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With the aim of developing efficient flow-through microreactors for high-throughput organic synthesis, in this work, microreactors were fabricated by chemically immobilizing palladium-, nickel-, iron-, and copper-based catalysts onto ligand-modified poly(glycidyl methacrylate-co-ethylene dimethacrylate) [poly(GMA-co-EDMA)] monoliths, which were prepared inside a silicosteel tubing (10 cm long with an inner diameter of 1.0 mm) and modified with several ligands including 5-amino-1,10-phenanthroline (APHEN), iminodiacetic acid (IDA), and iminodimethyl phosphonic acid (IDP). The performance of the resulting microreactors in Suzuki?Miyaura cross-coupling reactions was evaluated, finding that the poly(GMA-co-EDMA) monolith chemically modified with 5-amino-1,10-phenanthroline as a binding site for the palladium catalyst provided an excellent flow-through performance, enabling highly efficient and rapid reactions with high product yields. Moreover, this monolithic microreactor maintained its good activity and efficiency during prolonged use.

The photochemical fragmentation of N-aroylsulfonamides 9 (ASAP) is a powerful method for the preparation of various biaryls. Compounds 9 are easily accessible in two steps from amines by treatment with arenesulfonyl chlorides and aroyl chlorides. Many of these compounds were prepared for the first time. The irradiation takes place in a previously developed continuous-flow reactor using inexpensive UVB or UVC fluorescent lamps. Isocyanates and sulphur dioxide are formed as the only by-products. The ASAP tolerates a variety of functional groups and is even suited for the preparation of phenylnaphthalenes and terphenyls. The ASAP mechanism was elucidated by interaction of photophysical and quantum chemical (DFT) methods and revealed a spirocyclic biradical as key intermediate.

A strategy for the formation of antimony-carbon bond was developed by nickel-catalyzed cross-coupling of halostibines. This method has been applied to the synthesis of various triaryl- and diarylalkylstibines from the corresponding cyclic and acyclic halostibines. This protocol showed a wide substrate scope (72 examples) and was compatible to a wide range of functional groups such as aldehyde, ketone, alkene, alkyne, haloarenes (F, Cl, Br, I), and heteroarenes. A successful synthesis of arylated stibine 3 a in a scale of 34.77 g demonstrates high synthetic potential of this transformation. The formed stibines (R3Sb) were then used for the palladium-catalyzed carbon–carbon bond forming reaction with aryl boronic acids [R?B(OH)2], giving biaryls with high selectivity, even the structures of two organomoieties (R and R′) are very similar. Plausible catalytic pathways were proposed based on control experiments.

A N-heterocyclic carbene (NHC) ligand, L1 bearing a pendant phosphonate ester group is used to prepare two new NHC-Pd(II) complexes, [Pd(L1)2I2] (1) and [Pd(L1)(py)I2] (2) (py = pyridine). Hydrolysis of phosphonate ester group in 2 results another Pd(II)-NHC complex, [Pd(L2)(py)I2] (3) where a phosphonic acid group is attached to the NHC ligand L2. All the three complexes are characterized by analytical and spectroscopic studies while the molecular structures of 1-2 are also determined by single crystal X-ray diffraction measurement. The catalytic efficacies of 1-3 in Suzuki-Miyaura cross coupling reactions of aryl halides and aryl boronic acid are investigated. DFT calculations were performed to decipher the role phosphonate ester or phosphonic acid substituents on the catalytic efficacy.

The actually direct Suzuki-Miyaura coupling with "protected" R-B(dan) (dan = naphthalene-1,8-diaminato) was demonstrated to smoothly occur without in situ deprotection of the B(dan) moiety. The use of t-BuOK (Ba(OH)2 in some cases) as a base under anhydrous conditions is the key to the successful cross-coupling, where R-B(dan) is readily converted into a transmetalation-active borate-form, regardless of the well-accepted diminished boron-Lewis acidity.

