Catalytic activities in the direct C5 arylation of novel palladium

Abstract

New palladium N-heterocyclic carbene (NHC) complexes (1a-e) were synthesized in very good yields by the reaction of 1-phenyl-3-alkylbenzimidazolium salts with Pd(OAc)(2) in dimethyl sulfoxide. These synthesized complexes were fully characterized using elemental analyses, FT-IR, H-1 NMR, C-13 NMR and LC-MS (for 1a, 1c and 1e) spectroscopy data. Also, the molecular structure of the bis[1-phenyl-3-(2methyl-1,4-benzodioxane)benzimidazol-2-ylidene] dibromopalladium(II) complex (1d) was structurally characterized by single crystal X-ray diffraction study. The new Pd-II complexes (1a-e) were tested as catalysts in the direct C5 arylation of 2-n-butylfuran, 2-n-butylthiophene and 2-n-propylthiazole with various aryl bromides at 130 degrees C for 1 h. Also, some experiments were carried out by using aryl chlorides in order to be used for comparison. The results are reported herein. These complexes exhibited quite high catalytic activities under the given conditions. (C) 2014 Elsevier B.V. All rights reserved.

C1 [Akkoc, Senem] Erciyes Univ, Dept Chem, Fac Sci, TR-38039 Kayseri, Turkey.

[Gok, Yetkin] Inonu Univ, Dept Chem, Fac Sci & Arts, TR-44280 Malatya, Turkey.

[Akkurt, Mehmet] Erciyes Univ, Dept Phys, Fac Sci, TR-38039 Kayseri, Turkey.

[Tahir, Muhammad Nawaz] Sargodha Univ, Dept Phys, Fac Sci, Sargodha, Pakistan.