Synthesis of Fulvene Vinyl Ethers by Gold Catalysis. Issue 23 (6th April 2020)

• Record Type: Journal Article
• Authors: Ahrens, Alexander; Schwarz, Julia; Lustosa, Danilo M.; Pourkaveh, Raheleh; Hoffmann, Marvin; Rominger, Frank; Rudolph, Matthias; Dreuw, Andreas; Hashmi, A. Stephen K.
• Is Part Of: Chemistry. Volume 26:Issue 23(2020)
• Page Start: 5280
• Page End: 5287
• Publication Date: 2020-04-06
• Subjects: aryl cations -- fulvene ethers -- gold catalysis -- vinyl cations -- vinyl ethers; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202000338
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Gold‐catalyzed cyclization of 1, 5‐diynes with ketones as reagents and solvent provides diversely substituted vinyl ethers under mild conditions. The regioselectivity of such gold‐catalyzed cyclizations is usually controlled by the scaffold of the diyne. Herein, we report the first solvent‐controlled switching of regioselectivity from a 6‐ endo‐dig‐ to 5‐endo‐dig ‐cyclization in these transformations, providing fulvene derivatives. With respect to the functional‐group tolerance, aryl fluorides, chlorides, bromides, and ethers are tolerated. Furthermore, the mechanism and selectivity are put to scrutiny by experimental studies and a thermodynamic analysis of the product. Additionally, 6‐(vinyloxy)fulvenes are a hitherto unknown class of compounds. Their reactivity is briefly evaluated, to give insights into their potential applications. Abstract : Regioselective switch : Gold‐catalyzed cyclization of 1, 5‐diynes with ketones as reagents and solvent provides diversely substituted vinyl ethers under mild conditions. The regioselectivity of such gold‐catalyzed cyclizations is usually controlled by the scaffold of the diyne. In this work, the first solvent‐controlled switching of regioselectivity from a 6‐ endo‐dig‐ to 5‐endo‐dig ‐cyclization in these transformations, providing fulvene derivatives is reported (see scheme).