Carbonylative Cross-coupling Reaction Research Articles

Three-component carbonylative Michael addition of aryl bromides using abundant metal-carbonyl under light

Carbonyl compounds are widely found in various chemical reactions and natural products. Herein, a light-driven carbonylative cross-coupling reaction of bromobenzene was reported. Co2(CO)8 was used as an abundant solid carbonyl source to synthesize various Michael addition products with high yields. This reaction has broad substrates scope with good functional group tolerance. The mechanism study indicated that the reaction is achieved by the formation of benzoyl radical from homolytic C–Co cleavage under irradiation.

Development of non-gaseous palladium-catalyzed carbonylative cross-coupling reaction

Development of non-gaseous palladium-catalyzed carbonylative cross-coupling reaction

1-Iodoglycal: A Versatile Intermediate for the Synthesis of d-Glyco Amides and Esters Employing Carbonylative Cross-Coupling Reaction.

In this study, we present the development of two catalytic processes: a Pd-PEPPSI-catalyzed aminocarbonylation and a Pd(OAc)2-Xantphos-catalyzed alkoxycarbonylation of d-glycals, utilizing carbonylative cross-coupling reactions. We explored successfully various types of aromatic amines, as well as alkyl amines and amino acids, to synthesize new d-glycal amides. However, we observed limitations in the reactivity of alkyl and heteroaromatic amines. The processes enabled the synthesis of 20 novel C1-branched glycoamides and 7 new d-gluco esters.

Co2(CO)8 as a CO-source for Pd-catalyzed Carbonylations: An Update

Abstract: Palladium-catalyzed carbonylative cross-coupling reactions with various carbon monoxide (CO) sources cultivate competent routes for the synthesis of bulk and value-added chemicals. However, the practical use of this odorless, inflammable, lethal gas has always raised a concern for chemists. The attention and advancement of various CO-surrogates is surely wel-comed as a green alternative to CO-gas. However, the main concern lies in the suitability and scalability of these CO-surrogate-driven reactions. Literature showed the progress of various ways to make in-situ CO from these CO surrogates. One of the most convenient sources is using metal carbonyls which are already known to lose CO easily. Among all the kinds, Mo(CO)6 gained much popularity but its toxic nature and demand for high temperatures restricted its use. However, Co2(CO)8 is popular as a catalyst but as an in-situ CO-source reports are scarce. This low-melting CO-releaser was found effective in flourishing aminocarbonylation, alkoxycar-bonylation, and reductive carbonylation under mild conditions. This mini-review portrays the recent developments of palladium-catalyzed carbonylation reactions using Co2(CO)8 as a CO source.

Carbon monoxide surrogates for palladium-catalyzed Suzuki-Miyaura and Sonogashira carbonylative cross-coupling reactions

Palladium-catalyzed Suzuki-Miyaura and Sonogashira reactions are probably the best methods to create new sp2-sp2 and sp2-sp chemical bonds starting from aryl halides and aryl boronic acids or terminal alkynes. These cross-couplings are generally promoted by a palladium-based catalyst and due to their potentialities, they have been deeply investigated. In particular, the carbonylative version of this reactions is widely used for the synthesis of conjugated diaryl and alkynyl ketones, biologically active compounds, and important building blocks for the synthesis of pharmaceuticals, and organic materials. The insertion of a carbon monoxide molecule is generally achieved by means of high pressure of CO but nowadays the severe toxicity of this gas has led to the development of CO surrogates which must be non-toxic and easy to handle. In this context, the aim of this review is to give a detailed comprehensive overview of the scientific literature regarding carbonylative Suzuki-Miyaura and Sonogashira reactions performed employing a CO source. The content of this review will be divided into two main chapters according to the different approach to CO generation, i.e., -in situ and ex situ technique. For each chapter, a systematic analysis of the nature of the CO surrogate will be reported.

Nickel-Catalyzed Highly Selective Reductive Carbonylation Using Oxalyl Chloride as the Carbonyl Source

Nickel-catalyzed carbonylative cross-electrophile coupling which emerges as a powerful, efficient, and low-cost method for constructing challenging carbonyl derivatives has attracted increasing attention of organic chemists. To avoid the generation of a poisonous, volatile, and inert nickel carbonyl complex, it is critical to develop an efficient, cheap, and easily available CO surrogate. Oxalyl chloride, a cheap commercially available chemical, is one of the most versatile organic reagents used in chemical reactions. In this work, high chemoselectivity can be achieved with a 1:1:1 ratio of Ar–I to alkyl-I to oxalyl chloride. A wide range of alkyl aryl ketones which present an important class of molecules in synthetic and medicinal chemistry are accessed from alkyl halides, aryl iodides, under mild conditions. Primary and secondary alkyl iodides were suitable substrates. Various functional groups were well tolerated, affording up to 90% yields. This protocol was also used in the derivatization of natural products and drug molecules. Mechanistic investigation indicates that the reaction of Zn and oxalyl chloride under mild reaction conditions could release CO slowly. This knowledge should be useful for the further development of multicomponent carbonylative cross-coupling reactions.