This work examines how N-donor bridged spacer ligands affect N-heterocyclic carbene (NHC) palladium complexes catalytic activities for Suzuki coupling reaction. Different degrees of structural flexibility binuclear NHC palladium complexes were synthesized. The more flexible nitrogen-based alkyl chain ligand shows similar performance with cycloamine counterparts in the Suzuki coupling reaction. Suzuki coupling examples were used in air and ambient temperature to reach moderate to completion yields in short time. Density functional theory calculations showed that the chelate effect, associated with a single Pd complex mechanism, plays a fundamental role in the pre-catalysis stage, supporting a reasonable of the kinetic activity observed experimentally.

A supramolecular catalytic ensemble HP-T?Au-Fe3O4 supported by highly branched assemblies of hexaphenylbenzene (HPB) derivatives has been developed. The as-prepared HP-T?Au-Fe3O4 nanohybrid material serves as an efficient catalytic system to prepare biaryl derivatives through the Kumada cross-coupling reaction using aryl chlorides as one of the coupling partners under mild reaction conditions (visible light irradiation, aqueous media, aerial conditions, short reaction time). Through the cooperative effect of Au NPs and Fe3O4 NPs, dual activation of aryl chlorides for the generation of aryl radical intermediates is achieved. On the other hand, oligomeric assemblies contributed significantly to the enhancement of the reaction rate and yield of the product by facilitating the reductive elimination step. Different mechanistic studies confirm the involvement of Au NPs, Fe3O4 NPs and oligomeric assemblies in the synergistic and balanced operation of HP-T?Au-Fe3O4 nanohybrid materials in the efficient completion of the catalytic cycle of the Kumada coupling reaction. Being magnetic, the catalytic ensemble could be recycled for up to five catalytic cycles. The as-prepared supramolecular photocatalytic ensemble also works efficiently in Heck coupling reactions involving aryl chlorides and aryl iodides as the coupling partner.

A recyclable and non-phosphine solid palladium (II) catalyst was prepared and characterized by HR-MS, FT-IR, XPS, EDS, TGA, SEM, TEM and ICP. The Pd-catalyst exhibited high-performance catalytic activity in Suzuki and Heck C-C coupling reactions in an environmentally benign water medium. Further, the Pd-catalyst (Z4) can be reused for 15 times with little decrease of activity through simple and efficient recovery. In addition, the turn-over number (TON) of Pd- catalyst can reach 380 at room temperature. These results proved that the Pd-catalyst has a stable structure and can be recycled many times, making the process sustainable.

The development of a cross-coupling reaction protocol between aryl ethers and Grignard reagents catalyzed by carbodicarbene (CDC) nickel complexes to afford biaryl compounds through C–O cleavage is reported. Aromatic substrates featuring a broad range of electron neutral, donating, or withdrawing groups are introduced at the desired position. The method has proven effective over a wide range of naphthyl methyl ethers, anisoles, and Grignard reagents. The robustness of the protocol is validated by performing multiple cleavage reactions, gram scale synthesis, and arylation of a dimethoxy esterdiol derivative.

The invention relates to methods for synthesizing a biarylic compound from two arene compounds, comprising the step of reacting said arene compounds in the presence of an ordered, porous material, a catalytic transition metal and an 5 oxidant, wherein the two arene compounds can be different or identical, wherein each of the two different or wherein the identical arene compounds contains at least one H-substituent, and wherein at least one of the arene compounds or wherein the identical arenes are substituted with at least one substituent, different from H.10

Rhodium acetate effectively promotes the carboxylate-directed ortho-arylation of (hetero)aromatic carboxylates with aryl bromides. The main advantage of this phosphine-free, redox-neutral method arises from its efficiency in assembling biologically meaningful electron-rich arylpyridines, which are problematic substrates in known C?H arylations using Pd, Ru, and Ir catalysts. (Figure presented.).

Crosslinked polymer particles carrying hemilabile bis-N,N-aminophosphine (PNP) moieties are obtained by the copolymerization of a PNP-derived monomer bearing four vinyl fragments as cross-linkers, with para-tert-butylstyrene and divinylbenzene, using free radical copolymerization in presence of AIBN, performed in aqueous dispersed medium. This new support was characterized by thermogravimetric analysis, elemental analysis, laser diffraction, solid state NMR. The PNP moiety could allow monochelation to palladium. The resulting insoluble Pd-catalyst revealed to be very active for Suzuki cross-coupling with several substrates, allowing separation of the product from the catalyst by filtration. The final palladium PS-PNP catalyst could be reused for several catalytic cycles.

