Lee JH, Raja GC, Yu S, Lee J, Song KH, Lee S. Palladium-Catalyzed Decarboxylative Coupling of Alkynyl Carboxylic Acids with Aryl Tosylates.
ACS OMEGA 2017;
2:6259-6269. [PMID:
31457871 PMCID:
PMC6644868 DOI:
10.1021/acsomega.7b01165]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 09/18/2017] [Indexed: 06/10/2023]
Abstract
Decarboxylative coupling reactions of alkynyl carboxylic acids with aryl tosylates were developed in the presence of a palladium catalyst. Among the commercially available phosphine ligands, only 1-dicyclohexylphosphino-2-(di-tert-butylphosphino-ethyl)ferrocene (CyPF-tBu) showed good reactivity. The reaction took place smoothly and gave the decarboxylative coupled products in moderate to good yields. This demonstrates the excellent functional group tolerance toward alkyl, alkoxy, fluoro, thiophenyl, ester, and ketone groups. In addition, alkyl-substituted propiolic acids, such as octynoic and hexynoic acids, were coupled with phenyl tosylate to provide the desired products. We found that the electronic properties of the substituents on the phenyl ring in arylpropiolic acids are an important factor. The order of reactivity was found to be aryl iodide > aryl bromide > aryl tosylate > aryl chloride. However, aryl chloride-bearing electron-withdrawing groups showed higher reactivity than those bearing aryl tosylates.
Collapse