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

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.

Citation

Collett , C J , Massey , R S , Taylor , J E , Maguire , O R , O'Donoghue , A C & Smith , A D 2015 , ' Rate and equilibrium constants for the addition of N-heterocyclic carbenes into benzaldehydes : a remarkable 2-substituent effect ' , Angewandte Chemie International Edition , vol. 54 , no. 23 , pp. 6887-6892 . https://doi.org/10.1002/anie.201501840

Publication

Angewandte Chemie International Edition

Status

Peer reviewed

DOI

https://doi.org/10.1002/anie.201501840

ISSN

1433-7851

Type

Journal article

Rights

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.

Description

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.

Collections

University of St Andrews Research

URI

http://hdl.handle.net/10023/7082