NHC-mediated enantioselective formal [4 + 2] cycloadditions of alkylarylketenes and β,γ-unsaturated α-ketocarboxylic esters and amides

Stuart M. Leckie; T. Bruce Brown; David Pryde; Tomas Lebl; Alexandra M. Z. Slawin; Andrew D. Smith

doi:10.1039/c3ob40424b

NHC-mediated enantioselective formal [4 + 2] cycloadditions of alkylarylketenes and β,γ-unsaturated α-ketocarboxylic esters and amides

Stuart M. Leckie, T. Bruce Brown, David Pryde, Tomas Lebl, Alexandra M. Z. Slawin, Andrew D. Smith^*

^*Corresponding author for this work

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

Abstract

Chiral N-heterocyclic carbenes (NHCs) promote the asymmetric formal [4 + 2] cycloaddition of alkylarylketenes with β,γ-unsaturated α-ketocarboxylic esters and amides. Divergent diastereoselectivity is observed in this process, with γ-aryl-β,γ-unsaturated α-ketocarboxylic esters and amides giving preferentially syn-dihydropyranones (up to 68:32 dr syn:anti, up to 98% ee), while γ-alkyl-derivatives generate anti-dihydropyranones (up to 18:82 dr syn:anti, up to 75% ee). © The Royal Society of Chemistry 2013.

Original language	English
Pages (from-to)	3230-3246
Number of pages	17
Journal	Organic & Biomolecular Chemistry
Volume	11
Issue number	19
Early online date	15 Apr 2013
DOIs	https://doi.org/10.1039/c3ob40424b
Publication status	Published - 21 May 2013

Keywords

DIELS-ALDER REACTIONS
N-HETEROCYCLIC CARBENES
C-CARBOXYL TRANSFER
SILYL KETENE ACETALS
ALPHA,BETA-UNSATURATED ALDEHYDES
CATALYZED CYCLOADDITION
DISUBSTITUTED KETENES
OXAZOLYL CARBONATES
CHIRAL ALCOHOLS
O-CARBOXYL

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@article{894339f473604324800e70d17d32225a,

title = "NHC-mediated enantioselective formal [4 + 2] cycloadditions of alkylarylketenes and β,γ-unsaturated α-ketocarboxylic esters and amides",

abstract = "Chiral N-heterocyclic carbenes (NHCs) promote the asymmetric formal [4 + 2] cycloaddition of alkylarylketenes with β,γ-unsaturated α-ketocarboxylic esters and amides. Divergent diastereoselectivity is observed in this process, with γ-aryl-β,γ-unsaturated α-ketocarboxylic esters and amides giving preferentially syn-dihydropyranones (up to 68:32 dr syn:anti, up to 98% ee), while γ-alkyl-derivatives generate anti-dihydropyranones (up to 18:82 dr syn:anti, up to 75% ee). {\textcopyright} The Royal Society of Chemistry 2013.",

keywords = "DIELS-ALDER REACTIONS, N-HETEROCYCLIC CARBENES, C-CARBOXYL TRANSFER, SILYL KETENE ACETALS, ALPHA,BETA-UNSATURATED ALDEHYDES, CATALYZED CYCLOADDITION, DISUBSTITUTED KETENES, OXAZOLYL CARBONATES, CHIRAL ALCOHOLS, O-CARBOXYL",

author = "Leckie, {Stuart M.} and Brown, {T. Bruce} and David Pryde and Tomas Lebl and Slawin, {Alexandra M. Z.} and Smith, {Andrew D.}",

year = "2013",

month = may,

day = "21",

doi = "10.1039/c3ob40424b",

language = "English",

volume = "11",

pages = "3230--3246",

journal = "Organic & Biomolecular Chemistry",

issn = "1477-0520",

publisher = "Royal Society of Chemistry",

number = "19",

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TY - JOUR

T1 - NHC-mediated enantioselective formal [4 + 2] cycloadditions of alkylarylketenes and β,γ-unsaturated α-ketocarboxylic esters and amides

AU - Leckie, Stuart M.

AU - Brown, T. Bruce

AU - Pryde, David

AU - Lebl, Tomas

AU - Slawin, Alexandra M. Z.

AU - Smith, Andrew D.

PY - 2013/5/21

Y1 - 2013/5/21

N2 - Chiral N-heterocyclic carbenes (NHCs) promote the asymmetric formal [4 + 2] cycloaddition of alkylarylketenes with β,γ-unsaturated α-ketocarboxylic esters and amides. Divergent diastereoselectivity is observed in this process, with γ-aryl-β,γ-unsaturated α-ketocarboxylic esters and amides giving preferentially syn-dihydropyranones (up to 68:32 dr syn:anti, up to 98% ee), while γ-alkyl-derivatives generate anti-dihydropyranones (up to 18:82 dr syn:anti, up to 75% ee). © The Royal Society of Chemistry 2013.

AB - Chiral N-heterocyclic carbenes (NHCs) promote the asymmetric formal [4 + 2] cycloaddition of alkylarylketenes with β,γ-unsaturated α-ketocarboxylic esters and amides. Divergent diastereoselectivity is observed in this process, with γ-aryl-β,γ-unsaturated α-ketocarboxylic esters and amides giving preferentially syn-dihydropyranones (up to 68:32 dr syn:anti, up to 98% ee), while γ-alkyl-derivatives generate anti-dihydropyranones (up to 18:82 dr syn:anti, up to 75% ee). © The Royal Society of Chemistry 2013.

KW - DIELS-ALDER REACTIONS

KW - N-HETEROCYCLIC CARBENES

KW - C-CARBOXYL TRANSFER

KW - SILYL KETENE ACETALS

KW - ALPHA,BETA-UNSATURATED ALDEHYDES

KW - CATALYZED CYCLOADDITION

KW - DISUBSTITUTED KETENES

KW - OXAZOLYL CARBONATES

KW - CHIRAL ALCOHOLS

KW - O-CARBOXYL

UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84876945971&partnerID=8YFLogxK

U2 - 10.1039/c3ob40424b

DO - 10.1039/c3ob40424b

M3 - Article

SN - 1477-0520

VL - 11

SP - 3230

EP - 3246

JO - Organic & Biomolecular Chemistry

JF - Organic & Biomolecular Chemistry

IS - 19

ER -

NHC-mediated enantioselective formal [4 + 2] cycloadditions of alkylarylketenes and β,γ-unsaturated α-ketocarboxylic esters and amides

Abstract

Keywords

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