This disclosure relates to the preparation of diphenyl compounds, especially dimethylbiphenyl compounds, in which there is one methyl group on each ring, and their oxidized analogues. These compounds, and particularly alkylated biphenyl compounds and biphenylcarboxylic acids, alcohols and esters, are useful intermediates in the production of a variety of commercially valuable products, including polyesters and plasticizers for PVC and other polymer compositions.

A process for oxidizing methyl-substituted biphenyl compounds comprises contacting a mixture comprising isomers of at least one methyl-substituted biphenyl compound with a source of oxygen, wherein the mixture comprises at least 20 wt% of isomer(s) having a methyl group at a 2-position or a 3-position on at least one benzene ring and at least 50 wt% of isomer(s) having a methyl group at a 4-position on at least one benzene ring, wherein said percentages are based on the total weight of the at least one methylbiphenyl compound in the mixture.

The effects of metal-modified acidic co-supports on the hydrodesulfurization (HDS) activity and isomerization selectivity of highly refractory organosulfur compounds such as 4,6-dimethyldibenzothiophene have been investigated. Y zeolite crystals with high Si/Al ratios and small crystallite sizes were successfully synthesized by a new hydrothermal synthesis approach. The synthesized Y zeolite crystals were ion-exchanged and stabilized. The prepared samples were then modified with different gallium contents using an impregnation method to adjust their acidity properties, and these modified samples were used as co-supports for NiMo sulfide HDS catalysts. The catalyst containing 10 wt.% zeolite Y modified by 2 wt.% gallium (NiMo/2GaY-ASA-A) exhibited the highest HDS activity, with 4,6-dimethyldibenzothiophene (4,6-DMDBT) conversion nearly double the rate of the catalyst without zeolite at 563 K, 4.0 MPa and liquid hourly space velocity (LHSV) of 40 h?1. NiMo/2GaY-ASA-A also exhibited superior isomerization ability, with 3,4′-DMBP, 4,4′DMBP, and 3,6-DMDBT as the main products, indicating that the isomerization pathway was the main reaction route over NiMo/2GaY-ASA-A. The superior catalytic performance is related to the synergistic effect of the proper amount of medium and strong Br?nsted acid sites. The compounds 3,6-DMDBT and 3,7-DMDBT (isomers of 4,6-DMDBT) and 3,4,6-TMDBT and tetra-methyl-DBT (transmethyl products) were detected simultaneously in the HDS product of 4,6-DMDBT for the first time over NiMo/GaY-ASA-A catalysts. Finally, a new reaction network over NiMo/2GaY-ASA-A was proposed.

Pd-catalyzed highly para-selective arylations of monosubstituted simple arenes with arylboronic acids to widely existed biaryls have been developed. Inspired by requisite amide-directing groups in reported selective oxidative couplings, amide ligands, especially DMF, are designed and found to be critical for the selectivity control in current arylations.

A nanosilica (derived from rice husk)-anchored Pd(II)–Schiff base complex has been synthesized and characterized. This immobilized complex has been found to be a very effective and recyclable heterogeneous catalyst for the Suzuki–Miyaura cross-coupling reaction of various aryl halides with arylboronic acid in aqueous medium under mild conditions. The products were identified using 1H NMR and mass spectral studies. This complex can be easily filtered out from the reaction medium and reused up to six times without significant loss of catalytic activity. Since the reaction proceeds under mild conditions in aqueous medium as well as the catalyst being recyclable, it provides an environmentally benign alternative route to the existing protocols for the Suzuki–Miyaura reaction.

