scholarly journals Direct reversible decarboxylation from stable organic acids in dimethylformamide solution

Science ◽  
2020 ◽  
Vol 369 (6503) ◽  
pp. 557-561 ◽  
Author(s):  
Duanyang Kong ◽  
Patrick J. Moon ◽  
Erica K. J. Lui ◽  
Odey Bsharat ◽  
Rylan J. Lundgren
Keyword(s):  
Organic Chemistry ◽  
Carbon Dioxide ◽  
Reactive Intermediates ◽  
Aprotic Solvents ◽  
High Chemical ◽  
Bond Forming ◽  
Synthetic Reactions ◽  
Arylacetic Acids ◽  
Carboxylate Reactivity ◽  
Dimethylformamide Solution

Many classical and emerging methodologies in organic chemistry rely on carbon dioxide (CO2) extrusion to generate reactive intermediates for bond-forming events. Synthetic reactions that involve the microscopic reverse—the carboxylation of reactive intermediates—have conventionally been undertaken using very different conditions. We report that chemically stable C(sp3) carboxylates, such as arylacetic acids and malonate half-esters, undergo uncatalyzed reversible decarboxylation in dimethylformamide solution. Decarboxylation-carboxylation occurs with substrates resistant to protodecarboxylation by Brønsted acids under otherwise identical conditions. Isotopically labeled carboxylic acids can be prepared in high chemical and isotopic yield by simply supplying an atmosphere of 13CO2 to carboxylate salts in polar aprotic solvents. An understanding of carboxylate reactivity in solution enables conditions for the trapping of aldehydes, ketones, and α,β-unsaturated esters.

scholarly journals Direct Reversible Decarboxylation from Stable Organic Acids in Solution

2020 ◽  
Author(s):  
Duanyang Kong ◽  
Patrick Moon ◽  
Erica K. J. Lui ◽  
Odey Bsharat ◽  
Rylan Lundgren
Keyword(s):  
Organic Chemistry ◽  
Organic Acids ◽  
Reactive Intermediates ◽  
Aprotic Solvents ◽  
Reaction Conditions ◽  
High Chemical ◽  
Bond Forming ◽  
Drug Molecules ◽  
Synthetic Reactions ◽  
Synthetic Intermediates

Many classical and emerging methodologies in organic chemistry rely on carbon dioxide extrusion to generate reactive intermediates for subsequent bond-­forming events. Synthetic reactions that involve the microscopic reverse, the carboxylation of reactive intermediates such as organometallic nucleophiles, occur under vastly different reaction conditions. We found that under appropriate conditions chemically stable C(sp3) carboxylates undergo rapid, uncatalyzed reversible decarboxylation in solution. The decarboxylation/carboxylation process occurs through the generation and trapping of otherwise undetectable carbanion intermediates that are largely resistant to protodecarboxylation in the presence of Brønsted acids or to trapping by external electrophiles. Isotopically labelled carboxylic acids, including drug molecules and valuable synthetic intermediates, can be prepared in high chemical and isotopic yield by simply supplying an atmosphere of 13CO2 to carboxylate salts in polar aprotic solvents. Our results indicate that the reversibility of decarboxylation from organic acids should be taken into consideration when designing and executing decarboxylative functionalization processes.

scholarly journals Direct Reversible Decarboxylation from Stable Organic Acids in Solution

2020 ◽  
Author(s):  
Duanyang Kong ◽  
Patrick Moon ◽  
Erica K. J. Lui ◽  
Odey Bsharat ◽  
Rylan Lundgren
Keyword(s):  
Organic Chemistry ◽  
Organic Acids ◽  
Reactive Intermediates ◽  
Aprotic Solvents ◽  
Reaction Conditions ◽  
High Chemical ◽  
Bond Forming ◽  
Drug Molecules ◽  
Synthetic Reactions ◽  
Synthetic Intermediates

