Palladium-catalyzed Suzuki-Miyaura cross-coupling reaction of organoboronic acids with N-protected 4-iodophenyl alanine linked isoxazoles

Suzuki-Miyaura coupling reaction of N-protected 4-iodopheyl alanine isoxazoles with arylboronic acids,catalyzed by palladium,efficiently produce benzyl-N-（4-bipheyl）-2-（3-methyl-5（E）-2-aryl-1-ethenyl-4-isoxazolyl）-amino-2-oxoethyl）carba- mates in good yields.This process is first of its kind to construct carbon-carbon bond formation having biaryl motif on amino acid linked isoxazole moiety.

In situ monitoring of Suzuki-Miyaura cross-coupling reaction by using surface-enhanced Raman spectroscopy on a bifunctional Au-Pd nanocoronal film

Surface-enhanced Raman spectroscopy(SERS), a powerful surface vibrational spectroscopic technique, is ideally suited for in situ monitoring the chemical transformations occurred at surfaces and/or interfaces.For in situ SERS monitoring, a platform integrated both plasmonic and catalytic activity is a prerequisite. Here, we fabricate a bifunctional Au-Pd nanocoronal film for in situ SERS monitoring Suzuki-Miyaura cross-coupling reaction. This excellent bifunctional substrate leads to the coupling of high catalytic activity with a strong SERS effect at the center of two adjacent Au cores and shows fine reproducibility and stability of SERS signals. During investigating the Suzuki reaction with in situ SERS, we found two distinct catalytic kinetic processes resulted from two disparate catalytic sites on a Au-Pd nanocoronal. Comparing with conventional analytical techniques, this work provides a novel approach for studying Suzuki reactions at surfaces and/or interfaces with in situ SERS.

A general strategy for in situ assembly of light-up fluorophores via bioorthogonal Suzuki-Miyaura cross-coupling

Herein we presented a general strategy for in situ assembly of intramolecular charge-transfer(ICT)-based light-up fluorophores via bioorthogonal Suzuki-Miyaura cross-coupling reaction.By introducing iodo group at the appropriate position,five fluorophores with different scaffolds including naphthalimide,coumarin,naphthalene sulfonate,nitrobenzoxadiazole,and acetonaphthone,were designed as bioorthogonal multicolor fluorogenic probes,which could produce significant fluorescence enhancement and high fluorescence quantum yield after Suzuki-Miyaura reaction with aryl boronic acid or boronate.Manipulating the substituents andπscaffold in the fluorophores allows fine-tuning of their photophysical properties.With this strategy,we succeeded in peptide conjugation,no-wash fluorogenic protein labeling,and mitochondria-selective bioorthogonal imaging in live cells.

A New Synthetic Method of （Z）-4-Aryl-but-2-en-l-ols via Suzuki-Miyaura Cross-Coupling Reaction of 4-Substituted 1,2-Oxaborol-2（5H）-ols with Benzyl Bromides

Z and E configuration 4-aryl-but-2-en-1-ols were isolated from several terrestrial plants, and （Z）-4-aryl-but-2- en-l-ols were found to have choleretic activity. Strategies have been reported to synthesize （E）-4-aryl-but-2-en-l- ols with high selectivity. However, there is no method to obtain （Z）-4-aryl-but-2-en-1-ols with high selectivity now. We developed a Suzuki-Miyaura cross-coupling reaction of 1,2-oxaborol-2（5H）-ols with benzyl bromides to synthesize （Z）-4-aryl-but-2-en-1-ols, the products were obtained in up to 94% isolated yield.

An Efficient Palladium and Bis（2-pyridylmethyl）amine-based System for Suzuki-Miyaura Cross-Coupling under Aqueous and Aerobic Condition

A novel PdC12/bis（2-pyridylmethyl）amine-based ligand （1） catalytic system, which is water-soluble and air-stable, has been successfully synthesized and applied for Suzuki-Miyaura cross-coupling reaction. In the presence of catalytic amount of PdCl2/1 system, arylboronic acids can couple with a wide range of aryl halides, including aryl bromides and aryl chlorides. The reactions proceed under mild conditions to give excellent yields, and a wide range of functionalities is tolerated.

