Metal Catalyzed Carbonylation Reactions Research Articles

Gold-Catalyzed Alkoxy-Carbonylation of Aryl and Vinyl Iodides.

Herein, for the first time, we disclose the gold-catalyzed alkoxy-carbonylation of aryl and vinyl iodides utilizing ligand-enabled Au(I)/Au(III) redox catalysis. The present methodology is found to be general, efficient, employs mild reaction conditions and showcases a broad substrate scope even with structurally complex molecules. Density functional theory (DFT) calculations revealed mechanistic pathways distinct from those of conventional transition metal-catalyzed carbonylation reactions.

Generation and transformation of α-oxy carbene intermediates enabled by copper-catalyzed carbonylation

Since the Fischer-Tropsch reaction was discovered by Otto Roelen in 1938, transition metal-catalyzed carbonylation reactions come in as one of the most important methods for preparing carbonyl-containing and carbon chain-increased compounds. As a result, the field of carbonylation research has received considerable attention over the past decades and continues to increase. With the continuous development of carbonylation and the in-depth study of the mechanism, more mechanistic details and variations have been revealed, which provide more possibilities for organic synthesis. Recently, copper catalysis has been introduced to the carbonylative functionalization of alkenes, thus enabling the rapid assembly of functionalized carbonyl compounds from simple starting materials. In this Account, we summarize the new findings in the Cu-catalyzed borocarbonylation of alkenes based on the generation and transformation of α-oxy carbene intermediates. We believe that the results presented in this Account will further inspire the design of new carbonylation reactions.

DMF as CO Surrogate in Carbonylation Reactions: Principles and Application to the Synthesis of Heterocycles

Transition metal-catalyzed carbonylation reactions have emerged as one of the most relevant synthetic approaches for the preparation of carbonyl-containing molecules. The most commonly used protocol for the insertion of a carbonyl moiety is the use of carbon monoxide (CO) but, due to its toxic and explosive nature, this process is not suitable at an industrial scale. More recently, the chemistry of CO surrogates has received large attention as a way to use less expensive and more environmentally friendly methods. Among the various CO surrogates, N,N-dimethylformamide (DMF) has been paid greater attention due to its low cost and easy availability. This mini-review gives appealing insights into the application of DMF as a CO surrogate in metal-catalyzed carbonylations; in particular, in the first part we will give a general state of the art of these reactions for the preparation of carbonyl-containing molecules; then, we will take into account all the various synthetic approaches for the metal-catalyzed carbonylative synthesis of heterocycles using DMF as a CO surrogate. Each protocol has been discussed critically in order to screen the best synthetic method and to offer perspective on trends and future directions in this field.

Copper-Catalyzed Carbonylative Coupling of Alkyl Halides.

Transition metal-catalyzed carbonylation reactions represent a direct and atom-economical approach to introduce oxygen functionality into organic compounds, with CO acting as an inexpensive and readily available C1 feedstock. Despite the long history of carbonylation catalysis, including many processes that have been industrialized at bulk scale, there remain several challenges to tackle. For example, noble metals such as Pd, Rh, and Ir are typically used as catalysts for carbonylation reactions, rather than earth-abundant alternatives. Additionally, while carbonylation of C(sp2)-hybridized substrates (e.g., aryl halides) is well-known, carbonylation of unactivated alkyl electrophiles, especially where β-hydride elimination can compete with desired CO migratory insertion at the catalyst site, remains challenging for many systems. Recently, base metal catalysis based on Mn, Co, and other metals has enabled advances in carbonylative coupling of alkyl electrophiles, though the nucleophiles are often limited to alcohols or amines to generate esters or amides as products. Thus, we have targeted base metal-catalyzed carbonylative C-C and C-E (E = N, H, Si, B) coupling reactions as a method for approaching diverse carbonyl compounds of synthetic importance.Initially, we designed a heterobimetallic catalyst platform for carbonylative C-C coupling of alkyl halides with arylboronic esters (i.e., carbonylative Suzuki-Miyaura coupling) to generate aryl alkyl ketones. Subsequently, we developed multicomponent carbonylation reactions of alkyl halides using NHC-Cu catalysts (NHC = N-heterocyclic carbene). These reactions operate by radical mechanisms, converting alkyl halides into either acyl radical or acyl halide intermediates that undergo subsequent C-C or C-E coupling at the Cu site. This mechanistic paradigm is relatively novel in the metal-catalyzed carbonylation area, allowing us to discover a previously unexplored chemical space in carbonylative coupling catalysis. We have successfully developed the following reactions: (a) hydrocarbonylative coupling of alkynes with alkyl halides; (b) borocarbonylative coupling of alkynes with alkyl halides; (c) reductive aminocarbonylation of alkyl halides with nitroarenes; (d) reductive carbonylation of alkyl halides; (e) carbonylative silylation of alkyl halides; (f) carbonylative borylation of alkyl halides. These reactions provide a broad range of valuable products including ketones, allylic alcohols, β-borylenones, amides, alcohols, acylsilanes, and acylborons in an efficient manner. Notably, the preparation of some of these products has previously required multistep syntheses, harsh conditions, or specialized reagents. By contrast, the multicomponent coupling platform that we have developed requires only readily available building blocks and rapidly increases molecular complexity in a single synthetic manipulation.

ChemInform Abstract: Recent Advances in the Transition Metal Catalyzed Carbonylation of Alkynes, Arenes and Aryl Halides Using CO Surrogates

AbstractReview: 133 refs.

Recent advances in the transition metal catalyzed carbonylation of alkynes, arenes and aryl halides using CO surrogates

Transition metal catalyzed carbonylation reactions using carbon monoxide as the C-1 source have occupied an all important position in catalysis which is subsequently related to organic synthesis and industrial synthesis of molecules.

