Synthesis of Substituted Naphthalenes and Carbazoles by the Palladium-Catalyzed Annulation of Internal Alkynes

• Published in: Journal of organic chemistry Vol. 68; no. 19; pp. 7342 - 7349
• Main Authors: Huang, Qinhua, Larock, Richard C
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 19.09.2003; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Condensed benzenic and aromatic compounds; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; ISOQUINOLINES; ALPHA-PYRONES; LIGNANS; INHIBITORS; PYRIDINES; IMINOANNULATION; DERIVATIVES; INDOLES; CYCLIZATION; Catalytic reaction; Acetylenic compound; Regioselectivity; Nitrogen heterocycle; Palladium Complexes; Carbazole derivatives; Transition metal Complexes; Aldehyde; Naphthalene derivatives; Enynic compound; Annelation; Steric effect; Tertiary amine; Benzenic compound; Platinoid Complexes; Aromatic compound; Electronic effect; Indole derivatives; Chemical synthesis; Alkyne
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo034449x

An efficient synthesis of highly substituted naphthalenes has been developed by the palladium-catalyzed annulation of a variety of internal alkynes, in which two new carbon−carbon bonds are formed in a single step under relatively mild reaction conditions. This method has also been used to synthesize carbazoles, although a higher reaction temperature is necessary. The process involves arylpalladation of the alkyne, followed by intramolecular Heck olefination and double-bond isomerization. This method accommodates a variety of functional groups and affords the anticipated highly substituted naphthalenes and carbazoles in good to excellent yields.