PAVs. The availability of substrates, as well as simplicity of the method, are favorable features of this protocol. Another example of Hiyama coupling leading to the synthesis of ( E ) or ( Z )-oligo(arylene vinylenes) is the Pd-coupling reaction of 1,4-diiodobenzenes with 1,4-bis(silylethenyl)benzenes [ 32 ]. The Suzukicoupling, which is the most commonly used method for the formation of new carbon-carbon bonds, is used also in the formation of PAVs. Oligo(arylene vinylenes) or PAVs obtained according to the Suzukicoupling, due to the retention of the
One pot facile synthesis of ordered mesoporous alumina-supported zirconia with high thermal stability and large pore sizes by evaporation-induced method was systematically investigated. The strategy based on a sol-gel process associated with nonionic triblock copolymers PPO-PEO-PPO as templates in ethanolic solution. Small-angle XRD, TEM, and nitrogen adsorption and desorption results showed that these composites possessed an ordered 2D hexagonal mesostructure, resisted to high temperature up to 1000 °C, and had large surface areas and narrow pore-size distributions. Loaded with palladium, the mesoporous alumina-zirconia composite exhibited high catalytic activity in Suzuki coupling of 2-bromotoluene with phenylboronic acid.
Introduction Chromones (4 H -1-benzopyran-4-ones) are naturally occurring oxygen-containing heterocyclic compounds, which perform important biological functions in nature  and are a recognized pharmacophore of a large number of bioactive molecules of either natural or synthetic origin. Their derivatives are antibacterial, anticancer, antioxidant, estrogenic agents [2–4], and have been considered as privileged structures in drug development . The Suzukicoupling reaction is the palladium catalyzed C-C bond formation reaction of organoboran compounds with
A new palladium-bidentate complex [m-C6H4(CH2ImMe)2(PdCl2)] (III) was prepared in two steps. In the first step, [m-C6H4(CH2ImMeAgCl)2] (II) (Im = imidazole moiety) was obtained by reacting imidazolium salt [m-C6H4(CH2ImMe)2]Cl2 (I) (prepared by quaternisation of Nmethylimidazole with 1,3-bis(chloromethyl)benzene) and Ag2O in CH2Cl2. In the next step, treatment of (II) with Pd(CH3CN)2Cl2 afforded complex III which was evaluated for its catalytic activity for C-C bond-formation reactions by examining the coupling reaction of 3-iodoanisole with phenylacetylene in the Sonogashira reaction. In addition, 3-methoxybiphenyls were obtained with good to excellent yields by Suzuki coupling reactions of 3-iodoanisole with phenylboronic acids or phenylborates salts in the presence of this complex.
A palladium complex with an aminophosphine ligand has been prepared and investigated as a catalyst precursor in Suzuki coupling reactions in toluene. Nanoparticles composed of elemental palladium have been isolated from the reaction media and analyzed using transmission electroscopic microscope (TEM), which shows the essential catalysts palladium nanoparticles to have a size of ca. 3.0 nm.
Combined SuzukiCoupling – Wittig Olefination Reaction
in Aqueous Medium
Kyoko Yamamotoa, Masataka Watanabea, Kyoko Idetab, Shuntaro Matakab, and
a Interdisciplinary Graduate School of Engineering Sciences and
b Institute of Materials Chemistry and Engineering, Kyushu University, 6-1, Kasuga-koh-en,
Kasuga-shi, 816-8580, Japan
Reprint requests to Dr. T. Thiemann. E-mail: firstname.lastname@example.org. Fax: (0081) +(0)92-583-7894
Z. Naturforsch. 60b, 1299 – 1307 (2005); received August 25, 2005
Bromoarene carbaldehydes and bromoheteroarene carbaldehydes
The Heck coupling of halobenzenes with various alkenes and the Suzuki cross coupling of halobenzenes with phenylboronic acid were successfully performed in glycerol as the reaction solvent using homogeneous and heterogeneous palladium catalysts. Glycerol is a renewable and recyclable green solvent that is able to dissolve organic substrates, inorganic bases, and palladium complexes, and that allows easy isolation of the reaction product by simple extraction with glycerol-immiscible solvents such as diethyl ether, hexane, and dichloromethane.
In the search of new materials for developing clean catalytic organic reactions, our team engineered graphene based palladium (Pd) nanocomposites and tested them as catalysts for ionic liquid mediated Suzuki cross coupling reaction. The effects of various reaction parameters, such as solvent, base, time and temperature, were investigated for the Suzuki reaction. The optimized protocol was applied to a wide range of substituted aryl/hetroaryl halides along with various aryl boronic acids and afforded the corresponding reaction products in good to excellent yield. The proposed Pd/reduced graphene oxide (rGO) catalyzed Suzuki reaction protocol was also exploited for the synthesis of unique indazole derivatives. The developed catalytic system circumvents the use of phosphine ligands, with an added advantage of easy Pd catalyst recovery up to eight times.
71A D. Mangeron Blvd., 700050, Iasi, Romania; tel: 040-232-21415; fax: 040-232-
271311; e-mail: email@example.com
3“Petru Poni’’ Institute of Macromolecular Chemistry, Department of Electroactive
Polymers, 41A Gr. Ghica Voda Alley, 700487, Iasi, Romania; tel: 040-232-217454;
fax: 040-232-211299; e-mail: firstname.lastname@example.org
(Received: 16 February, 2009; published: 09 April, 2011)
Abstract: Two novel polyazines were successfully synthesized via palladium-
catalyzed Suzukicoupling method of N,N'-bis(5-bromothiophene)-2-aldehyd azine