Iodine‐Catalyzed Claisen‐Rearrangements of Allyl Aryl Ethers and Subsequent Iodocyclizations. Issue 5 (18th January 2023)

• Record Type: Journal Article
• Authors: Arndt, Thiemo; Raina, Abhinav; Breugst, Martin
• Is Part Of: Chemistry, an Asian journal. Volume 18:Issue 5(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-18
• Subjects: halogen bonding -- catalysis -- rearrangements -- DFT calculations -- reaction mechanism; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.202201279
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: Iodine can be considered as the simplest halogen‐bond donor. Previous investigations have revealed its remarkable catalytic effect in various reactions. The catalytic activity of iodine can often even compete with that of traditional Lewis acids. So far, iodine was typically used to activate carbonyl derivatives like Michael acceptors. We now demonstrate that iodine can also be used to activate allyl aryl ethers in Claisen rearrangements. The formed ortho ‐allylic phenols rapidly undergo iodocyclizations to afford dihydrobenzofurans, which are important building blocks for medicinal applications. A comparison with different catalysts further highlights the potential of iodine catalysis for this reaction. Computational and mechanistic investigations provide deeper insights into the underlying non‐covalent interactions and their role for the catalysis. Abstract : Claisen Rearrangements with a Twist . Molecular iodine catalyzes the Claisen rearrangement of allyl aryl ethers and substantially reduces the required reaction temperature for these processes. The resulting allyl phenols rapidly undergo iodocyclizations to afford dihydrobenzofurans, which are important building blocks for medicinal applications. DFT calculations and mechanistic studies provide further insights into this transformation.