Gold promoted arylative cyclization of alkynoic acids with arenediazonium salts
Alkynoic acids derived from salicylic acid and analogues undergo arylative cyclization with arenediazonium salts promoted by gold in the absence of external ligands. The reaction is thermally induced and proceeds even in the absence of light. A difference in regioselectivity has been found compared with that observed in the cycloisomerization process of the same type of compounds.
Carrillo-Arcos, Ulises A.,Porcel, Susana
p. 1837 - 1842
(2018/03/23)
Palladium-catalyzed cyclization of alkynoic acids to form vinyl dioxanones bearing a quaternary allylic carbon
A palladium-catalyzed intramolecular reaction of carboxylic acids and alkynes in a novel cyclization manner was developed. This unique cyclization efficiently provided a wide range of complex ring systems-vinyl dioxanones bearing a quaternary allylic carbon. Mechanistic studies suggest an allenyl carboxylate as an intermediate.
Ogiwara, Yohei,Sato, Kazuya,Sakai, Norio
p. 5296 - 5299
(2017/11/06)
Silver(I) and gold(I)-promoted synthesis of alkylidene lactones and 2H-chromenes from salicylic and anthranilic acid derivatives
Ag(I) and Au(I) efficiently catalyze the cycloisomerization of terminal alkynoic acids into methylene seven-membered ring lactones. Depending on the metal, divergent reaction pathways were found for non terminal alkynoic acids. While Ag(I) led to lactones, Au(I) led to 2H-chromenes coming from the hydroarylation of the alkyne.