Carbonylative Suzuki Coupling Reaction Research Articles

Palladium complex supported on the surface of magnetic Fe3O4 nanoparticles: an ecofriendly catalyst for carbonylative Suzuki-coupling reactions.

Diaryl ketone derivatives include well-known compounds with important physiological and biological properties. In order to prepare diaryl ketone derivatives, we constructed a pallidum (0) complex immobilized on Fe3O4 nanoparticles modified with aminobenzoic acid and phenanthroline [Fe3O4@ABA/Phen-DCA-Pd(0)], and evaluated its catalytic performance for carbonylative Suzuki-coupling reactions of aryl iodides with aryl boronic acid in the presence of Mo(CO)6 as the CO source under mild conditions. FT-IR, SEM, TEM, EDX, VSM, TGA, XRD, ICP-OES and Elemental mapping techniques were employed to identify the structure of the Fe3O4@ABA/Phen-DCA-Pd(0) nanocatalyst. Different derivatives of aryl iodides and aryl boronic acids containing withdrawing and donating functional groups were studied for the preparation of diaryl ketones. Also, various derivatives of heteroaryl iodides and boronic acids were used and the desired products were prepared with high yields. The Fe3O4@ABA/Phen-DCA-Pd(0) nanocatalyst was separated magnetically and reused 7 consecutive times without reducing its catalytic activity. VSM, TEM and ICP-OES spectroscopic techniques confirmed that the synthesized Fe3O4@ABA/Phen-DCA-Pd(0) catalyst was still stable and maintained its structure despite repeated reuse.

Palladium supported on MRGO@CoAl‐LDH catalyzed reductive carbonylation of nitroarenes and carbonylative Suzuki coupling reactions using formic acid as liquid CO and H2 source

AbstractIn the present study, a heterogeneous palladium catalyst system, Pd nanoparticles supported on MRGO@CoAl‐LDH, was synthesized and employed in reductive carbonylation of nitroarenes and carbonylative Suzuki coupling reactions using formic acid as CO and H2 source. The as‐obtained heterogeneous catalyst was characterized by Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive X‐ray analysis (EDAX), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The nanocatalyst was reused for 5 cycles with a negligible reduction in the yield of products. All reactions were carried out with high yields and under suitable and safe conditions. Also, we have successfully applied formic acid as a good and safe alternative to CO and H2 gases.

One‐Pot Synthesis of Xanthone by Carbonylative Suzuki Coupling Reaction

AbstractXanthone derivatives have a dibenzo‐y‐pyrone scaffold which has gained great interest in Medicinal Chemistry due to their diverse biological activities. Usually, its synthesis requires multi‐step synthetic routes using harsh conditions and high catalyst loadings. In this communication, we report for the first time a one‐pot synthesis of the xanthone scaffold based on a carbonylative Suzuki coupling. Iodophenol and (2‐methoxyphenyl)boronic acid were coupled under carbon monoxide, generated from a carbon monoxide surrogate. An experimental data‐based model was built to guide the reaction optimization. The optimized conditions were 1 mol% of a pincer complex as palladium catalyst, 5 equivalents of K2CO3 as base, and DMF:water (7 : 3) as solvent. The robustness of the synthetic method, namely in terms of the reactants scope, was also evaluated. This approach provided the xanthone scaffold in high yields and provided a deep insight into the carbonylative Suzuki couplings.

Carbonylative Suzuki coupling reactions catalyzed by ONO pincer–type Pd(II) complexes using chloroform as a carbon monoxide surrogate

Benzoylhydrazone Schiff base–ligated three new ONO pincer–type palladium(II) complexes, [(PdL1(PPh3)] (1), [(PdL2(PPh3)] (2), and [(PdL3(PPh3)] (3), were synthesized by the reaction of the respective ligand, N‐(2‐hydroxybenzylidene)benzohydrazide (HL1), N‐(2‐hydroxy‐3‐methoxybenzylidene)benzohydrazide (HL2), or N‐(5‐bromo‐2‐hydroxybenzylidene) benzohydrazide (HL3), with Pd(OAc)2 and PPh3 in methanol and isolated as air‐stable reddish‐orange crystalline solids in high yields (78%–83%). All three complexes were fully characterized by elemental analysis, Fourier‐transform infrared spectroscopy, UV–Visible, 1H nuclear magnetic resonance (NMR), 13C{1H} NMR, and 31P{1H} NMR spectroscopic studies. The molecular structure of all three complexes was established unambiguously by single‐crystal X‐ray diffraction studies which revealed a distorted square planar geometry of all three complexes. The ONO pincer–type ligands occupied three coordination sites at the palladium, while the fourth site is occupied by the monodentate triphenylphosphine ligand. The catalytic potential of all three complexes was explored in the carbonylative Suzuki coupling of aryl bromides and iodides with arylboronic acids to yield biaryl ketones, using CHCl3 as the source of carbonyl. The reported protocol is convenient and safe as it obviates the use of carbon monoxide (CO) balloons or pressured CO reactors which are otherwise needed for the carbonylation reactions. The methodology has been successfully applied to the synthesis of two antineoplastic drugs, namely, phenstatin and naphthylphenstatin, in good yields (81% and 85%, respectively). Under the optimized reaction conditions, complex 2 exhibited the best catalytic activity in the carbonylative Suzuki couplings. The reported catalysts have wide reaction scope with good functional group tolerance. All catalysts could be retrieved from the reaction after completion and recycled up to three times with insignificant loss in the catalytic activity.

