Connecting Remote C–H Bond Functionalization and Decarboxylative Coupling Using Simple Amines

2019 ◽  
Author(s):  
Francisco de Azambuja ◽  
Ming-Hsiu Yang ◽  
Alexander Bruecker ◽  
Paul Cheong ◽  
Ryan Altman
Keyword(s):  
Organic Molecules ◽  
Mechanistic Studies ◽  
Bond Functionalization ◽  
Bond Forming ◽  
Decarboxylative Coupling

The manuscript describes a Pd-catalyzed reaction of benzylic electrophiles that gives para-substituted arene products. Mechanistic studies suggest a mechanism involving a dearomative C–C bond-forming step, followed by base-mediated rearomatization. This mechanism is uncommon and underappreciated in Pd-catalysis and further exploitation of this mechanism should enable access to other organic molecules.

Connecting Remote C–H Bond Functionalization and Decarboxylative Coupling Using Simple Amines

2019 ◽  
Author(s):  
Francisco de Azambuja ◽  
Ming-Hsiu Yang ◽  
Alexander Bruecker ◽  
Paul Cheong ◽  
Ryan Altman
Keyword(s):  
Organic Molecules ◽  
Mechanistic Studies ◽  
Bond Functionalization ◽  
Bond Forming ◽  
Decarboxylative Coupling

The manuscript describes a Pd-catalyzed reaction of benzylic electrophiles that gives para-substituted arene products. Mechanistic studies suggest a mechanism involving a dearomative C–C bond-forming step, followed by base-mediated rearomatization. This mechanism is uncommon and underappreciated in Pd-catalysis and further exploitation of this mechanism should enable access to other organic molecules.

C-H bond functionalization using Pd and Au supported catalysts with mechanistic insights of the active species

Synthesis ◽  
2021 ◽  
Author(s):  
Tamao Ishida ◽  
Zhenzhong Zhang ◽  
Haruno Murayama ◽  
Eiji Yamamoto ◽  
Makoto Tokunaga
Keyword(s):  
Aromatic Compounds ◽  
Reaction Mechanisms ◽  
Bond Activation ◽  
Supported Catalysts ◽  
Metal Catalysts ◽  
Active Species ◽  
Supported Metal Catalysts ◽  
Bond Functionalization ◽  
Bond Forming ◽  
Supported Metal

The C–H functionalization has been extensively studied as a direct C–C bond forming reaction with high atomic efficiency. The efforts have also been made on the reaction using supported catalysts, which are superior in terms of catalyst separation from the reaction mixture and reusability. In this review, an overview of the C–H functionalization reactions, especially for Pd and Au supported catalysts will be described. In particular, we discuss reaction mechanisms, active species, leaching, reusability, etc. 1 Introduction 2 Types of supported metal catalysts and their active species 3 Modes of C–H bond activation 4 Oxidative C–H C–H coupling of aryl compounds 5 C–H C–H coupling where one side is aromatic 6 C–H acylation of aromatic compounds and related reactions 7 Conclusion

Mechanistic studies on boron-doped diamond: Oxidation of small organic molecules

2013 ◽  
Vol 110 ◽  
pp. 560-569 ◽  
Author(s):  
Ana Stefanova ◽  
Sevda Ayata ◽  
Achmet Erem ◽  
Siegfried Ernst ◽  
Helmut Baltruschat
Keyword(s):  
Organic Molecules ◽  
Mechanistic Studies ◽  
Boron Doped Diamond ◽  
Small Organic Molecules ◽  
Boron Doped

scholarly journals Cobalt-catalyzed deoxygenative triborylation of allylic ethers to access 1,1,3-triborylalkanes

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Wei Jie Teo ◽  
Xiaoxu Yang ◽  
Yeng Yeng Poon ◽  
Shaozhong Ge
Keyword(s):  
Building Blocks ◽  
Mechanistic Studies ◽  
Deuterium Labeling ◽  
Bond Forming ◽  
Carbon Carbon Bond ◽  
Synthetic Utility ◽  
Reaction Proceeds ◽  
Site Selective ◽  
And Control ◽  
Allylic Ethers

Abstract Polyborylated organic compounds have been emerging as versatile building blocks in chemical synthesis. Here we report a selective cobalt-catalyzed deoxygenative 1,1,3-triborylation reaction of allylic ethers with pinacolborane to prepare 1,1,3-triborylalkane compounds. With naturally abundant and/or synthetic cinnamic methyl ethers as starting materials, we have achieved the synthesis of a variety of 1,1,3-triborylalkanes (25 examples). The synthetic utility of these 1,1,3-triborylalkanes is demonstrated through site-selective allylation, protodeborylation, and consecutive carbon-carbon bond-forming reactions. Mechanistic studies including deuterium-labeling and control experiments suggest that this 1,1,3-triborylation reaction proceeds through initial cobalt-catalyzed deoxygenative borylation of allylic ethers to form allylic boronates followed by cobalt-catalyzed 1,1-diborylation of the resulting allylic boronates.

