Environmentally Benign Cross-Couplings

  • Author: Li Grundl
  • Published: 27 April 2017
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
  • Source / Publisher: Organic Letters/ACS Publishing
thumbnail image: Environmentally Benign Cross-Couplings

Cross-coupling reactions are widely used to form C–C and C–N bonds. While palladium catalysts are still dominantly used, copper catalysts are attracting more attention because they are more abundant, less expensive, and less toxic. Pincer complexes consist of tridentate ligands bind to a metal. They are rarely used in copper chemistry.

Karl Kirchner, Vienna University of Technology, Vienna, Austria, and colleagues have developed an air-stable, thermally robust, and well-defined copper PNP pincer complex (pictured). They treated CuBr(Me2S) with the pincer ligand PNPMe-iPr, which is based on the 2,6-diaminopyridine scaffold, in dichloromethane at room temperature. The structure of the complex has been determined by single-crystal X-ray diffraction.

The researchers found that this neutral complex was an active catalyst for cross-couplings of (hetero)aryl and aliphatic halides with Grignard reagents, terminal alkynes, and aryl amines, although CuBr(Me2S) itself was poorly active or inactive in those reactions. All reactions were performed in THF with 1 mol % of the catalyst at 50 °C for 16 h. Good to excellent yields were observed in most cases.


Article Views: 1767

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. more

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

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