Binuclear Palladium Complex Immobilized on Mesoporous SBA-16: Efficient Heterogeneous Catalyst for the Carbonylative Suzuki Coupling Reaction of Aryl Iodides and Arylboronic Acids Using Cr(CO)6 as Carbonyl Source

In this study, a binuclear palladium complex immobilized on the organo-functionalized SBA-16 was prepared and structurally characterized by routine techniques. Characterizations indicated that the mesostructure of SBA-16 was maintained after the immobilization of palladium complex. Then, the prepared nanomaterial was applied as a heterogeneous catalyst in the carbonylative Suzuki coupling reaction of aryl iodides with arylboronic acids using Cr(CO)6 as carbonyl source. The catalyst was efficiently promoted the coupling reactions of various aryl iodides and arylboronic acids to give the corresponding diaryl ketones in excellent yields. Moreover, the catalyst was readily recovered by filtration and could be reused for seven cycles without losing its structural integrity and catalytic activity.

Carbonylative Suzuki coupling and alkoxycarbonylation of aryl halides using palladium supported on phosphorus‐doped porous organic polymer as an active and robust catalyst

Developing highly active catalysts with the combined advantages of molecular and solid catalysis is considered as the “Holy Grail” in the area of catalysis research. Herein, a phosphorus‐doped porous polymer‐immobilized palladium was successfully developed as an efficient, robust, and recyclable catalyst for the carbonylative Suzuki coupling and alkoxycarbonylation reactions of aryl halides. Rather than just as an immobilizing molecular catalyst, palladium supported on phosphorus‐doped porous organic polymer exhibits even better catalytic performances than that of its analogue homogeneous catalysts in both carbonylation reactions. Moreover, the catalyst can be easily separated and reused for at least 5 times without significant loss in reactivity. Importantly, the catalyst was highly stable under carbonylation reaction conditions, and no palladium nanoparticle was observed even after the 5th reuse.

Efficient in situ N-heterocyclic carbene palladium(ii) generated from Pd(OAc)2 catalysts for carbonylative Suzuki coupling reactions of arylboronic acids with 2-bromopyridine under inert conditions leading to unsymmetrical arylpyridine ketones: synthesis, characterization and cytotoxic activities.

N,N-Substituted benzimidazole salts were successfully synthesized and characterized by 1H-NMR, 13C {1H} NMR and IR techniques, which support the proposed structures. Catalysts generated in situ were efficiently used for the carbonylative cross-coupling reaction of 2 bromopyridine with various boronic acids. The reaction was carried out in THF at 110 °C in the presence of K2CO3 under inert conditions and yields unsymmetrical arylpyridine ketones. All N,N-substituted benzimidazole salts 2a–i and 4a–i studied in this work were screened for their cytotoxic activities against human cancer cell lines such us MDA-MB-231, MCF-7 and T47D. The N,N-substituted benzimidazoles 2e and 2f exhibited the most cytotoxic effect with promising cytotoxic activity with IC50 values of 4.45 μg mL−1 against MDA-MB-231 and 4.85 μg mL−1 against MCF7 respectively.

Pd‐NHC catalysed Carbonylative Suzuki coupling reaction and its application towards the synthesis of biologically active 3‐aroylquinolin‐4 (1H)‐one and acridone scaffolds

We have unfolded a convenient and mild protocol for the synthesis of diaryl ketones via Pd‐ NHC catalysed carbonylative Suzuki coupling reaction. Notably, this method offers advantages like no use of toxic CO gas, shorter reaction time, high yield, and broad substrate scope. Several sensitive functional groups (like‐COMe, ‐COOMe, ‐F, ‐Cl, ‐Br, ‐NH2, ‐CN) are well tolerated in this reaction. In addition, we have also demonstrated a new efficient route for the synthesis of biologically active and pharmaceutically important 2‐substituted 3‐Aroylquinolin‐4(1H)‐ones and acridone scaffolds.

