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Thermoregulated Copper‐Free Sonogashira Coupling in Water
Author(s) -
Liu Ning,
Liu Chun,
Xu Qiang,
Jin Zilin
Publication year - 2011
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201100367
Subject(s) - sonogashira coupling , chemistry , aryl , halide , catalysis , copper , palladium , ligand (biochemistry) , reactivity (psychology) , combinatorial chemistry , coupling reaction , aryl halide , medicinal chemistry , organic chemistry , alkyl , medicine , biochemistry , receptor , alternative medicine , pathology
The Sonogashira cross‐coupling reaction between aryl halides and terminal alkynes was carried out smoothly in water over a thermoregulated ligand–palladium catalyst under copper‐free conditions, resulting in good to excellent yields. The Sonogashira reaction was sensitive to the electronic nature of the substituents on the aryl halides. Aryl halides with an electron‐withdrawing group showed higher reactivity than those with an electron‐donating group. Particularly, this protocol could be applied to the synthesis of liquid crystals involving trans ‐cyclohexyltolans. The products could be separated from the reaction system easily by decanting, and the catalyst was recovered in water and used directly for the next run.