Carbon dioxide as a C1 building block. Mechanism of palladium-catalyzed carboxylation of aromatic halides
01 Aug 1992-Journal of the American Chemical Society (American Chemical Society)-Vol. 114, Iss: 18, pp 7076-7085
TL;DR: In this article, the reduction of aryl halides in the presence of stoichiometric amounts of carbon dioxide and catalytic amounts of Pd II Cl 2 (PPh 3 ) 2 has been reported to result in the formation of the corresponding carboxylic acids.
Abstract: The reduction of aryl halides in the presence of stoichiometric amounts of carbon dioxide and catalytic amounts of Pd II Cl 2 (PPh 3 ) 2 has been previously reported to result in the formation of the corresponding carboxylic acids. It is shown here that the mechanism proceeds via a catalytic cycle initiated by the one-step, two-electron reduction of the divalent palladium complex followed by oxidative addition of the aryl halide to the resulting poorly ligated zerovalent palladium center «Pd 0 (PPh 3 ) 2 », to afford the corresponding σ-arylpalladium(II) intermediate
Citations
More filters
TL;DR: Reaction Mechanism, Synthesis of Urea and Urethane Derivatives, and Alcohol Homologation 2382 10.1.
Abstract: 4.3. Reaction Mechanism 2373 4.4. Asymmetric Synthesis 2374 4.5. Outlook 2374 5. Alternating Polymerization of Oxiranes and CO2 2374 5.1. Reaction Outlines 2374 5.2. Catalyst 2376 5.3. Asymmetric Polymerization 2377 5.4. Immobilized Catalysts 2377 6. Synthesis of Urea and Urethane Derivatives 2378 7. Synthesis of Carboxylic Acid 2379 8. Synthesis of Esters and Lactones 2380 9. Synthesis of Isocyanates 2382 10. Hydrogenation and Hydroformylation, and Alcohol Homologation 2382
3,203 citations
Pacific Northwest National Laboratory1, California Institute of Technology2, Princeton University3, Humboldt University of Berlin4, Pennsylvania State University5, Brookhaven National Laboratory6, University of California, Riverside7, University of Illinois at Urbana–Champaign8, United States Department of Energy9, University of California, Berkeley10, University of Toronto11, University of Michigan12, University of Amsterdam13, Utah State University14, Max Planck Society15, Louisiana State University16
TL;DR: Providing a future energy supply that is secure and CO_2-neutral will require switching to nonfossil energy sources such as wind, solar, nuclear, and geothermal energy and developing methods for transforming the energy produced by these new sources into forms that can be stored, transported, and used upon demand.
Abstract: Two major energy-related problems confront the world in the
next 50 years. First, increased worldwide competition for
gradually depleting fossil fuel reserves (derived from past
photosynthesis) will lead to higher costs, both monetarily and politically. Second, atmospheric CO_2 levels are at their highest recorded level since records began. Further increases are predicted to produce large and uncontrollable impacts on the world climate. These projected impacts extend beyond climate to ocean acidification, because the ocean is a major sink for atmospheric CO2.1 Providing a future energy supply that is secure and CO_2-neutral will require switching to nonfossil energy sources such as wind, solar, nuclear, and geothermal energy and developing methods for transforming the energy produced by these new sources into forms that can be stored, transported, and used upon demand.
1,651 citations
TL;DR: The electrochemical formation of the aryl-substrate bond is discussed for aromatic substrates, heterocycles, other multiple bond systems, and even at saturated carbon substrates.
Abstract: Arylated products are found in various fields of chemistry and represent essential entities for many applications. Therefore, the formation of this structural feature represents a central issue of contemporary organic synthesis. By the action of electricity the necessity of leaving groups, metal catalysts, stoichiometric oxidizers, or reducing agents can be omitted in part or even completely. The replacement of conventional reagents by sustainable electricity not only will be environmentally benign but also allows significant short cuts in electrochemical synthesis. In addition, this methodology can be considered as inherently safe. The current survey is organized in cathodic and anodic conversions as well as by the number of leaving groups being involved. In some electroconversions the reagents used are regenerated at the electrode, whereas in other electrotransformations free radical sequences are exploited to afford a highly sustainable process. The electrochemical formation of the aryl–substrate bond ...
510 citations
TL;DR: The ability of carbon dioxide to act as a ligand in transition metal complexes is now well documented and several coordination modes of CO2 have been described as mentioned in this paper, but activation by coordination is not a necessary prerequisite for catalytic conversion of CO 2 to useful chemicals.
460 citations
TL;DR: Recent carbon-carbon bond forming reactions of carbon dioxide with alkenes, alkynes, dienes, aryl zinc compounds, aRYl boronic esters, aryan halides, and arenes having acidic C-H bonds are reviewed in which transition-metal catalysts play an important role.
446 citations