Catalyzed Suzuki Cross-coupling Reaction Research Articles

Ultrasound promoted Suzuki cross-coupling reactions in ionic liquid at ambient conditions.

Palladium catalyzed Suzuki cross-coupling reactions of halobenzenes including chlorobenzenes with phenylboronic acid have been achieved at ambient temperature (30 degrees C) in the absence of a phosphine ligand using the ionic liquid 1,3-di-n-butylimidazolium tetrafluoroborate [bbim][BF4] with methanol as co-solvent under ultrasonic irradiation.

Sterically Encumbered Porphyrins by Suzuki Reactions of a 5,15-Bis(4,6-dichloropyrimidin-5-yl) Derivative

The high yielding synthesis of novel four picket fence porphyrins via palladium catalyzed Suzuki cross-coupling reactions of 5,15-bis(pyrimidinyl)porphyrin 1 and commercially available arylboronic acids is described.

Synthesis of 6-aryl-2,4-diamino-pyrimidines and triazines using palladium catalysed Suzuki cross-coupling reactions

The high yielding synthesis of 6-aryl-2,4-diaminopyrimidines and triazines via palladium catalysed Suzuki cross-coupling reactions of commercially available 6-chloro-2,4-diaminopyrimidine 1 or 6-chloro-2,4-diaminotriazine 8 and aryl boronic acids are described.

Structural studies on bioactive compounds. Part 29: Palladium catalysed arylations and alkynylations of sterically hindered immunomodulatory 2-amino-5-halo-4,6-(disubstituted)pyrimidines

The immunological agent bropirimine 5 is a tetra-substituted pyrimidine with anticancer and interferon-inducing properties. Synthetic routes to novel 5-aryl analogues of bropirimine have been developed and their potential molecular recognition properties analysed by molecular modelling methods. Sterically challenged 2-amino-5-halo-6-phenylpyrimidin-4-ones (halo=Br or I) are poor substrates for palladium catalysed Suzuki cross-coupling reactions with benzeneboronic acid because the basic conditions of the reaction converts the amphoteric pyrimidinones to their unreactive enolic forms. Palladium-mediated reductive dehalogenation of the pyrimidinone substrates effectively competes with cross-coupling. 2-Amino-5-halo-4-methoxy-6-phenylpyrimidines can be converted to a range of 5-aryl derivatives with the 5-iodopyrimidines being the most efficient substrates. Hydrolysis of the 2-amino-5-aryl-4-methoxy-6-phenylpyrimidines affords the required pyrimidin-4-ones in high yields. Semi-empirical quantum mechanical calculations show how the nature of the 5-substituent influences the equilibrium between the 1H- and 3H-tautomeric forms, and the rotational freedom about the bond connecting the 6-phenyl group and the pyrimidine ring. Both of these factors may influence the biological properties of these compounds.

Palladium catalysed Suzuki cross-coupling reactions in ambient temperature ionic liquids

Palladium catalysed Suzuki cross-coupling reactions have been conducted in the ambient temperature ionic liquid,1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), exhibiting unprecedented reactivities in addition to easy product isolation and catalyst recycling.

Palladium catalyzed cross-coupling reaction of organoboronic acids with β-(perfluoroalkyl)ethyl iodides

Palladium catalyzed Suzuki cross-coupling reaction of β-(perfluoroalkyl)ethyl iodides with organoboronic acids proceeds smoothly to provide the corresponding cross-coupling products in the presence of the weak base NaHCO 3 in aqueous ethylene glycol dimethyl ether (DME) in moderate to good yields.

New strategy for convergent synthesis of trans-fused polyether frameworks based on palladium-catalyzed suzuki cross-coupling reaction

A new strategy for convergent synthesis of trans-fused polyethers based on palladium(0)-catalyzed Suzuki cross-coupling reaction of alkylboranes with cyclic enol triflates has been developed. The present method allows to construct polyether frameworks rapidly and efficiently.

Dendrophanes: Novel Steroid‐Recognizing Dendritic Receptors. Preliminary Communication

AbstractThe H2O‐soluble dendritic cyclophanes (dendrophanes) 3–5 of first to third generation with molecular weights up to nearly 20 kD were synthesized, purified, and characterized. Cyclophane 2, which served as the initiator core (generation zero), was prepared from tetrabromocyclophane 10 in a four‐step sequence which involved as the first transformation a high‐yielding, four‐fold Pd(0)‐catalyzed Suzuki cross‐coupling reaction with 4‐(benzyloxy)‐phenyl‐boronic acid to give 18. The X‐ray crystal‐structure analysis of tetrabromocyclophane 10 displayed an open, nearly rectangular box with opposite aromatic walls being 8.3 and 11.4 Å apart and of suitable size for the incorporation of steroidal substrates. 1H‐NMR Binding titrations in borate‐buffered D2O/CD3OD 1:1 showed that cyclophane‐tetracarboxylate 2 forms 1:1 inclusion complexes with steroids (Table 2). Complexation was found to be enthalpically driven with higher binding affinities measured for the more apolar substrates. 1H‐NMR Titrations in the same solvent also provided clear evidence for core‐selective complexation of testosterone (21) by the dendrophanes 3 (1st), 4 (2nd), and 5 (3rd generation) carrying up to 108 carboxylate surface groups. The stability of the corresponding 1:1 complexes was hardly affected by the size of the dendritic shell, although some generation‐dependent conformational changes in the receptor cavity seemed to take place. Remarkably, host‐guest exchange kinetics in all recognition processes were fast on the 1H‐NMR time scale.

Synthesis of beta-aryl substituted porphyrins by palladium catalyzed Suzuki cross-coupling reactions

β-Bromoporphyrins undergo Suzuki cross coupling reactions with aryl boronic acids to give β-arylporpyrins in high yields.