Review of electrochemical transition‐metal‐catalyzed C−H functionalization reactions DOI

Sumi Changmai,

Sabera Sultana, Anil K. Saikia

et al.

ChemistrySelect, Journal Year: 2023, Volume and Issue: 8(11)

Published: March 14, 2023

Abstract The combination of organometallic C−H activation and electro‐catalysis has emerged as a potent synthetic technique for various molecular scaffolds since it avoids the use harmful expensive chemical oxidants in stoichiometric amounts. Moreover, pre‐functionalization substrates is not required newer ways to perform metal‐catalyzed reactions are possible. Here, we have discussed eletrochemically driven acyloxylation, acetoxylation, oxygenation, acylation, amination, alkylation, halogenation, olefinations C−H/N−H annulation using transition‐metal‐catalyst such Ru, Rh, Pd, Co, Ni, Ir, Cu, Mn Au by anodic oxidation, followed reductive elimination form corresponding C−O, C−C, C−N C−X (X=Cl, Br, S etc.) bonds. This review covers recent developments transition‐metal‐catalyzed electrochemical from 2007 until 2022.

Language: Английский

Electrochemical Desaturative β‐Acylation of Cyclic N‐Aryl Amines DOI
Tian Feng, Siyi Wang, Yin Liu

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 61(6)

Published: Dec. 8, 2021

Abstract Herein, we disclose a straightforward, robust, and simple route to access β‐substituted desaturated cyclic amines via an electrochemically driven desaturative β‐functionalization of amines. This transformation is based on multiple single‐electron oxidation processes using catalytic amounts ferrocene. The reaction proceeds in the absence stoichiometric electrolyte under mild conditions, affording desired products with high chemo‐ regioselectivity. was tolerant broad range substrates also enables late‐stage β‐C(sp 3 )−H acylation potentially valuable products. Preliminary mechanistic studies voltammetry reveal key role ferrocene as redox mediator reaction.

Language: Английский

Citations

81
Mediator-Enabled Electrocatalysis with Ligandless Copper for Anaerobic Chan–Lam Coupling Reactions DOI

Benjamin R. Walker,

Shuhei Manabe, Andrew T. Brusoe

et al.

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(16), P. 6257 - 6265

Published: April 16, 2021

Simple copper salts serve as catalysts to effect C–X bond-forming reactions in some of the most utilized transformations synthesis, including oxidative coupling aryl boronic acids and amines. However, these Chan–Lam have historically relied on chemical oxidants that limit their applicability beyond small-scale synthesis. Despite success replacing strong with electrochemistry for a variety metal-catalyzed processes, electrooxidative ligandless are plagued by slow electron-transfer kinetics, irreversible plating, competitive substrate oxidation. Herein, we report implementation substoichiometric quantities redox mediators address limitations Cu-catalyzed electrosynthesis. Mechanistic studies reveal multiple roles (i) rapidly oxidizing low-valent Cu intermediates, (ii) stripping metal from cathode regenerate catalyst active Pt surface proton reduction, (iii) providing anodic overcharge protection prevent This strategy is applied aryl-, heteroaryl-, alkylamines arylboronic absence oxidants. Couplings under electrochemical conditions occur higher yields shorter reaction times than conventional air provide complementary reactivity.

Language: Английский

Citations

76
Electrooxidative Rhodium‐Catalyzed [5+2] Annulations via C−H/O−H Activations DOI Creative Commons
Yulei Wang, João C. A. Oliveira, Zhipeng Lin

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(12), P. 6419 - 6424

Published: Jan. 20, 2021

Abstract Electrooxidative annulations involving mild transition metal‐catalyzed C−H activation have emerged as a transformative strategy for the rapid construction of five‐ and six‐membered heterocycles. In contrast, we herein describe first electrochemical [5+2] cycloadditions to assemble valuable seven‐membered benzoxepine skeletons by C−H/O−H activation. The efficient alkyne annulation featured ample substrate scope, using electricity only oxidant. Mechanistic studies provided strong support rhodium(III/I) regime, benzoxepine‐coordinated rhodium(I) sandwich complex catalyst resting state, which was re‐oxidized rhodium(III) anodic oxidation.

Language: Английский

Citations

75
Divergent rhodium-catalyzed electrochemical vinylic C–H annulation of acrylamides with alkynes DOI Creative Commons

Yi‐Kang Xing,

Xinran Chen, Qi‐Liang Yang

et al.

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Feb. 10, 2021

α-Pyridones and α-pyrones are ubiquitous structural motifs found in natural products biologically active small molecules. Here, we report an Rh-catalyzed electrochemical vinylic C-H annulation of acrylamides with alkynes, affording cyclic good to excellent yield. Divergent syntheses α-pyridones imidates accomplished by employing N-phenyl N-tosyl as substrates, respectively. Additionally, regioselectivities achieved when using unsymmetrical alkynes. This process is environmentally benign compared traditional transition metal-catalyzed annulations because it avoids the use stoichiometric metal oxidants. DFT calculations elucidated reaction mechanism origins substituent-controlled chemoselectivity. The sequential activation alkyne insertion under rhodium catalysis leads seven-membered ring vinyl-rhodium intermediate. intermediate undergoes either classic neutral concerted reductive elimination produce α-pyridones, or ionic stepwise pathway imidates.

