Pd-Catalyzed Functionalization of Aryl Amines on a Soluble Polymer Support

AbstractHerein we report the use of a soluble polymer support PEG-2000 on Pd-catalyzed reactions to improve the functionalization of aromatic amines and the synthesis of N-heterocycles. Compatibility of metal-catalyzed reactions for assembling privileged structures such as functionalized anilines were studied. PEG-supported anilines were found to be suitable substrates for Pd-catalyzed N-arylation, Sonogashira and Heck reactions. PEGylated substrates were prepared in yields up to 94%. This work consists on a proof of concept on the use of PEGylated anilines on Pd-catalyzed cross-coupling reactions. Indole core was attained in 82% and 62% yields, via two different routes.

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The Role of PEG on Pd- and Cu-Catalyzed Cross-Coupling Reactions

Synthesis ◽

10.1055/s-0036-1589498 ◽

2017 ◽

Vol 49 (11) ◽

pp. 2337-2350 ◽

Cited By ~ 12

Author(s):

Marina Pires ◽

Sara Purificação ◽

A. Santos ◽

M. Marques

Keyword(s):

Phase Transfer ◽

Cross Coupling ◽

Polymer Support ◽

Coupling Reactions ◽

Heck Reactions ◽

Cross Coupling Reactions ◽

Direct Formation ◽

Metal Catalyzed ◽

Sonogashira Reactions

Carbon–carbon and carbon–heteroatom coupling reactions are among the most important transformations in organic synthesis as they enable complex structures to be formed from readily available compounds under different routes and conditions. Several metal-catalyzed cross-coupling reactions have been developed creating many efficient methods accessible for the direct formation of new bonds between differently hybridized carbon atoms.During the last decade, much effort has been devoted towards improvement of the sustainability of these reactions, such as catalyst recovery and atom efficiency. Polyethylene glycol (PEG) can be used as a medium, as solid-liquid phase transfer catalyst, or even as a polymer support. PEG has been investigated in a wide variety of cross-coupling reactions either as an alternative solvent to the common organic solvents or as a support for catalyst, substrate, and ligand. In this review we will summarize the different roles of PEG in palladium- and copper-catalyzed cross-coupling reactions, with the focus on Heck, Suzuki–Miyaura, Sonogashira, Buchwald–Hartwig, Stille, Fukuyama, and homocoupling reactions. We will highlight the role of PEG, the preparation of PEGylated catalysts and substrates, and the importance for the reaction outcome and applicability.1 Introduction2 PEG in Heck Reactions3 PEG in Homocoupling Reactions4 PEG in Suzuki–Miyaura Reactions5 PEG in Sonogashira Reactions6 PEG in Buchwald–Hartwig Reactions7 PEG in Stille Reactions8 PEG in Fukuyama Reactions9 PEG in Miscellaneous Cross-Coupling Routes10 Conclusions

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Monodentate Trialkylphosphines: Privileged Ligands in Metal-catalyzed Crosscoupling Reactions

Current Organic Chemistry ◽

10.2174/1385272824666200211114540 ◽

2020 ◽

Vol 24 (3) ◽

pp. 231-264 ◽

Cited By ~ 3

Author(s):

Kevin H. Shaughnessy

Keyword(s):

Transition Metal ◽

Cross Coupling ◽

Coupling Reactions ◽

Cross Coupling Reactions ◽

Aryl Bromides ◽

Wide Range ◽

Sterically Demanding ◽

Transition Metal Catalyzed ◽

Catalyzed Reactions ◽

Metal Catalyzed

Phosphines are widely used ligands in transition metal-catalyzed reactions. Arylphosphines, such as triphenylphosphine, were among the first phosphines to show broad utility in catalysis. Beginning in the late 1990s, sterically demanding and electronrich trialkylphosphines began to receive attention as supporting ligands. These ligands were found to be particularly effective at promoting oxidative addition in cross-coupling of aryl halides. With electron-rich, sterically demanding ligands, such as tri-tertbutylphosphine, coupling of aryl bromides could be achieved at room temperature. More importantly, the less reactive, but more broadly available, aryl chlorides became accessible substrates. Tri-tert-butylphosphine has become a privileged ligand that has found application in a wide range of late transition-metal catalyzed coupling reactions. This success has led to the use of numerous monodentate trialkylphosphines in cross-coupling reactions. This review will discuss the general properties and features of monodentate trialkylphosphines and their application in cross-coupling reactions of C–X and C–H bonds.