Many classical and emerging methodologies in organic chemistry rely on carbon dioxide extrusion to generate reactive intermediates for subsequent bond-­forming events. Synthetic reactions that involve the microscopic reverse, the carboxylation of reactive intermediates such as organometallic nucleophiles, occur under vastly different reaction conditions. We found that under appropriate conditions chemically stable C(sp3) carboxylates undergo rapid, uncatalyzed reversible decarboxylation in solution. The decarboxylation/carboxylation process occurs through the generation and trapping of otherwise undetectable carbanion intermediates that are largely resistant to protodecarboxylation in the presence of Brønsted acids or to trapping by external electrophiles. Isotopically labelled carboxylic acids, including drug molecules and valuable synthetic intermediates, can be prepared in high chemical and isotopic yield by simply supplying an atmosphere of 13CO2 to carboxylate salts in polar aprotic solvents. Our results indicate that the reversibility of decarboxylation from organic acids should be taken into consideration when designing and executing decarboxylative functionalization processes.

scholarly journals Modern Synthetic Methods for the Stereoselective Construction of 1,3-Dienes

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 249
Author(s):  
Raquel G. Soengas ◽  
Humberto Rodríguez-Solla
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Functional Group ◽  
Biological Activities ◽  
Synthetic Methods ◽  
Bond Forming ◽  
Drug Candidates ◽  
The Past ◽  
Wide Range

The 1,3-butadiene motif is widely found in many natural products and drug candidates with relevant biological activities. Moreover, dienes are important targets for synthetic chemists, due to their ability to give access to a wide range of functional group transformations, including a broad range of C-C bond-forming processes. Therefore, the stereoselective preparation of dienes have attracted much attention over the past decades, and the search for new synthetic protocols continues unabated. The aim of this review is to give an overview of the diverse methodologies that have emerged in the last decade, with a focus on the synthetic processes that meet the requirements of efficiency and sustainability of modern organic chemistry.

Catch It If You Can: Copper-Catalyzed (Transfer) Hydrogenation Reactions and Coupling Reactions by Intercepting Reactive Intermediates Thereof

Synthesis ◽  
2020 ◽  
Vol 52 (17) ◽  
pp. 2483-2496
Author(s):  
Johannes F. Teichert ◽  
Lea T. Brechmann
Keyword(s):  
Coupling Reaction ◽  
Reactive Intermediates ◽  
Transfer Hydrogenation ◽  
Coupling Reactions ◽  
Bond Forming ◽  
Starting Point ◽  
Bond Forming Reactions ◽  
Hydrogenation Reactions ◽  
Multicomponent Coupling Reactions ◽  
Trapping Reactions

The key reactive intermediate of copper(I)-catalyzed alkyne semihydrogenations is a vinylcopper(I) complex. This intermediate can be exploited as a starting point for a variety of trapping reactions. In this manner, an alkyne semihydrogenation can be turned into a dihydrogen­-mediated coupling reaction. Therefore, the development of copper-catalyzed (transfer) hydrogenation reactions is closely intertwined with the corresponding reductive trapping reactions. This short review highlights and conceptualizes the results in this area so far, with H2-mediated carbon–carbon and carbon–heteroatom bond-forming reactions emerging under both a transfer hydrogenation setting as well as with the direct use of H2. In all cases, highly selective catalysts are required that give rise to atom-economic multicomponent coupling reactions with rapidly rising molecular complexity. The coupling reactions are put into perspective by presenting the corresponding (transfer) hydrogenation processes first.1 Introduction: H2-Mediated C–C Bond-Forming Reactions2 Accessing Copper(I) Hydride Complexes as Key Reagents for Coupling Reactions; Requirements for Successful Trapping Reactions 3 Homogeneous Copper-Catalyzed Transfer Hydrogenations4 Trapping of Reactive Intermediates of Alkyne Transfer Semi­hydrogenation Reactions: First Steps Towards Hydrogenative Alkyne Functionalizations 5 Copper(I)-Catalyzed Alkyne Semihydrogenations6 Copper(I)-Catalyzed H2-Mediated Alkyne Functionalizations; Trapping of Reactive Intermediates from Catalytic Hydrogenations6.1 A Detour: Copper(I)-Catalyzed Allylic Reductions, Catalytic Generation of Hydride Nucleophiles from H2 6.2 Trapping with Allylic Electrophiles: A Copper(I)-Catalyzed Hydro­allylation Reaction of Alkynes 6.3 Trapping with Aryl Iodides7 Conclusion

