Radical Carbonyl Umpolung Arylation via Dual Nickel Catalysis DOI
Huan‐Ming Huang, Peter Bellotti, Johannes E. Erchinger

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(4), P. 1899 - 1909

Published: Jan. 18, 2022

The formation of carbon-carbon bonds lies at the heart synthetic organic chemistry and is widely applied to construct complex drugs, polymers, materials. Despite its importance, catalytic carbonyl arylation remains comparatively underdeveloped, due limited scope functional group tolerance. Herein we disclose an umpolung strategy achieve radical via dual catalysis. This redox-neutral approach provides a complementary method Grignard-type products from (hetero)aryl bromides aliphatic aldehydes, without need for pre-functionalization. A sequential activation, hydrogen-atom transfer, halogen atom transfer process could directly convert aldehydes corresponding ketyl-type radicals, which further react with aryl-nickel intermediates in overall polarity-reversal process. tolerates─among others─acidic groups, heteroaryl motifs, sterically hindered substrates has been late-stage modification drugs natural products.

Language: Английский

Photocatalytic Late-Stage C–H Functionalization DOI
Peter Bellotti, Huan‐Ming Huang,

Teresa Faber

et al.

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(8), P. 4237 - 4352

Published: Jan. 24, 2023

The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C–H functionalization approaches that make use low energy photons as a controllable source. Compared to traditional strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- chemoselectivities. Merging compelling benefits with workflow offers potentially unmatched arsenal tackle drug development campaigns beyond. This Review highlights photocatalytic strategies small-molecule drugs, agrochemicals, natural products, classified according targeted bond newly formed one. Emphasis is devoted identifying, describing, comparing main mechanistic scenarios. draws critical comparison between established ionic chemistry photocatalyzed radical-based manifolds. aims establish current state-of-the-art illustrate key unsolved challenges be addressed in future. authors aim introduce general readership functionalization, specialist practitioners evaluation methodologies, potential for improvement, future uncharted directions.

Language: Английский

Citations

322
Supramolecular Coordination Cages for Artificial Photosynthesis and Synthetic Photocatalysis DOI Creative Commons
Rens Ham, C. Jasslie Nielsen,

Sonja Pullen

et al.

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(9), P. 5225 - 5261

Published: Jan. 20, 2023

Because sunlight is the most abundant energy source on earth, it has huge potential for practical applications ranging from sustainable supply to light driven chemistry. From a chemical perspective, excited states generated by make thermodynamically uphill reactions possible, which forms basis storage into fuels. In addition, with light, open-shell species can be open up new reaction pathways in organic synthesis. Crucial are photosensitizers, absorb and transfer substrates various mechanisms, processes that highly depend distance between molecules involved. Supramolecular coordination cages well studied synthetically accessible vessels single cavities guest binding, ensuring close proximity of different components. Due high modularity their size, shape, nature metal centers ligands, ideal platforms exploit preorganization photocatalysis. Herein we focus application supramolecular photocatalysis artificial photosynthesis photo(redox) catalysis. Finally, brief overview immobilization strategies provides tools implementing devices. This review inspiration future design photocatalytic host-guest systems producing solar fuels complex molecules.

Language: Английский

Citations

166
Dearomative ring expansion of thiophenes by bicyclobutane insertion DOI
Huamin Wang, Huiling Shao, Ankita Das

et al.

Science, Journal Year: 2023, Volume and Issue: 381(6653), P. 75 - 81

Published: July 6, 2023

Skeletal ring enlargement is gaining renewed interest in synthetic chemistry and has recently focused on insertion of one or two atoms. Strategies for heterocyclic expansion through small-ring remain elusive, although they would lead to the efficient formation bicyclic products. Here, we report a photoinduced dearomative thiophenes by bicyclo[1.1.0]butanes produce eight-membered rings under mild conditions. The value, broad functional-group compatibility, excellent chemo- regioselectivity were demonstrated scope evaluation product derivatization. Experimental computational studies point toward photoredox-induced radical pathway.

