PAPER	Synthesis 2006: 2653-2658   DOI: 10.1055/s-2006-942466
© Georg Thieme Verlag Stuttgart · New York
Functionalized Ionic Liquid as an Efficient and Recyclable Reaction Medium for Phosphine-Free Palladium-Catalyzed Heck Reaction
Li Zhoua, Lei Wang*a,b
a Department of Chemistry, Huaibei Coal Teachers College, Huaibei, Anhui 235000, P. R. of China b State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, P. R. of China Fax: +86(561)3090518; e-Mail: leiwang@hbcnc.edu.cn;
Received 13 March 2006

Abstract

A functionalized ionic liquid, 1-(2-hydroxyethyl)-3-methyl­imidazolium tetrafluoroborate ([HEmim][BF₄]), was found to be as an efficient and recyclable reaction medium for palladium-catalyzed Heck reaction. The olefination of iodoarenes and bromo­arenes with olefins generated the corresponding products in good to excellent yields under phosphine-free reaction conditions. The reaction involved the use of [HEmim][BF₄] as the solvent, potassium phosphate as the base, and palladium acetate as the catalyst. In addition, palladium and ionic liquid could be recovered and recycled for six consecutive trials without significant loss of its reactivity.

Key words

Heck reaction - palladium acetate - phosphine-free - functionalized ionic liquid - 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([HEmim][BF₄])