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Copper’s rapid ascent in visible-light photoredox catalysis

Science ◽

10.1126/science.aav9713 ◽

2019 ◽

Vol 364 (6439) ◽

pp. eaav9713 ◽

Cited By ~ 107

Author(s):

Asik Hossain ◽

Aditya Bhattacharyya ◽

Oliver Reiser

Keyword(s):

Visible Light ◽

Organic Dyes ◽

Low Cost ◽

Cross Coupling ◽

Coupling Reactions ◽

Photoredox Catalysis ◽

Cross Coupling Reactions ◽

Rapid Ascent ◽

Catalyzed Reactions ◽

Metal Catalyzed

Visible-light photoredox catalysis offers a distinct activation mode complementary to thermal transition metal catalyzed reactions. The vast majority of photoredox processes capitalizes on precious metal ruthenium(II) or iridium(III) complexes that serve as single-electron reductants or oxidants in their photoexcited states. As a low-cost alternative, organic dyes are also frequently used but in general suffer from lower photostability. Copper-based photocatalysts are rapidly emerging, offering not only economic and ecological advantages but also otherwise inaccessible inner-sphere mechanisms, which have been successfully applied to challenging transformations. Moreover, the combination of conventional photocatalysts with copper(I) or copper(II) salts has emerged as an efficient dual catalytic system for cross-coupling reactions.

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Transition-metal-catalyzed reactions of carbon-heteroatom bond formation by substitution and addition processes

Pure and Applied Chemistry ◽

10.1351/pac200577122021 ◽

2005 ◽

Vol 77 (12) ◽

pp. 2021-2027 ◽

Cited By ~ 21

Author(s):

Irina P. Beletskaya

Keyword(s):

Transition Metal ◽

Triple Bond ◽

Bond Formation ◽

Cross Coupling ◽

Addition Reactions ◽

Coupling Reactions ◽

Cross Coupling Reactions ◽

Transition Metal Catalyzed ◽

Catalyzed Reactions ◽

Metal Catalyzed

Two types of transition-metal-catalyzed cross-coupling reactions, which both lead to the formation of carbon-heteroatom bonds, are considered: RX + E-H and E-X + RM. The potential of addition reactions of E-H or E-E to double or triple bond in C-E bond formation is also demonstrated.

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Dimethylisosorbide (DMI) as a Bio-Derived Solvent for Pd-Catalyzed Cross-Coupling Reactions

Synlett ◽

10.1055/s-0037-1611054 ◽

2018 ◽

Vol 29 (17) ◽

pp. 2293-2297 ◽

Cited By ~ 6

Author(s):

Allan Watson ◽

Kirsty Wilson ◽

Jane Murray ◽

Helen Sneddon ◽

Craig Jamieson

Keyword(s):

Chemical Industry ◽

Cross Coupling ◽

Coupling Reactions ◽

Heck Reactions ◽

Bond Forming ◽

Cross Coupling Reactions ◽

Bond Forming Reactions ◽

Palladium Catalyzed ◽

Catalyzed Reactions

Palladium-catalyzed bond-forming reactions, such as the Suzuki–Miyaura and Mizoroki–Heck reactions, are some of the most broadly utilized reactions within the chemical industry. These reactions frequently employ hazardous solvents; however, to adhere to increasing sustainability pressures and restrictions regarding the use of such solvents, alternatives are highly sought after. Here we demonstrate the utility of dimethyl isosorbide (DMI) as a bio-derived solvent in several benchmark Pd-catalyzed reactions: Suzuki–Miyaura (13 examples, 62–100% yield), Mizoroki–Heck (13 examples, 47–91% yield), and Sonogashira (12 examples, 65–98% yield).

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Aryl-Decarboxylation Reactions Catalyzed by Palladium: Scope and Mechanism

Synthesis ◽

10.1055/s-0039-1690769 ◽

2019 ◽

Vol 52 (03) ◽

pp. 365-377 ◽

Cited By ~ 4

Author(s):

Ryan A. Daley ◽

Joseph J. Topczewski

Keyword(s):

Carboxylic Acids ◽

Boronic Acid ◽

Cross Coupling ◽

Coupling Reactions ◽

Heck Reactions ◽

Cross Coupling Reactions ◽

Related Family ◽

Organometallic Precursor ◽

Palladium Catalyzed ◽

Catalyzed Reactions

Palladium-catalyzed cross-couplings and related reactions have enabled many transformations essential to the synthesis of pharmaceuticals, agrochemicals, and organic materials. A related family of reactions that have received less attention are decarboxylative functionalization reactions. These reactions replace the preformed organometallic precursor (e.g., boronic acid or organostannane) with inexpensive and readily available carboxylic acids for many palladium-catalyzed reactions. This review focuses on catalyzed reactions where the elementary decarboxylation step is thought to occur at a palladium center. This review does not include decarboxylative reactions where decarboxylation is thought to be facilitated by a second metal (copper or silver) and is specifically limited to (hetero)arenecarboxylic acids. This review includes a discussion of oxidative Heck reactions, protodecarboxylation reactions, and cross-coupling reactions among others.1 Introduction2 Oxidative Heck Reactions3 Protodecarboxylation Reactions4 Cross-Coupling Reactions5 Other Reactions6 Conclusion