Palladium-Catalyzed Carbonylative Synthesis of Diaryl Ketones from Arenes and Arylboronic Acids through C(sp2)-H Thianthrenation.

The development of mild methodology for converting inert C-H bonds to value-added molecules has been an attractive research topic during the last few decades as it offers efficient preparation. Meanwhile, diaryl ketones hold potent applications in antitumor drugs, the agrochemical industry, and synthetic chemistry. Herein, we report versatile palladium-catalyzed carbonylative cross-coupling reactions of aryl thianthrenium salts with arylboronic acids. Arenes were transformed site selectively via C(sp2)-H thianthrenation, and various desired diaryl ketones were produced in good to excellent yields.

Iron‐Catalyzed Alkoxycarbonylation of Alkyl Bromides via a Two‐Electron Transfer Process

Transition metal-catalyzed carbonylative cross-coupling reactions are some of the most widely used methods in organic synthesis. However, despite the obvious advantages of iron as an abundant and low toxicity transition metal catalyst, its practical application in carbonylation reaction remains largely unexplored. Here we report our recent study on Fe-catalyzed alkoxycarbonylation of alkyl halides. Mechanistic studies indicate that the reaction is catalyzed by an in situ generated Fe2- complex. This low-valent iron species activates alkyl bromides via a distinctive two-electron transfer (TET) process, whereas it proceeds via a single electron transfer (SET) process for alkyl iodides which is consistent with literature.

Carbonylative Cross-Coupling Reaction of Allylic Alcohols and Organoalanes with 1 atm CO Enabled by Nickel Catalysis.

A nickel-catalyzed three-component carbonylative cross-coupling reaction of allylic alcohols and organoalanes with CO at atmospheric pressure is reported, enabling the expedient formation of β,γ-unsaturated ketones with broad scope. Particularly, the chemoselective allylic carbonylation of diols further highlights the practicability of this protocol. The leverage of organoalanes as both the coupling components and the activators for the alcohol functionalization is crucial for this method, thus no extraneous activators are required.

Synthesis of Sugar-Based Enones and Their Transformation into 3,5-Disubstituted Furans and 2-Acyl-Substituted 1,2,3-Trideoxy Sugars in the Presence of Lewis Acids.

Pd-catalyzed carbonylative cross-coupling reactions of 2-iodoglycals have been developed for the synthesis of sugar-based arylones and ynones using formic acid as the carbonyl source. Whereas acetyl-protected arylones lead to the formation of highly substituted furan derivatives in the presence of Lewis acid, benzyl-protected arylones furnished the 3-deoxy sugar derivative. In the presence of nucleophiles, an attack took place on the C-1 or C-3 carbon regio- and stereoselectively depending on the nature of the nucleophiles.

Efficient synthesis of carbon-11 labelled acylsulfonamides using [11C]CO carbonylation chemistry.

Herein, a novel method for carbon-11 labeling of acyl sulfonamides by a one-step insertive [11C]CO carbonylative cross-coupling reaction between aryl halides and sulfonamides is presented. Various model compounds as well as drug molecules LY573636 (tasisulam) and ABT-199 were obtained in excellent yields. This method provides a valuable and widely applicable contribution to the continuously expanding radiochemical toolbox for PET research.

In situ palladium/N-heterocyclic carbene complex catalyzed carbonylative cross-coupling reactions of arylboronic acids with 2-bromopyridine under CO pressure: efficient synthesis of unsymmetrical arylpyridine ketones and their antimicrobial activities

The carbonylative Suzuki cross-coupling of 2-bromopyridine with various boronic acids to prepare unsymmetrical arylpyridine ketones has been carried out using palladium/N-heterocyclic carbene complexes as catalysts prepared in situ. The selectivity and the rate of these reactions are highly dependent on the conditions, i.e., nature of the palladium catalyst precursor, solvent, temperature and CO pressure. The main side-products arise from direct, non-carbonylative cross-coupling. Under the optimum conditions, arylpyridine ketones are recovered in high yields (60–88%). The antibacterial activities of the corresponding benzimidazole salts 2 were tested against Gram positive and negative bacteria using the agar dilution procedure, and their IC50 values have been determined.

