Journal article

Publication year: 2014

Pages: 6394-6398

Journal: European Journal of Organic Chemistry

Volume number: 2014

Issue number: 29

DOI Link: https://doi.org/10.1002/ejoc.201402871

Publisher: Wiley

Abstract: 

The hydrogen‐bonding strength of a variety of commonly employed thiourea catalysts was quantified by using a trialkylphosphine oxide as a 31P NMR probe. Simple diarylthioureas and more complex bifunctional amine‐ and hydroxy‐substituted thiourea derivatives were examined. Their catalytic activity was determined in a Diels–Alder reaction, and the obtained pseudo‐first‐order rate constants were correlated with the 31P NMR chemical shifts. A linear correlation between both variables was observed throughout the functionalized thioureas. The 31P NMR probe correlation fared better in comparison to a pKa correlation. Accordingly, the quantification presented herein by using a 31P NMR probe offers an elegant way to estimate the catalytic activity of thiourea catalysts in hydrogen‐bond‐activated reactions such as the Diels–Alder reaction.

Harvard Citation style: Nödling, A., Jakab, G., Schreiner, P. and Hilt, G. (2014) 31P NMR Spectroscopically Quantified Hydrogen‐Bonding Strength of Thioureas and Their Catalytic Activity in Diels–Alder Reactions, European Journal of Organic Chemistry, 2014(29), pp. 6394-6398. https://doi.org/10.1002/ejoc.201402871

APA Citation style: Nödling, A., Jakab, G., Schreiner, P., & Hilt, G. (2014). 31P NMR Spectroscopically Quantified Hydrogen‐Bonding Strength of Thioureas and Their Catalytic Activity in Diels–Alder Reactions. European Journal of Organic Chemistry. 2014(29), 6394-6398. https://doi.org/10.1002/ejoc.201402871