Rate and equilibrium constants for the addition of N-heterocyclic carbenes into benzaldehydes: a remarkable 2-substituent effect

Christopher John Collett; Richard S Massey; James Edward Taylor; Oliver R Maguire; AnnMarie C O'Donoghue; Andrewv D. Smith

doi:10.1002/anie.201501840

Rate and equilibrium constants for the addition of N-heterocyclic carbenes into benzaldehydes: a remarkable 2-substituent effect

Christopher John Collett, Richard S Massey, James Edward Taylor, Oliver R Maguire, AnnMarie C O'Donoghue^*, Andrewv D. Smith^*

^*Corresponding author for this work

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

Abstract

Rate and equilibrium constants for the reaction between N-aryl triazolium NHC precatalysts and substituted benzaldehyde derivatives to form 3-(hydroxybenzyl)azolium adducts under both catalytic and stoichiometric conditions have been measured. Kinetic analysis and reaction profile fitting of both the forward and reverse reactions, plus onwards reaction to the Breslow intermediate, demonstrate the remarkable effect of the benzaldehyde 2-substituent in these reactions and provide insight into the chemoselectivity of cross-benzoin reactions.

Original language	English
Pages (from-to)	6887-6892
Journal	Angewandte Chemie International Edition
Volume	54
Issue number	23
Early online date	23 Apr 2015
DOIs	https://doi.org/10.1002/anie.201501840
Publication status	Published - 27 May 2015

Keywords

N-heterocyclic carbenes
Organocatalysis
Mechanistic studies
Kinetics
2-substituent effect

Access to Document

10.1002/anie.201501840Licence: CC BY

Collett_et_al-2015-Angewandte_Chemie_International_Edition
Copyright 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Final published version, 735 KBLicence: CC BY

Cite this

@article{524efb9895344159b4cbf95978420840,

title = "Rate and equilibrium constants for the addition of N-heterocyclic carbenes into benzaldehydes: a remarkable 2-substituent effect",

abstract = "Rate and equilibrium constants for the reaction between N-aryl triazolium NHC precatalysts and substituted benzaldehyde derivatives to form 3-(hydroxybenzyl)azolium adducts under both catalytic and stoichiometric conditions have been measured. Kinetic analysis and reaction profile fitting of both the forward and reverse reactions, plus onwards reaction to the Breslow intermediate, demonstrate the remarkable effect of the benzaldehyde 2-substituent in these reactions and provide insight into the chemoselectivity of cross-benzoin reactions.",

keywords = "N-heterocyclic carbenes, Organocatalysis, Mechanistic studies, Kinetics, 2-substituent effect",

author = "Collett, \{Christopher John\} and Massey, \{Richard S\} and Taylor, \{James Edward\} and Maguire, \{Oliver R\} and O'Donoghue, \{AnnMarie C\} and Smith, \{Andrewv D.\}",

note = "We thank the Royal Society for a University Research Fellowship (ADS), the EPSRC (CJC and RM) grant number EP/G013268/1 and the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) ERC grant agreement no 279850 (JET). We also thank the EPSRC UK National Mass Spectrometry Facility at Swansea University. ",

year = "2015",

month = may,

day = "27",

doi = "10.1002/anie.201501840",

language = "English",

volume = "54",

pages = "6887--6892",

journal = "Angewandte Chemie International Edition",

issn = "1433-7851",

publisher = "John Wiley \& Sons, Ltd",

number = "23",

}

TY - JOUR

T1 - Rate and equilibrium constants for the addition of N-heterocyclic carbenes into benzaldehydes

T2 - a remarkable 2-substituent effect

AU - Collett, Christopher John

AU - Massey, Richard S

AU - Taylor, James Edward

AU - Maguire, Oliver R

AU - O'Donoghue, AnnMarie C

AU - Smith, Andrewv D.

N1 - We thank the Royal Society for a University Research Fellowship (ADS), the EPSRC (CJC and RM) grant number EP/G013268/1 and the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) ERC grant agreement no 279850 (JET). We also thank the EPSRC UK National Mass Spectrometry Facility at Swansea University.

PY - 2015/5/27

Y1 - 2015/5/27

N2 - Rate and equilibrium constants for the reaction between N-aryl triazolium NHC precatalysts and substituted benzaldehyde derivatives to form 3-(hydroxybenzyl)azolium adducts under both catalytic and stoichiometric conditions have been measured. Kinetic analysis and reaction profile fitting of both the forward and reverse reactions, plus onwards reaction to the Breslow intermediate, demonstrate the remarkable effect of the benzaldehyde 2-substituent in these reactions and provide insight into the chemoselectivity of cross-benzoin reactions.

AB - Rate and equilibrium constants for the reaction between N-aryl triazolium NHC precatalysts and substituted benzaldehyde derivatives to form 3-(hydroxybenzyl)azolium adducts under both catalytic and stoichiometric conditions have been measured. Kinetic analysis and reaction profile fitting of both the forward and reverse reactions, plus onwards reaction to the Breslow intermediate, demonstrate the remarkable effect of the benzaldehyde 2-substituent in these reactions and provide insight into the chemoselectivity of cross-benzoin reactions.

KW - N-heterocyclic carbenes

KW - Organocatalysis

KW - Mechanistic studies

KW - Kinetics

KW - 2-substituent effect

UR - https://www.scopus.com/pages/publications/84930221830

U2 - 10.1002/anie.201501840

DO - 10.1002/anie.201501840

M3 - Article

SN - 1433-7851

VL - 54

SP - 6887

EP - 6892

JO - Angewandte Chemie International Edition

JF - Angewandte Chemie International Edition

IS - 23

ER -

Rate and equilibrium constants for the addition of N-heterocyclic carbenes into benzaldehydes: a remarkable 2-substituent effect

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

ERC Starting Grant EnolCat: Emulating nature: Reaction diversity and understanding through asymmetric catalysis

RS Uni Research Fellowship Renewal 2010: University Research Fellowship - Cabranes ans Lewis Bases as Organocatalysts Synthetic Applications

Mechanistic Studies of Nucleophilic: EPSRC Collab - Hetrocyclic Carbenes

Andrew Smith

Cite this

Rate and equilibrium constants for the addition of N-heterocyclic carbenes into benzaldehydes: a remarkable 2-substituent effect

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Projects

ERC Starting Grant EnolCat: Emulating nature: Reaction diversity and understanding through asymmetric catalysis

RS Uni Research Fellowship Renewal 2010: University Research Fellowship - Cabranes ans Lewis Bases as Organocatalysts Synthetic Applications

Mechanistic Studies of Nucleophilic: EPSRC Collab - Hetrocyclic Carbenes

Profiles

Andrew Smith

Cite this