No abstract

Novel five-membered ( κ 2 −C, N ) -palladacyclic complexes were prepared from the reaction of the corresponding acetate-bridged palladacycle dimer with N-heterocyclic carbene (NHC) ligands in high yields. Palladacyclic complexes (3) were fully characterized by elemental analysis and 1 H and 13 C NMR spectroscopy. Palladacyclic complexes were tested as catalyst for the C-C bond forming reaction. These complexes were found to be efficient catalysts for the Suzuki-Miyaura reaction of aryl bromides.

New derivatives of sp2–sp3 and sp3–sp3 diboranes were prepared via a carbodiimide-induced rearrangement process.

A series of monomeric palladacycle complexes bearing n‐butyl‐substituted N‐heterocyclic carbenes, namely [Pd(NHC)X(dmba)] (dmba: dimethylbenzylamine and [Pd(NHC)X(ppy)]; NHC: 1‐n‐butyl‐3‐substituted benzylimidazol‐2‐ylidene; ppy: 2‐phenylpyridine), were prepared either by transmetallation from the corresponding silver carbene complexes or by the reaction of the corresponding acetate‐bridged palladacycle dimer with N‐heterocyclic carbene ligands in high yields. The palladium(II) complexes were characterized using elemental analyses, APCI‐MS, 1H NMR and 13C NMR spectroscopies. These complexes are efficient in the Suzuki–Miyaura coupling reaction between phenylboronic acid and aryl bromides.

A new series of sterically hindered ligands containing (1R,2S,4R)-(+)-menthoxymethyl group attached to benzimidazole-based Nheterocyclic carbene (NHC), palladium-bis-NHC complexes and (κ 2 -C,N)-palladacyclic NHC complexes have been synthesized and characterized using appropriate spectroscopic techniques. Catalytic performance of the palladium complexes has been investigated for allylic alkylation, Suzuki and Heck carbon-carbon coupling reactions. These complexes smoothly catalyse the carboncarbon bond formation reactions.