scholarly journals Polar molecules catalyze CO insertion into metal-alkyl bonds through the displacement of an agostic C-H bond

2019 ◽  
Vol 116 (9) ◽  
pp. 3419-3424
Author(s):  
Tian Zhou ◽  
Santanu Malakar ◽  
Steven L. Webb ◽  
Karsten Krogh-Jespersen ◽  
Alan S. Goldman
Keyword(s):  
Transition Metal Complexes ◽  
Density Functional ◽  
Organic Molecules ◽  
Polar Molecules ◽  
Functional Theory ◽  
Bond Forming ◽  
Co Insertion ◽  
The Subject ◽  
Kinetics Of

The insertion of CO into metal-alkyl bonds is the key C-C bond-forming step in many of the most important organic reactions catalyzed by transition metal complexes. Polar organic molecules (e.g., tetrahydrofuran) have long been known to promote CO insertion reactions, but the mechanism of their action has been the subject of unresolved speculation for over five decades. Comprehensive computational studies [density functional theory (DFT)] on the prototypical system Mn(CO)5(arylmethyl) reveal that the polar molecules do not promote the actual alkyl migration step. Instead, CO insertion (i.e. alkyl migration) occurs rapidly and reversibly to give an acyl complex with a sigma-bound (agostic) C-H bond that is not easily displaced by typical ligands (e.g. phosphines or CO). The agostic C-H bond is displaced much more readily, however, by the polar promoter molecules, even though such species bind only weakly to the metal center and are themselves then easily displaced; the facile kinetics of this process are attributable to a hydrogen bonding-like interaction between the agostic C-H bond and the polar promoter. The role of the promoter is to thereby catalyze isomerization of the agostic product of CO insertion to give an η2-C,O-bound acyl product that is more easily trapped than the agostic species. This ability of such promoters to displace a strongly sigma-bound C-H bond and to subsequently undergo facile displacement themselves is without reported precedent, and could have implications for catalytic reactions beyond carbonylation.

scholarly journals Mechanistic studies on the metal-free decarboxylative coupling reaction for synthesis of propargylamines by NMR

ARKIVOC ◽  
2016 ◽  
Vol 2016 (5) ◽  
pp. 1-12
Author(s):  
Yongjun Lee ◽  
Kyungho Park ◽  
Han-Sung Kim ◽  
Jimin Kim ◽  
Young Ju Lee ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Mechanistic Studies ◽  
Metal Free ◽  
Decarboxylative Coupling

scholarly journals Cu(OTf)2-Mediated Ionizing Cross-Coupling of N(sp) and N(sp2) with Arylboronic Acids

2020 ◽  
Author(s):  
Allan Watson ◽  
Nicola Bell ◽  
Chao Xu ◽  
James Fyfe ◽  
Julien Vantourout ◽  
...  
Keyword(s):  
Late Stage ◽  
Cross Coupling ◽  
Reductive Elimination ◽  
Subsequent Generation ◽  
Mechanistic Studies ◽  
Arylboronic Acids ◽  
Bond Forming ◽  
Drug Synthesis ◽  
C And N ◽  
Metal Catalyzed

Metal-catalyzed C–N cross-coupling generally forms C–N bonds by reductive elimination from metal complexes bearing covalent C- and N-ligands. We have identified a Cu-mediated C–N cross-coupling that uses a dative N-ligand in the bond forming event, which, in contrast to conventional methods, generates reactive cationic products. Mechanistic studies suggest the process operates via transmetalation of an aryl organoboron to a Cu(II) complex bearing neutral N-ligands, such as nitriles or N-heterocycles. Subsequent generation of a putative Cu(III) complex enables the oxidative C–N coupling to take place, delivering nitrilium intermediates and pyridinium products. The reaction is general for a range of N(sp) and N(sp<sup>2</sup>) precursors and can be applied to drug synthesis and late-stage N-arylation, and the limitations in the methodology are mechanistically evidenced.

Microwave-assisted organo-catalyzed C-C and C-X (heteroatom) bond-forming reactions-An overview

2021 ◽  
Vol 08 ◽  
Author(s):  
Kantharaju Kamanna ◽  
Yamanappagouda Amaregouda
Keyword(s):  
Organic Molecules ◽  
Organic Transformations ◽  
Large Area ◽  
High Demand ◽  
Moisture Sensitivity ◽  
Small Organic Molecules ◽  
Bond Forming ◽  
Direct Benefits ◽  
Speed Up ◽  
Chemical Manufacture

: Organocatalysis defines small organic molecules exclusively containing carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorous atom to speed-up the chemical reactions. Researcher demonstrated large area of applications in various organic transformations catalyzed by the organocatalysts, due to their less moisture sensitivity and air, easy abundance, less polluting, not interfere with the final product and inexpensive. This highlights high demand and direct benefits in the pharmaceutical intermediate and fine chemical manufacture compared to other conventional transition metal and enzyme catalysts. This review article intends to compile literature reported application of the microwave accelerated organocatalyzed carbon-carbon and carbon–heteroatom bond formation reactions reported in the literature.

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