Dual Catalysis for the Functionalization of Alcohols

  • Author: European Journal of Organic Chemistry
  • Published Date: 07 August 2019
  • Source / Publisher: European Journal of Organic Chemistry//Wiley-VCH
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
thumbnail image: Dual Catalysis for the Functionalization of Alcohols

Related Societies

The direct functionalization of alcohols is a useful method for the formation of new carbon–carbon bonds. The starting materials are readily available and water is formed as the only by-product. Catalytic reactions of this type are particularly interesting. Brønsted acids, for example, can act as catalysts in the dehydrative homocoupling of benzylic alcohols and  related couplings with nucleophiles.

Marlene Böldl and Ivana Fleischer, University of Tübingen, Germany, have found that a catalyst combination of toluenesulfonic acid as a Brønsted acid with the Lewis base triphenylphosphine leads to improved yields and shorter reaction times in the homocoupling of alcohols (pictured).

A variety of olefins were synthesized from benzylic alcohols under relatively mild conditions, i.e., in 1,2‐dichloroethane (DCE) at 60 °C within 18 h in air. Additionally, the method can be used for the dehydrative hydroarylation of benzylic alcohols with electron‐rich arenes, using only the Brønsted acid under otherwise identical reaction conditions.

To understand the role of the Lewis base, the team performed a series of mechanistic investigations, including the synthesis of plausible reaction intermediates as well as reaction progress and NMR studies. The results indicate that the phosphine stabilizes cationic reaction intermediates and prevents oligomerization side reactions.


Article Views: 1357

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission and consult our permission guidance prior to making your request

Follow on Facebook Follow on Twitter Follow on YouTube Follow on LinkedIn Follow on Instagram RSS Sign up for newsletters

Magazine of Chemistry Europe (16 European Chemical Societies) published by Wiley-VCH