Highly Active Pd-PEPPSI Complexes for Suzuki-Miyaura Cross-coupling of Aryl Chlorides:an Investigation on the Effect of Electronic Properties

Three new Pd-pyridine enlianced precatalyst preparation stabilization and initiation(PEPPSI)complexes with halogen groups on the N-heterocyclic carbene and pyridine were prepared.Tlieir structures have been clearly characterized by nuclear magnetic resonance spectroscopy and X-ray single-crystal di fraction.The e fleets of the electronic properties of halogen groups on the catalytic activity in the Suzuki-Miyaura cross-coupling of aryl chlo-rides were investigated.These Pd-PEPPSI complexes could catalyze the cross-coupling reaction efficiently with a low catalyst loading(0.05%,molar ratio)at room temperature and the products were obtained in high yields.

Arylhydrazones Derivatives Containing a Benzothiazole Moiety, Efficient Ligands in the Palladium-Catalyzed Mizoroki-Heck and Suzuki-Miyaura Cross-coupling Reactions under IR Irradiation

A simple arylhydrazone containing the benzothiazole moiety which may be used as an efficient ligand in the palladium-catalyzed Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions, under infrared irradiation as an alternative source of energy, is presented. The reactions proceeded with extremely high efficiency under mild conditions and produced very good yields.

Robust NHC-palladacycles-catalyzed Suzuki-Miyaura cross-coupling of amides via C-N activation

Robust NHC-palladacycles(NHC¼N-heterocyclic carbene)were synthesized and exhibited high catalytic activity towards SuzukiMiyaura cross-coupling reactions between inactive amides with N-acetyl/benzyl substituents and aryl boronic acids,producing diverse ketones in good to excellent yields.This unprecedented and practical palladacycles-catalyzed SuzukiMiyaura cross-coupling of amides with boronic acids via selective C-N bond activation was attributed to the strongσ-donor and weakπ-acceptor properties of acenaphthoimidazolylidene,which may highlight their potential in other challenging coupling transformations involving inactive amides.

Cu(OAc)_2 catalyzed Sonogashira cross-coupling reaction in amines

A simple Cu（OAc）2 catalyzed Sonogashira coupling protocol is presented. It was found that the couplings of a variety of aryl halides with terminal alkynes were conducted smoothly to afford the corresponding desired products in moderate to excellent yields, using Cu（OAc）2 as the catalyst and Et3N as the solvent.

Highly active and stable supported Pd catalysts on ionic liquidfunctionalized SBA-15 for Suzuki–Miyaura cross-coupling and transfer hydrogenation reactions

Highly dispersed palladium nanoparticles were synthesized in the presence of immobilized ionic liquid on mesoporous silica SBA-15.PdNPs(2.4 nm)_me-Im@SBA-15 catalyst was prepared by the reduction using NaBH_4 as the reducing agent with controlled feed rate and has been investigated as ligand-free catalyst for Suzuki–Miyaura cross-coupling reaction at room temperature in aqueous solution under air.PdNPs catalyst was also prepared in situ from PdCl4_me-Im@SBA-15 during the reaction and demonstrated high activity and stability towards nitrobenzene hydrogenation at high temperature. Both catalysts were reusable at least for four recycle processes without significant loss in activity with simple procedure. The catalysts were characterized by TEM, EXAFS, FTIR and XPS.

Polybinaphthyls of (R)-3,3′-Diiodo-2,2′-binaphtho-20-crown-6 with p-Divinylbenzene via Heck Cross-coupling Reaction

The present paper deals with the polymerization of ( R ) 3,3′ diiodo 2,2′ binaphtho 20 crown 6 with \{ p divinylbenzene\} under Heck coupling reaction condition. Both the monomers and the polymer were analyzed by NMR, FTIR, UV, CD, fluorescent spectroscopy, polarimetry, GPC and elemental analysis. The polymer can emit a strong blue fluorescence and is expected to have the potential application in the polarized blue light emitting sensors. The chiral conjugated polymer exhibits a strong Cotton effect in its Circular Dichroism(CD ) spectrum, indicating the high rigidity of the polymer backbone.