Despite the large number of judiciously designed ligands that have been exploited in palladium-catalyzed cross-coupling protocols, the incorporation of ligands bearing appreciable π-acidic properties has remained significantly underexplored. Herein, we demonstrate that well-defined and low-coordinate Pd0 complexes supported by m-terphenyl isocyanides function as competent catalysts for the Suzuki-Miyaura cross-coupling of aryl bromides and arylboronic acids. Two-coordinate Pd(CNArDipp2)2 was active for the coupling of unhindered aryl bromides at room temperature in 2-propanol, while increasing the temperature to 60 °C allowed for the use of mono- or di-ortho-substituted aryl bromides. Oxidative addition of the aryl bromide was shown to proceed via a dissociative mechanism, implicating monoligated Pd(CNArDipp2) as the catalytically active intermediate. Attempts to access this fleeting species via activation of the PdII monoisocyanide PdCl(η3-C3H5)(CNArDipp2) with alkoxide base yielded the dinuclear PdI species (μ-C3H5)(μ-OiPr)[Pd(CNArDipp2)]2. Although dinuclear PdI complexes are often produced as off-cycle species when using complexes of the type PdCl(η3-allyl)L as precatalysts, this represents the first time that the comproportionation product (μ-allyl)(μ-Cl)[PdL]2 has been observed to undergo nucleophilic substitution with alkoxide, despite the fact that activating conditions for these precatalysts typically employ alkoxide bases. Remarkably, this alkoxide complex can undergo β-hydride elimination with expulsion of acetone and propene to produce two equivalents of catalytically active Pd(CNArDipp2), which can self-aggregate to yield the isolable tripalladium cluster Pd3(η2-Dipp-μ-CNArDipp2)3. This cluster is catalytically competent for the Suzuki-Miyaura reaction and functions as a formal source of monoligated Pd(CNArDipp2) in solution.

A focused library of phosphine ligands was constructed for structural optimization. The catalyst can be used to perform the Suzuki-Miyaura cross-coupling reaction of aryl and heteroaryl chlorides.

A novel and recyclable fluorous ethylenediamine was prepared. Together with potassium tert-butoxide, the fluorous ethylenediamine showed a good activity in promoting the coupling of aryl halides with benzene derivatives without the aid of transition-metal catalysts. Furthermore, a chain homolytic aromatic substitution mechanism was proposed in this paper.

We present here an improved Suzuki–Miyaura cross-coupling in WERSA (Water Extract of Rice Straw Ash). We found that, although the reaction can be run in neat water, use of alcoholic co-solvent dramatically enhances the yield and generates in situ PdNPs during the reaction. The PdNPs were characterized by TEM and powder XRD analysis. The rice straw ash was characterized by EDX, Flame photometry, and Ion-Exchange chromatography to reveal a broad range of active metal species. The chemical analysis reports of ash showed the presence of oxides of K, Na, and Ca, which probably in the presence of water produces the corresponding hydroxides responsible for the basicity.

A series of air-stable aminocarbene-like palladium(II) complexes were easily prepared by the reaction of bis-aromaticisocyanide-dichloropalladium(II) with N-arylbenzamidines. 0.1 mol % of the optimal palladium complex 3a showed excellent catalytic activity for Suzuki-Miyaura cross-coupling reaction at room temperature and the desired products were isolated in up to 98% yields. Moreover, a large-scale reaction showed that 0.01 mol % 3a was enough to catalyze the coupling reaction efficiently at room temperature to give the desired product in 93% yield.

Intramolecular carbonyl allylation of α-prenyl or α-geranyl β-arylketosulfones 5 in the presence of molecule sieves (MS) affords substituted benzenes 6-7 in moderate to good yields. The facile transformation proceeds by a synthetic sequence starting with the α-prenylation or α-geranylation of 1 and the Bi(OTf)3-mediated annulation of 5 followed by a sequential desulfonative aromatization or then an intramolecular Friedel-Crafts alkylation. A plausible mechanism has been studied and proposed.

A catalyst system comprising Fe2(OtBu)6 and an N-heterocyclic carbene ligand enables efficient syntheses of (hetero)biaryls from the reactions of aryl Grignard reagents with a diverse spectrum of (hetero)aryl chlorides. Amongst the alkoxide and amide counterions investigated, tert-butoxide was the most effective in inhibiting the homocoupling of arylmagnesiums. This journal is the Partner Organisations 2014.