Carbonylative Suzuki Coupling Reaction Catalyzed by a Hydrospirophosphorane Palladium Complex

AbstractA Pd complex with the H‐spirophosphorane ligand, PdCl2{P(OCMe2CMe2O)OC6H4NH2} (Cat. 1), was used as the catalyst in the carbonylative Suzuki coupling of substituted iodobenzenes with arylboronic acids and with sodium tetraphenylborate. Substituted diarylketones were obtained in good to excellent yields and a selectivity over 95 % under 1 atm of CO with 1.5 mol % of the catalyst. The promoting role of the H‐spirophosphorane ligand in the catalytic process was evidenced. We used X‐ray photoelectron spectroscopy, TEM, and 31P NMR spectroscopy to reveal that during the reaction Cat. 1 undergoes transformation into Pd complexes that bear the spirophosphorane ligand or other P ligands formed by its dealkylation and to Pd nanoparticles. All these Pd species contribute to the high productivity of the system.

Denitrogenative Suzuki and carbonylative Suzuki coupling reactions of benzotriazoles with boronic acids.

Unprecedented palladium-catalyzed denitrogenative Suzuki and carbonylative Suzuki coupling reactions of benzotriazoles with boronic acids have been realized, which afforded structurally diverse ortho-amino-substituted biaryl and biaryl ketone derivatives. The key to this success is due to the development of a rationally designed strategy to achieve the ring opening of benzotriazoles with a synergistic activating-stabilizing effect, which enables the in situ generation of the corresponding ortho-amino-arenediazonium species. The present work opens up a new avenue to utilize benzotriazoles as synthetic equivalents of ortho-amino-arenediazoniums, which otherwise could not be directly accessed by existing synthetic methods.

Immobilization of palladium (II) complexes on ethylenediamine functionalized core–shell magnetic nanoparticles: An efficient and recyclable catalyst for aerobic oxidation of alcohols and carbonylative Suzuki coupling reaction

A novel Pd(II) complex immobilized on ethylenediamine-functionalized core–shell magnetic nanoparticles [Fe3O4@SiO2–2N–Pd(II)] was successfully synthesized by a facile procedure, and various characterizations (TEM, XRD, FT-IR, TGA, XPS and VSM) were performed to identify its intrinsic features. The amino groups in two kinds from ethylenediamine-functionalized magnetic nanoparticles (Fe3O4@SiO2–2N) performed as robust anchors and efficient stabilizers during the fabrication of Fe3O4@SiO2–2N–Pd(II). As a heterogeneous phosphine-free Pd(II) complex catalyst, it showed excellent catalytic activity for aerobic oxidation of alcohols, and up to >99% yield of unsymmetrical biaryl ketone was obtained in the carbonylative Suzuki coupling reaction of carbon monoxide, 4-methylbenzeneboronic acid and the 4-iodonitrobenzene. Moreover, the catalyst could be completely recovered by magnetic separation from the reaction mixture and remained unaltered activity even after six repeated cycles.

ChemInform Abstract: A Convenient Palladium‐Catalyzed Carbonylative Suzuki Coupling of Aryl Halides with Formic Acid as the Carbon Monoxide Source.

AbstractThis is the first report of using formic acid as a liquid CO source for the palladium‐catalyzed carbonylative Suzuki coupling reaction of aryl halides with arylboronic acids to give various substituted diaryl ketones.

Carbonylative Suzuki coupling reactions of aryl iodides with arylboronic acids over Pd/SiC

High surface area SiC has been used to prepare a Pd/SiC catalyst using the liquid reduction method, and the resulting catalyst was used for the carbonylative Suzuki coupling reaction of aryl iodides with arylboronic acids. The catalyst was also characterized by X-ray diffraction, inductively coupled plasma-mass spectroscopy and high-resolution transmission electron microscopy. The results of these analyses showed that homogeneous Pd nanoparticles with a mean diameter of 2.8 nm were uniformly dispersed on the SiC surface. Optimization of the reaction conditions for the carbonylative Suzuki coupling reaction, including the solvent, base, pressure, temperature and reaction time, revealed that the model reaction of iodobenzene (1.0 mmol) with phenylboronic acid (1.5 mmol) could reach 90% conversion with a selectivity of 99% towards the diphenyl ketone using 3 wt% Pd/SiC under 1.0 MPa of CO pressure at 100 °C for 8 h with K2CO3 (3.0 mmol) as the base and anisole as the solvent. The Pd/SiC catalyst exhibited broad substrate scope towards the carbonylative Suzuki coupling reaction of aryl iodides with arylboronic acids bearing a variety of different substituents. Furthermore, the Pd/SiC catalyst exhibited good recyclability properties and could be recovered and reused up to five times with the conversion of iodobenzene decreasing only slightly from 90% to 76%. The decrease in the catalytic activity after five rounds was attributed to the loss of active Pd during the organic reaction.

