Correlation Engine 2.0
Clear Search sequence regions


Symmetrical diarylalkynes were obtained from propiolic acid (or 2-butynedioic acid) and aryl halides in good yields. The optimized reaction conditions were 2.0 equiv of aryl halide, 1.0 equiv of propiolic acid, 5.0 mol % Pd(PPh(3))(2)Cl(2), 10.0 mol % 1,4-bis(diphenylphosphino)butane (dppb), 2.0 equiv of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and dimethyl sulfoxide (DMSO) as the solvent. The coupling reaction of 2-butynedioic acid with aryl halides required 110 °C. The coupling reaction showed tolerance for functional groups such as ester, ketone, and aldehyde and exhibited chemoselectivity. In the coupling reaction of propiolic acid with aryl bromide, the diarylated product was the major one at 80 °C, even though 1 equiv of aryl halides was employed. However, among the monoarylated products that were formed predominantly at 25 and 50 °C in the coupling reaction with aryl iodide, more Sonogashira coupling product was obtained than the decarboxylative coupling product. Unsymmetrical diarylalkynes were also synthesized via this method, in which all reagents, including propiolic acid, aryl iodide, and aryl bromides were added at the beginning of the reaction.

Citation

Kyungho Park, Goun Bae, Jeongju Moon, Jaehoon Choe, Kwang Ho Song, Sunwoo Lee. Synthesis of symmetrical and unsymmetrical diarylalkynes from propiolic acid using palladium-catalyzed decarboxylative coupling. The Journal of organic chemistry. 2010 Sep 17;75(18):6244-51

Expand section icon Mesh Tags

Expand section icon Substances


PMID: 20795634

View Full Text