Intermolecular Desymmetrizing Gold‐Catalyzed Yne–Yne Reaction of Push–Pull Diarylalkynes

• Published in: Chemistry : a European journal Vol. 24; no. 15; pp. 3725 - 3728
• Main Authors: Weingand, Vanessa, Wurm, Thomas, Vethacke, Vanessa, Dietl, Martin C., Ehjeij, Daniel, Rudolph, Matthias, Rominger, Frank, Xie, Jin, Hashmi, A. Stephen K.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 12.03.2018; Wiley Subscription Services, Inc
• Subjects: alkyne dimerization; Alkynes; Aromatic compounds; Atom economy; Cations; Chemistry; Chemistry, Multidisciplinary; Gold; gold catalysis; naphthalenes; Physical Sciences; push–pull systems; Science & Technology; vinyl cations; naphthalenes; push-pull systems; alkyne dimerization; COMPLEXES; TERMINAL ALKYNES; gold catalysis; vinyl cations; VINYLIDENES; CYCLIZATIONS; CYCLOISOMERIZATION; 1,6-DIYNES; DERIVATIVES; SELECTIVITY; ACCESS; DIYNE REACTION
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201800360

Push–pull diaryl alkynes are dimerized in the presence of a cationic gold catalyst. The polarized structure of the applied starting materials enables the generation of a highly reactive vinyl cation intermediate in an intermolecular reaction. Trapping of the vinyl cation by a nucleophilic attack of the electron‐poor aryl unit then leads to the selective formation of highly substituted naphthalenes in a single step and in complete atom economy. Tolan wedding: The intermolecular and selective gold‐catalyzed dimerization of polarized tolan derivatives gives highly substituted naphthalenes via reactive vinyl cation intermediates. This methodology is superior to existing unselective strategies catalyzed by other transition metals and offers an entry to naphthalenes with a controlled substitution pattern of electron‐rich and electron‐poor aryl groups (see scheme).