Complex [K3(phen)8][Cu(NPh2) 2]3 (1, phen = phenanthroline) was isolated from the catalytic C-N cross coupling reaction based on the CuI-phen-tBuOK catalytic system. Complex 1 can react with 4-iodotoluene to give 4-methyl-N,N- diphenylaniline (3a) in 50% yield (based on all available NPh2 - ligands of complex 1). In addition, 1 can also work as an effective catalyst for the C-N coupling reactions under the same reaction conditions, indicating that 1 may be an effective intermediate of the catalytic system. In the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), a radical scavenger, the stoichiometric reaction between complex 1 and 4-iodotoluene was significantly quenched to give a low yield of 12%. The results suggest that the radical path dominates in the reaction, with (phen)KNPh2 as the possible radical source. The structures of 1 and (phen)KNPh2 were both determined by single crystal X-ray diffraction studies.

Di-tert-butyl peroxide can smoothly promote the coupling of aryl halides with benzene derivatives without the aid of transition-metal catalysts through a chain homolytic aromatic substitution mechanism in the presence of potassium tert-butoxide. Radical reasoning: Di-tert-butyl peroxide and potassium tert-butoxide smoothly direct the C-H arylation of unactivated benzene derivatives with aryl halides without the aid of a transition metal. Reactions occur through a base-promoted homolytic aromatic substitution process and involve aryl radicals and aryl radical anions as intermediates. The process to synthesize biaryl compounds is high yielding and practical.

A solvent-free reaction protocol for Suzuki-Miyaura cross-couplings was developed. (Hetero)aryl bromides and chlorides are coupled with pinacol arylboronates in high yields. The reaction is catalyzed by conventional bis(triphenylphosphine)palladium(II) chloride [(PPh3) 2PdCl2] and/or palladium(II) acetate/SPhos [Pd(OAc) 2/SPhos] under air. Copyright

A new strategy for the construction of biaryls by a transition-metal-free process is presented. A sequence of a Grignard reaction, dehydration, and oxidative aromatization affords the desired products in a one-pot fashion. Copyright

Buy one get one free: Concurrent introduction of both iodo- and carbonyl groups, along with the construction of the benzenoid core, has been achieved through an iodine-initiated domino reaction of hepta-1,2-dien-6-yn-4-ols. Moreover, cyclization of hepta-1,2,6-trien-4-ols turns out to also be an efficient pathway toward diversely substituted benzenes. Copyright

An efficient synthesis of biaryls using a Hiyama reaction between aryl iodides and aryltrialkoxysilanes in the presence of a diphenylphosphinomethylpolystyrene-supported palladium catalyst is described. The cross-coupling proceeds in the presence of only 0.1 mol % of supported palladium. The catalyst can be used at least four times and the palladium leaching is extremely low (ca. 1% of the initial amount).

PdCl2(1-methylimidazole)2 was an effective catalyst in neat water for the Suzuki-Miyaura and Mizoroki-Heck reactions of aryl bromides and iodides with, respectively, arylboronic acids and acrylic acid. Under optimal conditions, the products, variously substituted biphenyls and monosubstituted trans-cinnamic acids, respectively, were formed in good to almost quantitative yields.

A well-defined NHC-Pd(II)-Im complex 1 was found to be an effective catalyst for the Suzuki-Miyaura coupling of aryl sulfonates including tosylates and phenylsulfonates with arylboronic acids, giving the desired coupling products in good to high yields. Acceptable yields can also be achieved even by using the less reactive mesylates as the substrates. It is worthy of noting here that this is the first example of NHC-Pd(II) complex-catalyzed Suzuki-Miyaura coupling of aryl sulfonates with arylboronic acids, enriching an inexpensive, convenient, and alternative method for the synthesis of biaryl compounds.

The complex (IPr)Ni(allyl)Cl (IPr = 1,3-bis(2,6-diisopropylphenyl) imidazolidene) catalyzes the cross-coupling reactions of heteroaromatic chlorides with aryl Grignard reagents. Catalyst loadings as low as 0.1 mol % have been used to afford the products in excellent yields. This nickel-based catalytic system also promotes the activation of the CAr-O bond of anisoles in the Kumada-Tamao-Corriu reaction under fairly mild conditions.

