Concave 1,10-Phenanthrolines as Ligands for Cyclopropanations – Towards a Deeper Understanding of the Stereoselectivity
✍ Scribed by Friederike Eggers; Ulrich Lüning
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 477 KB
- Volume
- 2009
- Category
- Article
- ISSN
- 1434-193X
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✦ Synopsis
Abstract
Four new mono‐ and bimacrocyclic 1,10‐phenanthrolines – 3b and 4a–c – containing aryl bridgeheads have been synthesised. The etherification of the aryl bridgeheads was accomplished by Williamson or Mitsunobu reactions. A key step in the synthesis of the macrocyclic phenanthrolines 3 and 4 is the Suzuki coupling of 2,9‐diiodo‐1,10‐phenanthroline (12) with the appropriately substituted boronic acids 17 and 20. Ring‐closing metathesis and hydrogenation completed the synthesis. The resulting macrocyclic 1,10‐phenanthrolines 3b and 4a–c were tested as ligands in a copper(I)‐catalysed stereoselective cyclopropanation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)