Palladium-Catalyzed Molybdenum Hexacarbonyl-Mediated Gas-Free Carbonylative Reactions

This account summarizes Pd(0)-catalyzed Mo(CO)6-mediated gas-free carbonylative reactions published in the period October 2011 to May 2018. Presented reactions include inter- and intramolecular carbonylations, carbonylative cross-couplings, and carbonylative multicomponent reactions using Mo(CO)6 as a solid source of CO. The presented methodologies were developed mainly for small-scale applications, avoiding the problematic use of gaseous CO in a standard laboratory. In most cases, the reported Mo(CO)6-mediated carbonylations were conducted in sealed vials or by using two-chamber solutions.1 Introduction2 Recent Developments2.1 New CO Sources2.2 Two-Chamber System for ex Situ CO Generation2.3 Multicomponent Carbonylations3 Carbonylations with N and O Nucleophiles4 Carbonylative Cross-Coupling Reactions with Organometallics5 Carbonylative Cascade Reactions6 Carbonylative Cascade, Multistep Reactions7 Summary and Outlook

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.

Palladium-Catalyzed Carbonylative Cross-Coupling Reaction between Aryl(Heteroaryl) Iodides and Tricyclopropylbismuth: Expedient Access to Aryl Cyclopropylketones

The carbonylative cross-coupling reaction between aryl and heteroaryl iodides and tricyclopropylbismuth is reported. The reaction is catalyzed by (SIPr)Pd(allyl)Cl, a NHC-palladium(II) catalyst, operates under 1 atm of carbon monoxide and tolerates a wide range of functional groups. The use of lithium chloride was found to provide higher yields of the desired aryl cyclopropylketones. The conditions were also applied to the carbonylative cross-coupling of an iodoalkene to afford the corresponding alkenyl cyclopropylketone.

An Overview of the Synthesis of Highly Versatile N-Hydroxysuccinimide Esters

N-Hydroxysuccinimide esters (NHS-esters) are important and widely used tools in various areas of chemistry including peptide synthesis, bioconjugate chemistry, functionalized materials and polymers. The usual strategy employed to prepare these active esters generally relies on the coupling reaction with a carboxylic acid and N-hydroxysuccinimide in the presence of a coupling agent. However, more recently, many other efficient strategies have emerged in the literature. This short review covers the literature devoted to the preparation of these valuable N-hydroxysuccinimide esters. 1 Introduction 2 N-Hydroxysuccinimide Coupling Reaction with Activated Carboxylic Acids 3 Carboxylic Acid Coupling Reaction with Activated N-Hydroxysuccinimide 4 Alcohol and Aldehyde Coupling Reaction with N-Hydroxysuccinimide under Oxidizing Conditions 5 Carbonylative Cross-Coupling Reaction 6 Conclusion

ChemInform Abstract: Transition Metal‐Free, Iodide‐Mediated Domino Carbonylation—Benzylation of Benzyl Chlorides with Arylboronic Acids under Ambient Pressure of Carbon Monoxide.

A conceptually distinct approach toward the synthesis of 1,2,3-triarylpropan-1-one by NaI-catalyzed domino carbonylation–benzylation of unactivated benzyl chlorides with arylboronic acids has been developed under ambient pressure of CO gas. The novel method represents a significant improvement over the traditional palladium-catalyzed carbonylation: the catalyst NaI is abundant, inexpensive, and bench stable, the reaction conditions are much milder, and the use of ligands and the costly need to remove metallic impurities from the end products are avoided. This apparently transition-metal-free process offers a new strategy for carbonylative cross-coupling reactions of C(sp3) halides.

Synthesis of aromatic β-keto esters via a carbonylative Suzuki–Miyaura coupling reaction of α-iodo esters with arylboronic acids

Aromatic β-keto esters were synthesized via a carbonylative cross-coupling reaction of alkyl iodides and arylboronic acids in the presence of a catalytic amount of Pd catalyst.

Transition-metal-free, ambient-pressure carbonylative cross-coupling reactions of aryl halides with potassium aryltrifluoroborates

We disclose an unprecedented transition-metal-free carbonylative cross coupling of aryl halides with potassium aryl trifluoroborates even at atmospheric pressure of carbon monoxide. This protocol is efficient, operationally simple, and shows wide scope with regard to both aryl halides and potassium aryl trifluoroborates containing a series of active functional groups.

Preparation of recoverable Fe3O4/PPy–PdII catalysts for carbonylative cross-coupling reactions

The hierarchical porous Fe3O4/PPy–PdII catalyst has been synthesized using Fe3O4 microspheres both as chemical template and oxidant source under sonication. The catalyst characterized by TEM, XRD, FT-IR, XPS and vibrating sample magnetometry (VSM). The catalyst showed high reactivity for the carbonylative cross-coupling reaction of aryl iodides with arylboronic acids. This newly developed catalyst could be easily recovered and revealed high efficiency and high stability under the reaction conditions and during recycling stages.