2H-Indazoles are synthesized using copper-catalyzed, one-pot, three-component reactions of 2-bromobenzaldehydes, primary amines, and sodium azide. A copper catalyst plays the key role in the formation of C-N and N-N bonds. This method has a broad substrate scope with a high tolerance for a variety of functional groups.
Alkynyl carboxylic acids reacted with aryl iodides under a CO atmosphere in the presence of a palladium catalyst to produce α,β-alkynyl aryl ketones in good yields. The maximum turnover number was 16 800. The desired carbonylative coupling was formed from phenyl propiolic acid without any formation of a noncarbonylative coupling product in the absence of CuI. However, the reaction with alkyl-substituted alkynyl carboxylic acids required CuI as a cocatalyst for high yield.
Diarylalkynones were synthesized from one-pot Pd-catalyzed carbonylative and noncarbonylative coupling reactions of propiolic acid with aryl iodides under a carbon monoxide atmosphere. Aryl iodide (2.0 equiv), propiolic acid (1.0 equiv), Pd(PPh3)2Cl2 (5 mol %), CuCl (10 mol %), Et3N (6.0 equiv), and CO (8 atm) were reacted under optimized conditions in CH3CN at 80 °C for 1 h. This process afforded good yields and functional group tolerance.
Palladium-catalyzed carbonylation of aryl iodides and trimethylsilylacetonitrile to produce benzoylacetonitrile derivatives through a one-pot, three-component reaction is described. This preparation method provides good yields of the carbonylated products without any additional ligands. It has a broad substrate scope with a high tolerance for a variety of functional groups.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.