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Indexed by:期刊论文

Date of Publication:2011-08-01

Journal:EUROPEAN JOURNAL OF ORGANIC CHEMISTRY

Included Journals:SCIE

Issue:23

Page Number:4422-4428

ISSN No.:1434-193X

Key Words:Cross-coupling; Palladium; Green chemistry; Biphasic catalysis; Ligand effects

Abstract: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.