Carbon Dioxide as a Carbon Resource – Recent Trends and Perspectives

2012 ◽  
Vol 67 (10) ◽  
pp. 961-975 ◽  
Author(s):  
Markus Hölscher ◽  
Christoph Gürtler ◽  
Wilhelm Keim ◽  
Thomas E. Müller ◽  
Martina Peters ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Raw Materials ◽  
Low Cost ◽  
Polymeric Materials ◽  
Short Review ◽  
Chemical Research ◽  
Bond Forming ◽  
Bulk Chemicals ◽  
High Thermodynamic Stability ◽  
Recent Trends

With the growing perception of industrialized societies that fossil raw materials are limited resources, academic chemical research and chemical industry have started to introduce novel catalytic technologies which aim at the development of economically competitive processes relying much more strongly on the use of alternative carbon feedstocks. Great interest is given world-wide to carbon dioxide (CO2) as it is part of the global carbon cycle, nontoxic, easily available in sufficient quantities anywhere in the industrialized world, and can be managed technically with ease, and at low cost. In principle carbon dioxide can be used to generate a large variety of synthetic products ranging from bulk chemicals like methanol and formic acid, through polymeric materials, to fine chemicals like aromatic acids useful in the pharmaceutical industry. Owing to the high thermodynamic stability of CO2, the energy constraints of chemical reactions have to be carefully analyzed to select promising processes. Furthermore, the high kinetic barriers for incorporation of CO2 into C-H or C-C bond forming reactions require that any novel transformation of CO2 must inevitably be associated with a novel catalytic technology. This short review comprises a selection of the most recent academic and industrial research developments mainly with regard to innovations in CO2 chemistry in the field of homogeneous catalysis and processes.

Recent Advances in the Incorporation of CO2 for C-H and C-C bond Functionalization

2021 ◽  
Author(s):  
Sandeep Pimparkar ◽  
Aishwarya K. Dalvi ◽  
Adithyaraj Koodan ◽  
Siddhartha Maiti ◽  
Shaeel Al-Thabaiti ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Carbon Dioxide ◽  
Thermodynamic Stability ◽  
Cost Effective ◽  
Bond Functionalization ◽  
Synthetic Organic Chemistry ◽  
Recent Advances ◽  
Carbon Dioxide Co2

Carbon dioxide (CO2) has emerged as one of the exciting cost-effective, abundant, and ready-to-use C1 sources in synthetic organic chemistry. However, the thermodynamic stability, as well as the kinetic inertness,...

scholarly journals Cellulose recycling as a source of raw chirality

2013 ◽  
Vol 85 (8) ◽  
pp. 1683-1692 ◽  
Author(s):  
Valeria Corne ◽  
María Celeste Botta ◽  
Enrique D. V. Giordano ◽  
Germán F. Giri ◽  
David F. Llompart ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Organic Carbon ◽  
Asymmetric Synthesis ◽  
Building Blocks ◽  
Biologically Active ◽  
Raw Material ◽  
Chiral Auxiliaries ◽  
High Chemical ◽  
Chiral Structure

Modern organic chemistry requires easily obtainable chiral building blocks that show high chemical versatility for their application in the synthesis of enantiopure compounds. Biomass has been demonstrated to be a widely available raw material that represents the only abundant source of renewable organic carbon. Through the pyrolitic conversion of cellulose or cellulose-containing materials it is possible to produce levoglucosenone, a highly functionalized chiral structure. This compound has been innovatively used as a template for the synthesis of key intermediates of biologically active products and for the preparation of chiral auxiliaries, catalysts, and organocatalysts for their application in asymmetric synthesis.

Sign in / Sign up

Export Citation Format

Share Document