scholarly journals Copper’s rapid ascent in visible-light photoredox catalysis

Science ◽  
2019 ◽  
Vol 364 (6439) ◽  
pp. eaav9713 ◽  
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.

Monodentate Trialkylphosphines: Privileged Ligands in Metal-catalyzed Crosscoupling Reactions

2020 ◽  
Vol 24 (3) ◽  
pp. 231-264 ◽  
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.

scholarly journals Gram-Scale Synthesis of the N-Phenyl Phenothiazine Photocatalyst by Benzyne Addition

2021 ◽  
Author(s):  
Erin Welsh ◽  
Katherine Robertson ◽  
Alex Speed
Keyword(s):  
Transition Metal ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

N-phenyl phenothiazine is one of the most reducing photoredox catalysts. Its synthesis commonly requires transition metal catalyzed cross-coupling reactions. Here we show the syntheses of four aryl phenothiazines via a benzyne route, including a multi-gram scale synthesis of N-phenyl phenothiazine. While yields are modest, the simplicity, low cost, and lack of requirement for cross-coupling catalyst in this synthesis will be attractive to users of this photocatalyst.

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

2005 ◽  
Vol 77 (12) ◽  
pp. 2021-2027 ◽  
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.

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

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2673 ◽  
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.

scholarly journals Transition-Metal-Free, Visible-Light-Promoted C–S Cross-Coupling through Intermolecular Charge Transfer

Synlett ◽  
2018 ◽  
Vol 29 (19) ◽  
pp. 2449-2455 ◽  
Author(s):  
Garret Miyake ◽  
Bin Liu ◽  
Chern-Hooi Lim
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Materials Science ◽  
Bond Formation ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Visible Light Driven ◽  
Metal Catalyzed ◽  
Historical Developments

C–S cross-couplings are an important class of reactions ­applied across organic synthesis, materials science, and pharma­ceuticals. Several different methodologies have been developed to achieve this significant transformation. However, currently available synthetic procedures significantly rely on transition metals. This article describes historical developments in the field of transition-metal-catalyzed C–S cross-coupling reactions, the development of a visible-light-driven and catalyst-free approach to C–S bond formation, and future outlooks.

Visible light mediated desilylative C(sp2)–C(sp2) cross-coupling reactions of arylsilanes with aryldiazonium salts under Au(i)/Au(iii) catalysis

2018 ◽  
Vol 54 (52) ◽  
pp. 7223-7226 ◽  
Author(s):  
Indradweep Chakrabarty ◽  
Manjur O. Akram ◽  
Suprakash Biswas ◽  
Nitin T. Patil
Keyword(s):  
Visible Light ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Photoredox Catalysis ◽  
Cross Coupling Reactions

Desilylative C(sp2)–C(sp2) cross-coupling reactions of arylsilanes with aryldiazonium salts under Au(i)/photoredox catalysis have been reported.

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

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