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Metal-Catalyzed Cross-Coupling Reactions on Azaindole Synthesis and Functionalization

Molecules ◽

10.3390/molecules23102673 ◽

2018 ◽

Vol 23 (10) ◽

pp. 2673 ◽

Cited By ~ 14

Author(s):

A. Santos ◽

Ana Mortinho ◽

M. Marques

Keyword(s):

Drug Discovery ◽

Scientific Community ◽

Cross Coupling ◽

Coupling Reactions ◽

Cross Coupling Reactions ◽

Synthetic Methodologies ◽

Catalyzed Reactions ◽

Metal Catalyzed

Azaindoles are rare in nature but extremely attractive for drug discovery programs. Azaindoles can be obtained by diverse methods, including those involving metal-catalyzed reactions. This important core has been fascinating the scientific community due to their challenging synthesis and relevant bioactivity. This paper highlights the diverse synthetic methodologies developed to date involving metal-catalyzed reaction to attain azaindoles and its functionalization.

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Ring Rearrangement Metathesis in 7-Oxabicyclo[2.2.1]heptene (7-Oxanorbornene) Derivatives. Some Applications in Natural Product Chemistry

Natural Product Communications ◽

10.1177/1934578x1701200517 ◽

2017 ◽

Vol 12 (5) ◽

pp. 1934578X1701200

Author(s):

Silvia Roscales ◽

Joaquín Plumet

Keyword(s):

Diels Alder ◽

Coupling Reactions ◽

Alkyne Metathesis ◽

Heck Reactions ◽

One Pot ◽

Cross Metathesis ◽

Cross Coupling Reactions ◽

Synthetic Procedure ◽

Metathesis Reactions ◽

Metal Catalyzed

Metathesis reactions is firmly established as a valuable synthetic tool in organic chemistry, clearly comparable with the venerable Diels-Alder and Wittig reactions and, more recently, with the metal-catalyzed cross-coupling reactions. Metathesis reactions can be considered as a fascinating synthetic methodology, allowing different variants regarding substrate (alkene and alkyne metathesis) and type of metathetical reactions. On the other hand, tandem metathesis reactions such Ring Rearrangement Metathesis (RRM) and the coupling of metathesis reaction with other reactions of alkenes such as Diels-Alder or Heck reactions, makes metathesis one of the most powerful and reliable synthetic procedure. In particular, Ring-Rearrangement Metathesis (RRM) refers to the combination of several metathesis transformations into a domino process such as ring-opening metathesis (ROM)/ring-closing metathesis (RCM) and ROM-cross metathesis (CM) in a one-pot operation. RRM delivers complex frameworks that are difficult to assemble by conventional methods constitutingan atom economic process. RRM is applicable to mono- and polycyclic systems of varying ring sizes such as cyclopropene, cyclobutene, cyclopentene, cyclohexene, pyran systems, bicyclo[2.2.1]heptene derivatives, bicyclo[2.2.2]octene derivatives, bicyclo[3.2.1]octene derivatives and bicyclo[3.2.1]octene derivatives. In this review our attention has focused on the RRM reactions in 7-oxabicyclo[2.2.1]heptene derivatives and on their application in the synthesis of natural products or significant subunits of them.

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Recent Advances in the Synthesis of Benzimidazole Derivatives from the Oxidative Coupling of Primary Amines

Synthesis ◽

10.1055/s-0036-1590915 ◽

2017 ◽

Vol 50 (02) ◽

pp. 241-253 ◽

Cited By ~ 18

Author(s):

Martine Largeron ◽

Khac Nguyen

Keyword(s):

Oxidative Coupling ◽

Environmentally Benign ◽

Primary Amines ◽

Benzimidazole Derivatives ◽

Coupling Reactions ◽

Cross Coupling Reactions ◽

Different Types ◽

Catalyzed Reactions ◽

Metal Catalyzed ◽

Molecular Framework

Benzimidazole belongs to the top five most commonly used five-membered aromatic nitrogen heterocycles among U.S. FDA approved pharmaceuticals. Over the last few years, a large number of improved synthetic strategies have been developed to construct the benzimidazole molecular framework under environmentally benign conditions. This review focuses on the use of primary amines as readily available substrates for the synthesis of benzimidazole derivatives through different types of oxidative cross-coupling reactions.1 Introduction2 Catalyst-Free Oxidative Coupling of Primary Amines3 Catalytic Oxidative Coupling of Primary Amines3.1 Metal-Catalyzed Reactions3.2 Metal-Free Catalyzed Reactions3.3 Bioinspired Catalyzed Reactions4 Conclusion

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