Recent Advances in C–H Functionalisation through Indirect Hydrogen Atom Transfer DOI Creative Commons
Filip S. Meger, John A. Murphy

Molecules, Journal Year: 2023, Volume and Issue: 28(16), P. 6127 - 6127

Published: Aug. 18, 2023

The functionalisation of C–H bonds has been an enormous achievement in synthetic methodology, enabling new retrosynthetic disconnections and affording simple equivalents for synthons. Hydrogen atom transfer (HAT) is a key method forming alkyl radicals from substrates. Classic reactions, including the Barton nitrite ester reaction Hofmann–Löffler–Freytag reaction, among others, provided early examples HAT. However, recent developments photoredox catalysis electrochemistry have made HAT powerful tool capable introducing wide range functional groups into bonds. Moreover, greater mechanistic insights stimulated development increasingly site-selective protocols. Site-selectivity can be achieved through tuning electron density at certain using additives, judicious choice reagent, solvent system. Herein, we describe latest methods functionalizing C–H/Si–H/Ge–H indirect between 2018–2023, as well critical discussion reagents, aspects, substrate scopes, background contexts

Language: Английский

Visible-light photocatalytic di- and hydro-carboxylation of unactivated alkenes with CO2 DOI
Lei Song, Wei Wang, Jun‐Ping Yue

et al.

Nature Catalysis, Journal Year: 2022, Volume and Issue: 5(9), P. 832 - 838

Published: Sept. 15, 2022

Language: Английский

Citations

153
Photocatalytic defluoroalkylation and hydrodefluorination of trifluoromethyls using o-phosphinophenolate DOI Creative Commons
Can Liu,

Ni Shen,

Rui Shang

et al.

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Jan. 17, 2022

Under visible light irradiation, o-phosphinophenolate functions as an easily accessible photoredox catalyst to activate trifluoromethyl groups in trifluoroacetamides, trifluoroacetates, and (hetero)arenes deliver corresponding difluoromethyl radicals. It works relay with a thiol hydrogen atom transfer (HAT) enable selective defluoroalkylation hydrodefluorination. The reaction allows for the facile synthesis of broad scope difluoromethylene-incorporated carbonyl (hetero)aromatic compounds, which are valuable fluorinated intermediates interest pharmaceutical industry. ortho-diphenylphosphino substituent, is believed facilitate photoinduced electron transfer, plays essential role redox reactivity phenolate. In addition groups, pentafluoroethyl could also be selectively defluoroalkylated.

Language: Английский

Citations

106
Size Effects of Highly Dispersed Bismuth Nanoparticles on Electrocatalytic Reduction of Carbon Dioxide to Formic Acid DOI Creative Commons
Guangri Jia, Ying Wang, Mingzi Sun

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(25), P. 14133 - 14142

Published: June 15, 2023

Electrocatalytic reduction of carbon dioxide into value-added chemical fuels is a promising way to achieve neutrality. Bismuth-based materials have been considered as favorable electrocatalysts for converting formic acid. Moreover, size-dependent catalysis offers significant advantages in catalyzed heterogeneous processes. However, the size effects bismuth nanoparticles on acid production not fully explored. Here, we prepared Bi uniformly supported porous TiO2 substrate electrocatalytic by situ segregation element from Bi4Ti3O12. The Bi-TiO2 electrocatalyst with 2.83 nm displays Faradaic efficiency greater than 90% over wide potential range 400 mV. Theoretical calculations also demonstrated subtle electronic structural evolutions induced variations nanoparticles, where display most active p-band and d-band centers guarantee high electroactivity toward CO2RR.

Language: Английский

Citations

100
Red Light-Based Dual Photoredox Strategy Resembling the Z-Scheme of Natural Photosynthesis DOI Creative Commons
Felix Glaser, Oliver S. Wenger

JACS Au, Journal Year: 2022, Volume and Issue: 2(6), P. 1488 - 1503

Published: June 10, 2022

Photoredox catalysis typically relies on the use of single chromophores, whereas strategies, in which two different light absorbers are combined, rare. In photosystems I and II green plants, separate chromophores P680 P700 both absorb independently one another, then their excitation energy is combined so-called Z-scheme, to drive an overall reaction that thermodynamically very demanding. Here, we adapt this concept perform photoredox reactions organic substrates with input red photons instead blue or UV light. Specifically, a CuI bis(α-diimine) complex combination situ formed 9,10-dicyanoanthracenyl radical anion presence excess diisopropylethylamine catalyzes ca. 50 dehalogenation detosylation reactions. This dual approach seems useful because less damaging has greater penetration depth than radiation. UV-vis transient absorption spectroscopy reveals subtle change solvent from acetonitrile acetone induces changeover mechanism, involving either dominant photoinduced electron transfer triplet-triplet pathway. Our study illustrates mechanistic complexity systems operating under multiphotonic conditions, it provides insights into how competition between desirable unwanted steps can become more controllable.