Palladium nanoparticles immobilized onto supported ionic liquid-like phases (SILLPs) for the carbonylative Suzuki coupling reaction

Palladium nanoparticles immobilized onto dication imidazolium–divinylbenzene polymer was an efficient and reusable catalyst for carbonylative Suzuki coupling reaction.

ChemInform Abstract: Palladium(II) Chalcogenolate Complexes as Catalysts for C—C Cross‐Coupling and Carbonylative Suzuki Coupling Reactions.

AbstractThe catalytic activity of palladium chalcogenate complexes is investigated.

Palladium(II) chalcogenolate complexes as catalysts for C[sbnd]C cross-coupling and carbonylative Suzuki coupling reactions

The catalytic activity of palladium chalcogenolate complexes, [PdCl(ECH2CH2NMe2)]3 (E=S or Se), [PdCl(ECH2CH2CH2NMe2)]2 and [PdCl(SeCH2CH2NMe2)(PPh3)] has been investigated in carbonylative Suzuki coupling reactions. The phosphine complex has also been used as a catalyst in CC cross coupling reactions involving an aryl halide and either triaryl bismuth or aryl boronic acid (Suzuki coupling). The catalytic system was also explored for other carbonylation reactions including carbonylative Sonogashira coupling and amino carbonylation reaction. The phosphine complex showed better activity in carbonylative Suzuki coupling reactions than dimeric and trimeric complexes. All the complexes showed comparable activity in Suzuki coupling reactions.

Efficient, recyclable and phosphine-free carbonylative Suzuki coupling reaction using immobilized palladium ion-containing ionic liquid: synthesis of aryl ketones and heteroaryl ketones

The carbonylative Suzuki coupling reaction of aryl and heteroaryl iodides was studied by using immobilized palladium ion-containing ionic liquid (ImmPd-IL). The protocol was optimized with respect to various reaction parameters, applied to a wide variety of substituted aryl/heteroaryl iodides and various aryl/heteroaryl boronic acids with different steric and electronic properties, and afforded the corresponding products in good to excellent yield. This is an efficient, heterogeneous catalyst which avoids the use of phosphine ligands, and its reusability was tested in up to four consecutive cycles. The recycled catalyst was characterized by using XPS analysis.

A Simple, Efficient, and Recyclable Phosphine-Free Catalytic System for Carbonylative Suzuki Coupling Reaction of Aryl and Heteroaryl Iodides

The carbonylative Suzuki cross-coupling reaction of arylboronic acid with aryl and heteroaryl iodides using polymer supported palladium-N-heterocyclic carbene complex (PS-Pd-NHC) as an efficient heterogeneous, recyclable catalyst is described. The developed catalytic system is found to be effective for the carbonylative coupling reaction of aryl, heteroaryl, and bicyclic heteroaryl iodides (5-iodoindole and 3-iodoquinoline) with various arylboronic acid derivatives providing good to excellent yields of the desired products. The protocol is advantageous due to the ease in handling of the catalyst and simple workup procedure, and environmentally benign with effective catalyst recyclability.

Pd/C: An Efficient, Heterogeneous and Reusable Catalyst for Phosphane‐Free Carbonylative Suzuki Coupling Reactions of Aryl and Heteroaryl Iodides

AbstractThe carbonylative Suzuki coupling reaction of aryl boronic acid with different aryl and heteroaryl iodides was carried out to synthesize various unsymmetrical biaryl ketones by using Pd/C as an efficient, heterogeneous and reusable catalyst. The catalyst exhibits remarkable activity, and its reusability was tested up to four consecutive cycles. The reaction is applicable for various aryl and heteroaryl iodides having different steric and electronic properties. It provides good to excellent yield of the desired products. The developed protocol is advantageous with regard to the ease in handling the catalyst and the simple work‐up procedure; it is also an environmentally benign process with effective catalyst recyclability.

Pd‐Catalyzed Carbonylative Cross‐Coupling Reactions of Chloroarene‐Cr(CO)3 Complexes.

AbstractFor Abstract see ChemInform Abstract in Full Text.