Reactions of 1,3-bis(pyridin-2-ylmethyl)-1H-imidazol-3-ium hexafluorophosphate, ([HL1](PF6), L1 = 1,3-bis(pyridin-2-ylmethyl) imidazolylidene) and 1,3-bis(pyridin-2-ylmethyl)-1H-benzimidazol-3-ium hexafluorophosphate ([HL2](PF6), L2 = 1,3-bis(pyridin-2-ylmethyl) benzoimidazolylidene) with cuprous oxide in acetonitrile readily yielded trinuclear complexes [Cu3(L1)3(PF6) 3] (1) and [Cu3(L2)3(PF6) 3] (2). Treatment of 1 with Ni(PPh3)2Cl 2 and Pd(cod)Cl2 gave [Ni(L1)Cl](PF6) (3) and [Pd(L1)Cl](PF6) (4), respectively, due to transmetalation. [Ni(L1)2](PF6)2 (5) was obtained from the reaction of [Cu3(L1)3(PF6)3] and Raney nickel in acetonitrile. All these complexes have been fully characterized. Both 1 and 2 consist of a triangular Cu3 core with each Cu-Cu bond capped by an imidazolylidene group. Each imidazolylidene acts as a bridging ligand in a μ2 mode and is bonded equally to two Cu(I) ions. The pincer nickel and palladium complexes are square-planar and contain a tridentate NCN ligand. Complexes 3 and 4 are efficient catalyst precursors for Kumada-Corriu and Suzuki-Miyaura coupling reactions of aryl halides with organometallic reagents.

A new chemical access has been developed to synthesize biaryls from substituted acetophenones, phenylacetones, dihydrochalcone, and 2-acetylnaphthalene in reasonably good yields at room temperature via a domino reaction sequence of AlCl3 catalyzed cyclization, dehydration, and then oxidation.

A general procedure for cobalt-catalyzed direct C-H arylation of unactivated arenes has been discovered. This method employs aryl halides as the direct coupling partners with arenes without using any Grignard-type reagents. This catalysis opens a new methodology for the preparation of symmetrical as well as unsymmetrical biaryls in a user-friendly approach.

A C2-protected imidazolium salt that generates an abnormal N-heterocyclic carbene (NHC) was applied for the palladium-catalyzed Suzuki-Miyaura coupling reactions. The abnormal NHC precursor promoted the reactions while suppressing homocoupling of aryl boronic acid, which was observed with the corresponding normal NHC precursor. The related well-defined abnormal NHC-based palladium complexes also showed better activity than the normal NHC-based analogues, exhibiting faster reaction rates especially at the initial stage of the reaction.

Aryl trihydroxyborate salts of sodium, an easily accessible and stable alternative source of organoboron species, can efficiently promote Pd-catalyzed ligand-free, on-water Suzuki-Miyaura (SM) coupling reactions at ambient temperature.

The atom-efficient cross-coupling reaction of sodium tetraarylborates with aryl iodides and bromides was reported. The reaction can be performed directly using a catalytic system composed of palladium chloride, sodium carbonate and methanol (PdCl2/Na2CO3/MeOH) under heat-free conditions at room temperature in an open air conditions. The reactions carried out in an atom-efficient way as 4 equiv of aryl halides coupled effectively with 1 equiv of sodium tetraarylborates to furnish 4 equiv of the corresponding functionalized biaryls in good to excellent yields.

A rapid, atom-efficient, cross-coupling reaction of triarylbis- muths with aryl bromides or aryl iodides was reported, and the reaction involves the use of a catalytic amount of polystyrene-supported palladium in the presence of KF as base in DMSO at 105 0C in an open atmosphere. All three aryl groups of the triarylbismuths participated in the reaction and produced polyfunctional biaryls in excellent yields. The polymeric catalyst can be easily separated from the reaction mixture and reused more than 10 times without showing any obvious decrease in activity.