Language: Английский

Citations

74
Dicarboxylation of Alkenes with CO2 and Formate via Photoredox Catalysis DOI
Pei Xu, Sai Wang, Hui Xu

et al.

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(3), P. 2149 - 2155

Published: Jan. 25, 2023

Herein, a photocatalytic strategy for the synthesis of succinic acids by alkene dicarboxylation with carbon dioxide (CO2) and formate salt as synergistic sources is described. The acts both C1 source reductant in reaction catalytic amount 1,4-diazabicyclo[2.2.2]octane (DABCO) hydrogen atom transfer reagent. Various mono-, di-, trisubstituted alkenes, acrylate, acrylamide, indole derivatives could be converted to corresponding diacids, which provided potential useful applications medicinal chemistry polymer industry.

Language: Английский

Citations

62
Radical Hydrocarboxylation of Unactivated Alkenes via Photocatalytic Formate Activation DOI
Sara N. Alektiar, Jimin Han, Yun Dang

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(20), P. 10991 - 10997

Published: May 15, 2023

Herein we disclose a strategy to promote the hydrocarboxylation of unactivated alkenes using photochemical activation formate salts. We illustrate that an alternative initiation mechanism circumvents limitations prior approaches and enables this challenging substrate class. Specifically, found accessing requisite thiyl radical initiator without exogenous chromophore eliminates major byproducts have plagued attempts exploit similar reactivity for alkene substrates. This redox-neutral method is technically simple execute effective across broad range Feedstock alkenes, such as ethylene, are hydrocarboxylated at ambient temperature pressure. A series cyclization experiments indicate how described in report can be diverted by more complex processes.

Language: Английский

Citations

62
Electroreductive Dicarboxylation of Unactivated Skipped Dienes with CO2 DOI
Wei Zhang, Li‐Li Liao, Li Li

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(23)

Published: April 3, 2023

Carboxylation of easily available alkenes with CO2 is highly important to afford value-added carboxylic acids. Although dicarboxylation activated alkenes, especially 1,3-dienes, has been widely investigated, the challenging unactivated 1,n-dienes (n>3) remains unexplored. Herein, we report first skipped dienes via electrochemistry, affording valuable dicarboxylic Control experiments and DFT calculations support single electron transfer (SET) reduction its radical anion, which followed by sluggish addition SET unstabilized alkyl radicals carbanions nucleophilic attack on give desired products. This reaction features mild conditions, broad substrate scope, facile derivations products promising application in polymer chemistry.

Language: Английский

Citations

61
Recent Advances in Reactions Involving Carbon Dioxide Radical Anion DOI
Wei Xiao, Jun Zhang, Jie Wu

et al.

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(24), P. 15991 - 16011

Published: Nov. 28, 2023

Carbon dioxide radical anion (CO2•–) is a highly reactive nucleophilic species that has recently emerged in organic chemistry as strong single electron donor (reductant) and reactant for the synthesis of carboxylic acids. In general, CO2•– can be generated by either direct reduction CO2 or HAT formate salts. Achievements reactions involving have been witnessed recent years. This Review summarizes advances highlighting some challenges identifying potential areas improvement, which may offer inspiration future studies.

Language: Английский

Citations

55
Metallaphotoredox-enabled aminocarboxylation of alkenes with CO2 DOI
Jun‐Ping Yue,

Jincheng Xu,

Hai‐Tian Luo

et al.

Nature Catalysis, Journal Year: 2023, Volume and Issue: 6(10), P. 959 - 968

Published: Sept. 21, 2023

Language: Английский

Citations

54
Arylcarboxylation of unactivated alkenes with CO2 via visible-light photoredox catalysis DOI Creative Commons
Wei Zhang, Zhen Chen, Yuan‐Xu Jiang

et al.

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: June 14, 2023

Photocatalytic carboxylation of alkenes with CO2 is a promising and sustainable strategy to synthesize high value-added carboxylic acids. However, it challenging rarely investigated for unactivated due their low reactivities. Herein, we report visible-light photoredox-catalyzed arylcarboxylation CO2, delivering variety tetrahydronaphthalen-1-ylacetic acids, indan-1-ylacetic indolin-3-ylacetic chroman-4-ylacetic acids thiochroman-4-ylacetic in moderate-to-good yields. This reaction features chemo- regio-selectivities, mild conditions (1 atm, room temperature), broad substrate scope, good functional group compatibility, easy scalability facile derivatization products. Mechanistic studies indicate that situ generation carbon dioxide radical anion following addition might be involved the process.

Language: Английский

Citations

51