Organic base effects in NHC promoted O- to C-carboxyl transfer; chemoselectivity profiles, mechanistic studies and domino catalysis

Craig D. Campbell; Christopher J. Collett; Jennifer E. Thomson; Alexandra M. Z. Slawin; Andrew D. Smith

doi:10.1039/c1ob05160a

Organic base effects in NHC promoted O- to C-carboxyl transfer; chemoselectivity profiles, mechanistic studies and domino catalysis

Craig D. Campbell, Christopher J. Collett, Jennifer E. Thomson, Alexandra M. Z. Slawin, Andrew D. Smith

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

Abstract

The O- to C-carboxyl transfer of oxazolyl carbonates promoted by triazolinylidenes, generated in situ with NEt3, shows a markedly different rate and chemoselectivity profile to the same reaction promoted by triazolinylidenes generated using KHMDS. The mechanism of these pathways has been probed through extensive crossover studies to understand this process. The use of NEt3 as a base allows domino multi-step reaction sequences to be developed, although chiral NHCs only generate modest levels of asymmetric induction (<15% ee) in these domino reaction processes.

Original language	English
Pages (from-to)	4205-4218
Number of pages	14
Journal	Organic & Biomolecular Chemistry
Volume	9
Issue number	11
DOIs	https://doi.org/10.1039/c1ob05160a
Publication status	Published - 2011

Keywords

N-HETEROCYCLIC CARBENE
HIGHLY ENANTIOSELECTIVE SYNTHESIS
INTERMOLECULAR STETTER REACTION
STEGLICH REARRANGEMENT REACTION
ALPHA,BETA-UNSATURATED ALDEHYDES
NUCLEOPHILIC CATALYSTS
ASYMMETRIC-SYNTHESIS
GAMMA-BUTYROLACTONES
KINETIC RESOLUTION
STABLE CARBENES

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title = "Organic base effects in NHC promoted O- to C-carboxyl transfer; chemoselectivity profiles, mechanistic studies and domino catalysis",

abstract = "The O- to C-carboxyl transfer of oxazolyl carbonates promoted by triazolinylidenes, generated in situ with NEt3, shows a markedly different rate and chemoselectivity profile to the same reaction promoted by triazolinylidenes generated using KHMDS. The mechanism of these pathways has been probed through extensive crossover studies to understand this process. The use of NEt3 as a base allows domino multi-step reaction sequences to be developed, although chiral NHCs only generate modest levels of asymmetric induction (<15% ee) in these domino reaction processes.",

keywords = "N-HETEROCYCLIC CARBENE, HIGHLY ENANTIOSELECTIVE SYNTHESIS, INTERMOLECULAR STETTER REACTION, STEGLICH REARRANGEMENT REACTION, ALPHA,BETA-UNSATURATED ALDEHYDES, NUCLEOPHILIC CATALYSTS, ASYMMETRIC-SYNTHESIS, GAMMA-BUTYROLACTONES, KINETIC RESOLUTION, STABLE CARBENES",

author = "Campbell, {Craig D.} and Collett, {Christopher J.} and Thomson, {Jennifer E.} and Slawin, {Alexandra M. Z.} and Smith, {Andrew D.}",

year = "2011",

doi = "10.1039/c1ob05160a",

language = "English",

volume = "9",

pages = "4205--4218",

journal = "Organic & Biomolecular Chemistry",

issn = "1477-0520",

publisher = "Royal Society of Chemistry",

number = "11",

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TY - JOUR

T1 - Organic base effects in NHC promoted O- to C-carboxyl transfer; chemoselectivity profiles, mechanistic studies and domino catalysis

AU - Campbell, Craig D.

AU - Collett, Christopher J.

AU - Thomson, Jennifer E.

AU - Slawin, Alexandra M. Z.

AU - Smith, Andrew D.

PY - 2011

Y1 - 2011

N2 - The O- to C-carboxyl transfer of oxazolyl carbonates promoted by triazolinylidenes, generated in situ with NEt3, shows a markedly different rate and chemoselectivity profile to the same reaction promoted by triazolinylidenes generated using KHMDS. The mechanism of these pathways has been probed through extensive crossover studies to understand this process. The use of NEt3 as a base allows domino multi-step reaction sequences to be developed, although chiral NHCs only generate modest levels of asymmetric induction (<15% ee) in these domino reaction processes.

AB - The O- to C-carboxyl transfer of oxazolyl carbonates promoted by triazolinylidenes, generated in situ with NEt3, shows a markedly different rate and chemoselectivity profile to the same reaction promoted by triazolinylidenes generated using KHMDS. The mechanism of these pathways has been probed through extensive crossover studies to understand this process. The use of NEt3 as a base allows domino multi-step reaction sequences to be developed, although chiral NHCs only generate modest levels of asymmetric induction (<15% ee) in these domino reaction processes.

KW - N-HETEROCYCLIC CARBENE

KW - HIGHLY ENANTIOSELECTIVE SYNTHESIS

KW - INTERMOLECULAR STETTER REACTION

KW - STEGLICH REARRANGEMENT REACTION

KW - ALPHA,BETA-UNSATURATED ALDEHYDES

KW - NUCLEOPHILIC CATALYSTS

KW - ASYMMETRIC-SYNTHESIS

KW - GAMMA-BUTYROLACTONES

KW - KINETIC RESOLUTION

KW - STABLE CARBENES

U2 - 10.1039/c1ob05160a

DO - 10.1039/c1ob05160a

M3 - Article

SN - 1477-0520

VL - 9

SP - 4205

EP - 4218

JO - Organic & Biomolecular Chemistry

JF - Organic & Biomolecular Chemistry

IS - 11

ER -

Organic base effects in NHC promoted O- to C-carboxyl transfer; chemoselectivity profiles, mechanistic studies and domino catalysis

Abstract

Keywords

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