward Taylor; T. Bruce Brown; David Pryde; Tomas Lebl; Alexandra Martha Zoya Slawin; Andrew David Smith

doi:10.1055/s-0033-1338851

Enantioselective NHC-Catalysed Formal [4+2] Cycloaddition of Alkylarylketenes with beta, gamma-Unsaturated alpha-Ketophosphonates

Stuart Minto Leckie, Charlene Fallan, James Edward Taylor, T. Bruce Brown, David Pryde, Tomas Lebl, Alexandra Martha Zoya Slawin, Andrew David Smith

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

14 Citations (Scopus)

Abstract

NHC-mediated enantioselective formal [4+2] cycloadditions of alkylarylketenes with gamma-substituted-beta,gamma-unsaturated alpha-ketophosphonates is described. A substrate-dependent switch in diastereoselectivity was observed, with gamma-aryl alpha-ketophosphonates providing preferentially the syn-dihydropyranone-phosphonates and gamma-methyl alpha-ketophosphonates favouring the anti-dihydropyranone-phosphonate. In addition, ketene generation in situ retained high levels of stereoselectivity and led to improved product yields when compared with the corresponding two-step procedure.

Original language	English
Pages (from-to)	1243-1249
Number of pages	7
Journal	Synlett
Volume	24
Issue number	10
DOIs	https://doi.org/10.1055/s-0033-1338851
Publication status	Published - Jun 2013

Keywords

N-heterocyclic carbenes
cycloaddition
asymmetric catalysis
asymmetric synthesis
lactones
N-HETEROCYCLIC CARBENE
C-CARBOXYL TRANSFER
ALPHA,BETA-UNSATURATED ALDEHYDES
MICHAEL ADDITION
ASYMMETRIC ORGANOCATALYSIS
NUCLEOPHILIC CARBENES
DISUBSTITUTED KETENES
CHIRAL ALCOHOLS
ESTERS
ACYL

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@article{986319edba684777a20fcd09181b170d,

title = "Enantioselective NHC-Catalysed Formal [4+2] Cycloaddition of Alkylarylketenes with beta, gamma-Unsaturated alpha-Ketophosphonates",

abstract = "NHC-mediated enantioselective formal [4+2] cycloadditions of alkylarylketenes with gamma-substituted-beta,gamma-unsaturated alpha-ketophosphonates is described. A substrate-dependent switch in diastereoselectivity was observed, with gamma-aryl alpha-ketophosphonates providing preferentially the syn-dihydropyranone-phosphonates and gamma-methyl alpha-ketophosphonates favouring the anti-dihydropyranone-phosphonate. In addition, ketene generation in situ retained high levels of stereoselectivity and led to improved product yields when compared with the corresponding two-step procedure.",

keywords = "N-heterocyclic carbenes, cycloaddition, asymmetric catalysis, asymmetric synthesis, lactones, N-HETEROCYCLIC CARBENE, C-CARBOXYL TRANSFER, ALPHA,BETA-UNSATURATED ALDEHYDES, MICHAEL ADDITION, ASYMMETRIC ORGANOCATALYSIS, NUCLEOPHILIC CARBENES, DISUBSTITUTED KETENES, CHIRAL ALCOHOLS, ESTERS, ACYL",

author = "Leckie, {Stuart Minto} and Charlene Fallan and Taylor, {James Edward} and Brown, {T. Bruce} and David Pryde and Tomas Lebl and Slawin, {Alexandra Martha Zoya} and Smith, {Andrew David}",

note = "We thank the Royal Society for a University Research Fellowships (A.D.S.), the EPSRC and Pfizer (CASE funding for S.M.L.) and the EU (C.F. and J.E.T.) for funding, as well as the European Research Council under the European Union{\textquoteright}s Seventh Framework Programme (FP7/2007-2013) ERC grant agreement No. 279850.",

year = "2013",

month = jun,

doi = "10.1055/s-0033-1338851",

language = "English",

volume = "24",

pages = "1243--1249",

journal = "Synlett",

issn = "0936-5214",

publisher = "Georg Thieme Verlag",

number = "10",

}

TY - JOUR

T1 - Enantioselective NHC-Catalysed Formal [4+2] Cycloaddition of Alkylarylketenes with beta, gamma-Unsaturated alpha-Ketophosphonates

AU - Leckie, Stuart Minto

AU - Fallan, Charlene

AU - Taylor, James Edward

AU - Brown, T. Bruce

AU - Pryde, David

AU - Lebl, Tomas

AU - Slawin, Alexandra Martha Zoya

AU - Smith, Andrew David

N1 - We thank the Royal Society for a University Research Fellowships (A.D.S.), the EPSRC and Pfizer (CASE funding for S.M.L.) and the EU (C.F. and J.E.T.) for funding, as well as the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC grant agreement No. 279850.

PY - 2013/6

Y1 - 2013/6

N2 - NHC-mediated enantioselective formal [4+2] cycloadditions of alkylarylketenes with gamma-substituted-beta,gamma-unsaturated alpha-ketophosphonates is described. A substrate-dependent switch in diastereoselectivity was observed, with gamma-aryl alpha-ketophosphonates providing preferentially the syn-dihydropyranone-phosphonates and gamma-methyl alpha-ketophosphonates favouring the anti-dihydropyranone-phosphonate. In addition, ketene generation in situ retained high levels of stereoselectivity and led to improved product yields when compared with the corresponding two-step procedure.

AB - NHC-mediated enantioselective formal [4+2] cycloadditions of alkylarylketenes with gamma-substituted-beta,gamma-unsaturated alpha-ketophosphonates is described. A substrate-dependent switch in diastereoselectivity was observed, with gamma-aryl alpha-ketophosphonates providing preferentially the syn-dihydropyranone-phosphonates and gamma-methyl alpha-ketophosphonates favouring the anti-dihydropyranone-phosphonate. In addition, ketene generation in situ retained high levels of stereoselectivity and led to improved product yields when compared with the corresponding two-step procedure.

KW - N-heterocyclic carbenes

KW - cycloaddition

KW - asymmetric catalysis

KW - asymmetric synthesis

KW - lactones

KW - N-HETEROCYCLIC CARBENE

KW - C-CARBOXYL TRANSFER

KW - ALPHA,BETA-UNSATURATED ALDEHYDES

KW - MICHAEL ADDITION

KW - ASYMMETRIC ORGANOCATALYSIS

KW - NUCLEOPHILIC CARBENES

KW - DISUBSTITUTED KETENES

KW - CHIRAL ALCOHOLS

KW - ESTERS

KW - ACYL

U2 - 10.1055/s-0033-1338851

DO - 10.1055/s-0033-1338851

M3 - Article

SN - 0936-5214

VL - 24

SP - 1243

EP - 1249

JO - Synlett

JF - Synlett

IS - 10

ER -

Enantioselective NHC-Catalysed Formal [4+2] Cycloaddition of Alkylarylketenes with beta, gamma-Unsaturated alpha-Ketophosphonates

Abstract

Keywords

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