Language: Английский

Citations

115
Difluoromethylation of Unactivated Alkenes Using Freon-22 through Tertiary Amine-Borane-Triggered Halogen Atom Transfer DOI
Zhi‐Qi Zhang,

Yue‐Qian Sang,

Cheng‐Qiang Wang

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(31), P. 14288 - 14296

Published: July 27, 2022

The application of abundant and inexpensive fluorine feedstock sources to synthesize fluorinated compounds is an appealing yet underexplored strategy. Here, we report a photocatalytic radical hydrodifluoromethylation unactivated alkenes with industrial chemical, chlorodifluoromethane (ClCF2H, Freon-22). This protocol realized by merging tertiary amine-ligated boryl radical-induced halogen atom transfer (XAT) organophotoredox catalysis under blue light irradiation. A broad scope readily accessible featuring variety functional groups drug natural product moieties could be selectively difluoromethylated good efficiency in metal-free manner. Combined experimental computational studies suggest that the key XAT process ClCF2H both thermodynamically kinetically favored over hydrogen pathway owing formation strong boron–chlorine (B–Cl) bond low-lying antibonding orbital carbon–chlorine (C–Cl) bond.

Language: Английский

Citations

97
The interplay of polar effects in controlling the selectivity of radical reactions DOI
Alessandro Ruffoni, Rory C. Mykura, Massimo Bietti

et al.

Nature Synthesis, Journal Year: 2022, Volume and Issue: 1(9), P. 682 - 695

Published: Aug. 1, 2022

Language: Английский

Citations

96
Halogen-atom and group transfer reactivity enabled by hydrogen tunneling DOI
Timothée Constantin, Bartosz Górski, Michael J. Tilby

et al.

Science, Journal Year: 2022, Volume and Issue: 377(6612), P. 1323 - 1328

Published: Sept. 15, 2022

The generation of carbon radicals by halogen-atom and group transfer reactions is generally achieved using tin silicon reagents that maximize the interplay enthalpic (thermodynamic) polar (kinetic) effects. In this work, we demonstrate a distinct reactivity mode enabled quantum mechanical tunneling uses cyclohexadiene derivative γ-terpinene as abstractor under mild photochemical conditions. This protocol activates alkyl aryl halides well several alcohol thiol derivatives. Experimental computational studies unveiled noncanonical pathway whereby cyclohexadienyl radical undergoes concerted aromatization or abstraction through an effective H atom. activation mechanism seemingly thermodynamically kinetically unfavorable but rendered feasible tunneling.

Language: Английский

Citations

89
Radical and ionic meta -C–H functionalization of pyridines, quinolines, and isoquinolines DOI
Hui Cao, Qiang Cheng, Armido Studer

et al.

Science, Journal Year: 2022, Volume and Issue: 378(6621), P. 779 - 785

Published: Nov. 17, 2022

Carbon-hydrogen (C−H) functionalization of pyridines is a powerful tool for the rapid construction and derivatization many agrochemicals, pharmaceuticals, materials. Because inherent electronic properties pyridines, selective meta -C−H challenging. Here, we present protocol highly regioselective trifluoromethylation, perfluoroalkylation, chlorination, bromination, iodination, nitration, sulfanylation, selenylation through redox-neutral dearomatization-rearomatization process. The introduced dearomative activation mode provides diversification platform meta-selective reactions on other azaarenes radical as well ionic pathways. broad scope high selectivity these catalyst-free render processes applicable late-stage drugs.

Language: Английский

Citations

80
Photocatalytic C(sp3) radical generationviaC–H, C–C, and C–X bond cleavage DOI Creative Commons
Chia‐Yu Huang, Jianbin Li, Chao‐Jun Li

et al.

Chemical Science, Journal Year: 2022, Volume and Issue: 13(19), P. 5465 - 5504

Published: Jan. 1, 2022

C(sp 3 ) radicals (R˙) are of broad research interest and synthetic utility.

Language: Английский

Citations

75
Photoinduced gold-catalyzed divergent dechloroalkylation of gem-dichloroalkanes DOI
Cheng‐Long Ji, Jie Han,

Tingrui Li

et al.

Nature Catalysis, Journal Year: 2022, Volume and Issue: 5(12), P. 1098 - 1109

Published: Dec. 15, 2022

Language: Английский

Citations

72
Synthetic Applications of Photocatalyzed Halogen‐Radical Mediated Hydrogen Atom Transfer for C−H Bond Functionalization DOI Creative Commons
Stefano Bonciolini, Timothy Noël, Luca Capaldo

et al.

European Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 2022(34)

Published: May 13, 2022

Abstract The opportunity to activate C(sp 3 )−H bonds via homolytic cleavage by means of halogen radicals has long been disregarded in synthetic endeavors due the unpredictable selectivity. Nowadays, photocatalysis established itself as a method choice for generation such reactive intermediates under mild conditions. This Minireview collects recent examples showcasing how photocatalytic manifolds have used tame aggressive Hydrogen Atom Transfer (HAT) purposes. In last section this work, we address site‐selectivity issues posed methodology and show it can be guided through judicious reaction

Language: Английский

Citations

71