Benzimidazolium‐ and Benzimidazolilydene‐Capped Cyclodextrins: New Perspectives in Anion Encapsulation and Gold‐Catalyzed Cycloisomerization of 1, 6‐Enynes. Issue 68 (8th November 2018)

• Record Type: Journal Article
• Authors: Kaya, Zeyneb; Andna, Lucile; Matt, Dominique; Bentouhami, Embarek; Djukic, Jean‐Pierre; Armspach, Dominique
• Is Part Of: Chemistry. Volume 24:Issue 68(2018)
• Page Start: 17921
• Page End: 17926
• Publication Date: 2018-11-08
• Subjects: anions -- catalysis -- cyclodextrin -- gold -- N-heterocyclic carbenes; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201804710
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A new way of introducing a N‐heterocyclic carbene cap onto cyclodextrins has been devised. The benzimidazolium intermediates were found to behave as receptors towards cavity matching anions. The corresponding C 1 ‐ and C 2 ‐symmetrical regioisomeric carbene gold(I) complexes have been tested in a benchmark asymmetric cycloisomerization of 1, 6‐enynes. Up to 50 % ee was achieved for the enantioselective cycloisomerization of N ‐allyl‐4‐methyl‐ N ‐(3‐phenylprop‐2‐yn‐1‐yl)benzenesulfonamide. Abstract : Permethylated cyclodextrins equipped with a benzimidazolium handle behave as receptors towards medium‐sized anions. They could be directly converted to NHC gold(I) complexes that act as precatalysts for the asymmetric cycloisomerization of 1, 6‐enynes.