LAUSR

Mixed organo-halo palladium complexes of the type trans-(NHC)2Pd(R)Br were conveniently obtained from trans-(NHC)2PdBr2 type complexes by the ligand substitution reaction. In particular, the trans-[1-(1S)-menthyl-4-(R1)-1,2,4-triazol-5- ylidene]2Pd(R2)Br [R1 = Et, R2 = CH2Ph (3a1); R1 = Et, R2 = o-OMeC6H4 (3a2); R1 = R2 = CH2Ph (3b1); R1 = CH2Ph, R2 = o-OMeC6H4 (3b2)] complexes were obtained from the corresponding palladium(II) precursor complexes, 2(a−b), by the reaction with the respective Grignard reagents in good to excellent yields (74−93 %). Three of the four mixed organo-halo palladium complexes 3(a1−a2) and 3b1, have been structurally characterized by the single crystal X-ray diffraction technique that revealed the trans-disposition of the NHC ligands around the palladium center. The implication of this mixed organo-halo palladium complexes in the Suzuki-Miyaura cross-coupling reaction was established for all of the complexes, 3(a1−a2) and 3(b1−b2), that yielded the desired cross-coupled products upon treatment with various ArB(OH)2 [Ar = 1-naphthyl, 4-(1,1'-biphenyl), 9-phenanthrenyl, 4-FC6H4, and 2,6- Me2C6H3] in the presence of NaOH as a base, in CH3CN in 3 hours under reflux conditions.