Cu-catalyzed cross-couplings under ligandless conditions

The possibility to carry out Cu-catalyzed cross-couplings under ligandless conditions was studied. It was found that by using K3PO4 as the base, the cross-coupling could proceed successfully between aryl iodides and several types of nucleophiles. Aryl bromides were completely inactive under the same reaction conditions.

LOW-VALENT TITANIUM INDUCED REDUCTIVE CROSS-COUPLING REACTION OF ESTERS WITH DIARYL KETONES

The intermotecular coupling reaction of esters with diarvl ketones induced by titanium tetrachtoride and zinc powder was studied.

LOW-VALENT TITANIUM INDUCED REDUCTIVE CROSS-COUPLING REACTION OF ACYL CHLORIDES WITH DIARYL KETONES

Treatment of acyl chlorides and diaryl ketones with an activated Ti(o)reagent,prepared by reduction of TiCl_4 with Zn powder,effects an intermolecular reductive cross-coupling reaction leading to ketones.

Evaluation of TlOH Effect for Pd⁰-Mediated Cross-Coupling of Methyl Iodide and Excess Boronic Acid Ester toward Fabrication of [¹¹C]CH₃-Incorporated PET Tracer

The use of thallium(I) hydroxide (TlOH) as a base is known to extremely accelerate the Suzuki-Miyaura cross-coupling reaction using organoboronic acid or organoboronic acid ester as a substrate. Here, we investigated the effects of TlOH by comparing with other conventional bases such as KOH, K2CO3, and CsF for Pd0-mediated rapid cross-coupling reactions between CH3I and organoborane reagents, such as phenyl-, (Z)-4-benzyloxy-2-butenyl-, and benzylboronic acid pinacol esters under the conditions CH3I/borane/Pd0/base (1:40:1:3) in THF/H2O or DMF/H2O for 5 min with an aim to fabricate a PET tracer efficiently. Consequently, however, the use of TlOH was much less efficient than the other bases for the acceleration of cross-coupling reactions. Thus, it was reconfirmed that the milder and non-toxic conditions using K2CO3 or CsF so far developed by our group were most appropriate for the rapid C-methylations.

The Electrokinetic Cross-Coupling Coefficient: Two-Scale Homogenization Approach

By the two-scale homogenization approach we justify a two-scale model of ion transport through a layered membrane, with flows being driven by a pressure gradient and an external electrical field. By up-scaling, the electroosmotic flow equations in horizontal thin slits separated by thin solid layers are approximated by a homogenized system of macroscale equations in the form of the Poisson equation for induced vertical electrical field and Onsager's reciprocity relations between global fluxes (hydrodynamic and electric) and forces (horizontal pressure gradient and external electrical field). In addition, the two-scale approach provides macroscopic mobility coefficients in the Onsager relations. On this way, the cross-coupling kinetic coefficient is obtained in a form which does involves the &#950 -potential among the data provided the surface current is negligible.

Pd-Catalyzed Unprecedented Cross-Coupling of Mixed Phenols and Halides for the Synthesis of Aromatic Ethers

Phenolic compounds present in medicinal and edible plants such as flavonoids, chalcones, coumarins, quinones, and phenolic acids. The antioxidant potential of phenolic compounds shows potent activities for cancer prevention and its treatment. From a green chemistry point of view, cascade (tandem) reactions are ideal techniques in organic synthesis for building complex structures. Cascade techniques are sometimes observed in coupling reactions under mild conditions with a tolerance of multifunctional groups. It will be interesting to find a cascade type reaction to synthesize polyphenolic ethers. This research project achieves a new cross-coupling method for establishing polyphenolic ethers from mixed phenols and halides in the presence of palladium catalyst in moderate to good yields.