Palladium supported on carbon (Pd/C) has been shown to be an effective catalyst for the cross-coupling of potassium p-tolyltrifluoroborate with a variety of aryl bromides and iodides. Yields ranging from moderate to good were obtained using Pd/C in ethano

The combination of rhodium(I) and N-hetercyclic carbenes (NHC) was found to be effective as a catalyst for cross-coupling reactions of aryl arenesulfonates with arylboronic acids, which gave rise to the desired biaryl compounds in good yields.

The invention is directed to a phosphine compound represented by general formula (1) wherein R' and R" independently are selected from alkyl, cycloalkyl and 2-furyl radicals, or R' and R" are joined together to form with the phosphorous atom a carbon-phosphorous monocycle comprising at least 3 carbon atoms or a carbon-phosphorous bicycle; the alkyl radicals, cycloalkyl radicals, and carbon-phosphorous monocycle being unsubstituted or substituted by at least one radical selected from the group of alkyl, cycloalkyl, aryl, alkoxy, and aryloxy radicals; Cps is a partially substituted or completely substituted cyclopentadien-1-yl group, including substitutions resulting in a fused ring system, and wherein a substitution at the 1-position of the cyclopentadien-1-yl group is mandatory when the cyclopentadien-1-yl group is not part of a fused ring system or is part of an indenyl group. Also claimed is the use of these phosphines as ligands in catalytic reactions and the preparation of these phosphines.

Arene-, phenylmethane- and alkenesulfonyl chlorides are suitable electrophilic reagents in desulfinylative carbon-carbon bond formation cross-coupling reactions with organozinc reagents.

A conceptually and practically simple alternative approach to the use of arylboron species as the organometallic component in cross-coupling processes is described whereby trihydroxyborate salts are isolated and directly employed. The protocol derives practical benefit from the ease and convenience of the isolation and subsequent use of the discrete borate salts, eliminates the need for additional base, and aids the use of correct reaction stoichiometry.

The catalytic cross-coupling of aromatic carboxylic anhydrides or acid chlorides with triarylboroxines has been achieved for the first time under decarbonylation, giving rise to the unsymmetrical biaryls rather than the expected diaryl ketones. This new decarbonylative Suzuki coupling, catalyzed by a [Rh(ethylene)2Cl]2/KF system, can be applied to aromatic, heteroaromatic and vinylic carboxylic anhydrides, potentially opening up new perspectives for the use of carboxylic acid derivatives as substrates in biaryl syntheses.

The palladium-catalyzed cross-coupling reaction of 1-aryltriazenes with aryl- and alkenyltrifluorosilanes occurs readily at room temperature to yield the corresponding biaryl and stilbene products in moderate to good yields. In contrast to the previous re

Arene and phenylmethanesulfonyl chlorides can be cross-coupled with aryl, heteroaryl, and alkenylstannanes with desulfitation in the presence of 10 mol % CuBr·Me2S, 1.5 mol % Pd2dba3, and 5 mol % tri-2-furylphosphine in tetrahydrofuran or toluene under reflux. This extension of the Stille cross-coupling reaction realizes a new and economical method for the generation of C?C bonds. The palladium-catalyzed carbonylative Stille cross-coupling reactions of arenesulfonyl chlorides and organostannanes in the presence of CO (60 bar) at 110 °C in toluene generate the corresponding ketones. Arenesulfonyl chlorides are more reactive than aryl chlorides and aryl bromides in their Stille cross-coupling with organostannanes but less reactive than aryl iodides. The new methods disclosed for the generation of C?C bonds open new possibilities for medicinal chemistry and material sciences. Copyright

(figure presented) The Suzuki-Miyaura coupling of aryl halides (8 varieties) and aryl-or vinylboronic acids (12 varieties) took place in water in the presence of a palladium complex of an amphiphilic polystyrene-poly(ethylene glycol) copolymer resin-supported N-anchored 2-aza-1,3-bis(diphenylphosphino)-propane ligand and potassium carbonate to give uniform and quantitative yields of the corresponding biaryls (96 varieties).

Acid-catalyzed isomerization of dimethylbiphenyls is determined by the relative stability of intermediate carbocations, rather than the neutral products, and may be predicted by a simple semiempirical method (AM1). A general kinetic model for such isomeri