Synthesis of acylphosphonates by a palladium-catalyzed phosphonocarbonylation reaction of aryl iodides with phosphites.

Acylphosphonates are conveniently synthesized from aryl iodides by a palladium-catalyzed reaction with dialkyl phosphites under an atmospheric pressure of carbon monoxide. The reaction demonstrates the first example of the use of phosphorus nucleophiles in related metal-catalyzed carbonylation reactions.

Formic Acid Derivatives as Practical Carbon Monoxide Surrogates for Metal-Catalyzed Carbonylation Reactions

This account describes our findings on formic acid derivatives as practical carbon monoxide (CO) surrogates in synthetic organic chemistry. Among the known CO surrogates, formic acid derivatives are advantageous in terms of their good availability, stability, and ease of handling. We adopted two approaches to expand the synthetic utility of formic acid derivatives. One is the use of formic acid esters for reactions with alkenes based on the finding that substituted imidazoles can function as the ligands in ruthenium-catalyzed hydroesterifications of alkenes. The other approach involves the use of formic acid derivatives for reactions with (hetero)aryl or alkenyl halides based on the finding that phenyl formate undergoes decomposition to give CO and phenol by simply reacting with a weak base such as triethylamine. In addition to phenyl formate, electrophilic formic acid derivatives such as 2,4,6-trichlorophenyl formate and N-formylsaccharin were found to be stable on storage, but highly reactive, even under ambient reaction conditions, functioning as CO-generating compounds. The in situ generated CO can be incorporated efficiently into products under metal catalysis, thus providing a novel carbonylation. Notably, the carbonylation process did not require the use of external gaseous CO, thus significantly enhancing the safety and practicality of the approach. 1 Introduction 2 Ruthenium-Catalyzed Hydroesterification 3 Palladium-Catalyzed Aryloxycarbonylation 3.1 Decomposition of Phenyl Formate under Weakly Basic Conditions 3.2 Aryloxycarbonylation Using Phenyl Formate 3.3 Room-Temperature Aryloxycarbonylation Using 2,4,6-Trichlorophenyl Formate 4 Reductive Carbonylation Using N-Formylsaccharin 5 Fluorocarbonylation Using N-Formylsaccharin 6 Conclusion

ChemInform Abstract: Carbonylation Reactions of Alkyl Iodides Through the Interplay of Carbon Radicals and Pd Catalysts

AbstractReview: 81 refs.

Carbonylation Reactions of Alkyl Iodides through the Interplay of Carbon Radicals and Pd Catalysts

Numerous methods for transition metal catalyzed carbonylation reactions have been established. Examples that start from aryl, vinyl, allyl, and benzyl halides to give the corresponding carboxylic acid derivatives have all been well documented. In contrast, the corresponding alkyl halides often encounter difficulty. This is inherent to the relatively slow oxidative addition step onto the metal center and subsequent β-hydride elimination which causes isomerization of the alkyl metal species. Radical carbonylation reactions can override such problems of reactivity; however, carbonylation coupled to iodine atom transfer (atom transfer carbonylation), though useful, often suffers from a slow iodine atom transfer step that affects the outcome of the reaction. We found that atom transfer carbonylation of primary, secondary, and tertiary alkyl iodides was efficiently accelerated by the addition of a palladium catalyst under light irradiation. Stereochemical studies support a mechanistic pathway based on the synergic interplay of radical and Pd-catalyzed reaction steps which ultimately lead to an acylpalladium species. The radical/Pd-combined reaction system has a wide range of applications, including the synthesis of carboxylic acid esters, lactones, amides, lactams, and unsymmetrical ketones such as alkyl alkynyl and alkyl aryl ketones. The design of unique multicomponent carbonylation reactions involving vicinal C-functionalization of alkenes, double and triple carbonylation reactions, in tandem with radical cyclization reactions, has also been achieved. Thus, the radical/Pd-combined strategy provides a solution to a longstanding problem of reactivity involving the carbonylation of alkyl halides. This novel methodology expands the breadth and utility of carbonylation chemistry over either the original radical carbonylation reactions or metal-catalyzed carbonylation reactions.

ChemInform Abstract: Operando Spectroscopy in Catalytic Carbonylation Reactions

AbstractReview: 124 refs.

Operando Spectroscopy in Catalytic Carbonylation Reactions

Over the years, in situ spectroscopic studies have contributed largely to an in-depth mechanistic understanding of many homogeneously catalyzed reactions. This review discusses the application of operando spectroscopy such as high pressure infrared and NMR to obtain in-depth mechanistic understanding of transition metal catalyzed carbonylation reactions. Several catalytic reactions of industrial relevance are discussed including rhodium catalyzed hydroformylation, palladium catalyzed alkoxycarbonylation, and copolymerization of CO and alkenes. Also, mechanistic studies of tandem reactions such as rhodium catalyzed hydroaminomethylation and hydroformylation-hydrogenation are included. In addition, the effects of alternative media such as supercritical CO2 and ionic liquids are discussed.

Palladium‐Catalyzed Carbonylation of Polychlorinated Pyridines. A Simple Laboratory Approach to Metal Catalyzed Carbonylation Reactions.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Palladium-catalyzed Carbonylation of Polychlorinated Pyridines. A Simple Laboratory Approach to Metal Catalyzed Carbonylation Reactions

The palladium-catalyzed carbonylation reactions of pentachloropyridine and 2,3,4,5-tetrachloropyridine were investigated in alcoholic or aqueous solvent. The high boiling alcohol 2-ethyl-1-hexanol was an effective carbonylation solvent above 100 °C at 1 atm of CO, representing a convenient and simple method for carrying out transition metal catalyzed carbonylation reactions using standard laboratory glassware.