Language: Английский

Citations

59
Azaruthena(II)‐bicyclo[3.2.0]heptadiene: Key Intermediate for Ruthenaelectro(II/III/I)‐catalyzed Alkyne Annulations DOI Creative Commons
Long Yang,

Ralf Steinbock,

Alexej Scheremetjew

et al.

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(27), P. 11130 - 11135

Published: March 4, 2020

A ruthenium-catalyzed electrochemical dehydrogenative annulation reaction of imidazoles with alkynes has been established, enabling the preparation various bridgehead N-fused [5,6]-bicyclic heteroarenes through regioselective C-H/N-H without chemical metal oxidants. Novel azaruthenabicyclo[3.2.0]heptadienes were fully characterized and identified as key intermediates. Mechanistic studies are suggestive an oxidatively induced reductive elimination pathway within a ruthenium(II/III) regime.

Language: Английский

Citations

69
Ruthenaelectro‐Catalyzed Domino Three‐Component Alkyne Annulation for Expedient Isoquinoline Assembly DOI Creative Commons
Xuefeng Tan, Xiaoyan Hou, Torben Rogge

et al.

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(9), P. 4619 - 4624

Published: Dec. 3, 2020

Abstract The electrochemical three‐component assembly of isoquinolines has been accomplished by ruthenaelectro‐catalyzed C−H/N−H functionalization. robustness the electrocatalysis was reflected an ample substrate scope, efficient electrooxidation, and operationally friendly procedure. isolation key intermediates detailed mechanistic studies, including unprecedented cyclovoltammetric analysis a seven‐membered ruthenacycle, provided support for unusual ruthenium(II/III/I) regime.

Language: Английский

Citations

61
Electrochemically Enabled Intramolecular and Intermolecular Annulations of Alkynes DOI
Kai Sun,

Lei Jia,

Yingjie Liu

et al.

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(18), P. 3709 - 3726

Published: Aug. 13, 2020

Abstract Electrosynthesis is recognized as one of the most powerful and sustainable methods in organic chemistry. Recently, electrochemically enabled annulations carbon‐carbon triple bonds have been successfully achieved, broadened prospects for application emerging method with cyclization alkynes. Thus, herein we outline recent progress made on In addition, an emphasis scope, limitations mechanisms these reactions this review. magnified image

Language: Английский

Citations

52
Electrooxidative Iridium-Catalyzed Regioselective Annulation of Benzoic Acids with Internal Alkynes DOI
Qi‐Liang Yang,

Hong-Wei Jia,

Ying Liu

et al.

Organic Letters, Journal Year: 2021, Volume and Issue: 23(4), P. 1209 - 1215

Published: Feb. 4, 2021

Electrochemically driven, Cp*Ir(III)-catalyzed regioselective annulative couplings of benzoic acids with alkynes have been established herein. The combination iridium catalyst and electricity not only circumvents the need for stoichiometric amount chemical oxidant, but also ensures broad reaction compatibility a wide array sterically electronically diverse substrates. This electrochemical approach represents sustainable strategy as an ideal alternative supplement to oxidative annulations methodology be engaged in synthesis isocoumarin derivatives.

Language: Английский

Citations

42
Electrochemical Syntheses of Polycyclic Aromatic Hydrocarbons (PAHs) DOI Creative Commons
Yulei Wang,

Rong Zhao,

Lutz Ackermann

et al.

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(49)

Published: March 25, 2023

Polycyclic aromatic hydrocarbons (PAHs) have surfaced as increasingly viable components in optoelectronics and material sciences. The development of highly efficient atom-economic tools to prepare PAHs under exceedingly mild conditions constitutes a long-term goal. Traditional syntheses largely relied on multistep approaches or the conventional Scholl reaction. However, reactions are inefficient with electron-deficient substrates, require stoichiometric chemical oxidants, typically occur presence strong acid. In sharp contrast, electrochemistry has gained considerable momentum during past decade an alternative for facile straightforward assembly, generally via electro-oxidative dehydrogenative annulation, releasing molecular hydrogen sole byproduct by evolution This review provides overview recent significant advances field electrochemical various until January 2023.

Language: Английский

Citations

18
Heterocyclic Electrochemistry: Renewable Electricity in the Construction of Heterocycles DOI Creative Commons
Samina Aslam, Najoua Sbei, Sadia Rani

et al.

ACS Omega, Journal Year: 2023, Volume and Issue: 8(7), P. 6175 - 6217

Published: Feb. 1, 2023

Numerous applications in the realm of biological exploration and drug synthesis can be found heterocyclic chemistry, which is a vast subject. Many efforts have been developed to further improve reaction conditions access this interesting family prevent employing hazardous ingredients. In instance, it has stated that green environmentally friendly manufacturing methodologies introduced create N-, S-, O-heterocycles. It appears one most promising methods these types compounds avoiding use stoichiometric amounts oxidizing/reducing species or precious metal catalysts, only catalytic are sufficient, represent an ideal way contributing toward resource economy. Thus, renewable electricity provides clean electrons (oxidant/reductant) initiate cascade via producing reactive intermediates facilitate building new bonds for valuable chemical transformations. Moreover, electrochemical activation using metals as mediators identified more efficient strategy selective functionalization. indirect electrolysis makes potential range practical, less side reactions occur. The latest developments electrolytic O-heterocycles main topic mini review, was documented over last five years.

Language: Английский

Citations

17