Pd(II)-Catalyzed Olefination of Electron-Deficient Arenes Using 2,6-Dialkylpyridine Ligands

Abstract

Pd(II)-catalyzed meta-olefination of highly electron deficient arenes is achieved through the use of a rationally designed mutually repulsive ligand. The combination of directed and non-directed C-H functionalization of arenes provides a versatile route for the synthesis of highly sought-after 1,2,4-trisubstituted arenes.Since the discovery of the Pd-catalyzed olefination of benzene by Fujiwara, substantial progress has been made to improve the efficiency and practicality of this reaction. 1 To date, reactivity is still limited to electron rich arenes, 1-4 except for a single example using chlorobenzene, a moderately electron deficient arene. 1c Furthermore, olefination of monosubstituted arenes gives an approximately even mixture of ortho-, meta-and para-olefinated products, 1c limiting possible synthetic applications. The ortho-olefination of benzoic acids and anilides via directed C-H activation reported by Miura and de Vries, respectively, represents an important approach to control the regioselectivity of this reaction. 5,6 Herein, we report the first example of a meta-selective olefination process of highly electron deficient arenes. This reaction is promoted by a novel mutually repulsive 2,6-dialkylpyridine ligand, yu200@scripps.edu. Supporting Information Available: Experimental procedure and characterization of all new compounds (PDF). This material is available free of charge via the Internet at

Super-reactive catalyst for bond cleavage

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