Borane-catalyzed cascade Friedel–Crafts alkylation/[1,5]-hydride transfer/Mannich cyclization to afford tetrahydroquinolines DOI Creative Commons
Beibei Zhang,

Shuo Peng,

Feiyi Wang

et al.

Chemical Science, Journal Year: 2021, Volume and Issue: 13(3), P. 775 - 780

Published: Dec. 20, 2021

An unprecedented redox-neutral annulation reaction of tertiary anilines with electron-deficient alkynes was developed that proceeds through a cascade Friedel-Crafts alkylation/[1,5]-hydride transfer/Mannich cyclization sequence. Under B(C6F5)3 catalysis, range functionalized 1,2,3,4-tetrahydroquinolines were facilely constructed in moderate to good yields exclusive 3,4-anti-stereochemistry. The commercial availability the catalyst and high atom step economy procedure, together metal-free external oxidant-free conditions, make this an attractive method organic synthesis.

Language: Английский

Recent Advances in Employing Catalytic Donors and Acceptors in Electron Donor–Acceptor Complex Photochemistry DOI
Tarannum Tasnim, Mayokun J. Ayodele, Spencer P. Pitre

et al.

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(16), P. 10555 - 10563

Published: July 29, 2022

Electron donor–acceptor (EDA) complexes provide a means to initiate radical reactions under visible light irradiation using substrates that do not absorb individually. Catalytic approaches complex formation are vital for advancing this synthetic strategy as it decouples the complexation and photogeneration of radicals from substrate functionalization, limitation inherent stoichiometric restricts structural diversity. This Synopsis highlights recent developments in EDA photochemistry which either donor or acceptor employed catalytically.

Language: Английский

Citations

85
Tetrachlorophthalimides as Organocatalytic Acceptors for Electron Donor–Acceptor Complex Photoactivation DOI
Wei Zhou, Shuo Wu, Paolo Melchiorre

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(20), P. 8914 - 8919

Published: May 13, 2022

Excitation of photoactive electron donor-acceptor (EDA) complexes is an effective way to generate radicals. Applications in a catalytic regime typically use donors. Herein, we report that readily available electron-poor tetrachlorophthalimides can act as organocatalytic acceptors trigger the formation EDA with variety radical precursors not amenable previous methods. visible light generates carbon radicals under mild conditions. The versatility this complex platform allowed us develop mechanistically distinct reactions, including combination cobalt-based system. Quantum yield measurements established closed cycle operational, which hints at ability turn over and govern each cycle.

Language: Английский

Citations

72
Regioselective aliphatic C–H functionalization using frustrated radical pairs DOI
Zhipeng Lu, Minsoo Ju, Yi Wang

et al.

Nature, Journal Year: 2023, Volume and Issue: 619(7970), P. 514 - 520

Published: July 5, 2023

Language: Английский

Citations

68
Insights into Single-Electron-Transfer Processes in Frustrated Lewis Pair Chemistry and Related Donor–Acceptor Systems in Main Group Chemistry DOI Creative Commons
Lars J. C. van der Zee,

Sanjukta Pahar,

Emma Richards

et al.

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(15), P. 9653 - 9675

Published: July 11, 2023

The activation and utilization of substrates mediated by Frustrated Lewis Pairs (FLPs) was initially believed to occur solely via a two-electron, cooperative mechanism. More recently, the occurrence single-electron transfer (SET) from base acid observed, indicating that mechanisms proceed one-electron-transfer processes are also feasible. As such, SET in FLP systems leads formation radical ion pairs, which have recently been more frequently observed. In this review, we aim discuss seminal findings regarding established insights into chemistry as well highlight examples process. addition, applications reported main group radicals will be reviewed discussed context understanding systems.

Language: Английский

Citations

46
Characterization of A π–π stacking cocrystal of 4-nitrophthalonitrile directed toward application in photocatalysis DOI Creative Commons
Ting Xue, Cheng Ma, Le Liu

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Feb. 16, 2024

Abstract Photoexcitation of the electron-donor-acceptor complexes have been an effective approach to achieve radicals by triggering electron transfer. However, catalytic version complex photoactivation is quite underdeveloped comparing well-established utilization electronically biased partners. In this work, we utilize 4-nitrophthalonitrile as acceptor facilitate efficient π-stacking with electron-rich aromatics form complex. The characterization and energy profiles on cocrystal 1,3,5-trimethoxybenzene disclose that transfer highly favorable under light irradiation. This catalyst can be efficiently applied in benzylic C−H bond developing Giese reaction alkylanisoles oxidation benzyl alcohols. A broad scope tolerated a mechanism also proposed. Moreover, corresponding π-anion interaction potassium formate further hydrocarboxylation alkenes efficiently.

Language: Английский

Citations

18
Long-Lived Charge-Transfer State from B–N Frustrated Lewis Pairs Enchained in Supramolecular Copolymers DOI Creative Commons
Beatrice Adelizzi, Pongphak Chidchob, Naoki Tanaka

et al.

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(39), P. 16681 - 16689

Published: Sept. 3, 2020

The field of supramolecular polymers is rapidly expanding; however, the exploitation these systems as functional materials still elusive. To become competitive, must display microstructural order and emergence new properties upon copolymerization. tackle this, a greater understanding relationship between monomers' design polymer microstructure required well set monomers that efficiently interact with one another to synergistically generate Here, we present first implementation frustrated Lewis pairs into copolymers. Two copolymers based on π-conjugated O-bridged triphenylborane two different triphenylamines formation B–N within chain. remarkably long lifetime circularly polarized nature resulting photoluminescence emission highlight possibility obtain an intermolecular charge transfer. These results are proposed be consequences enchainment 1D aggregates. Although it challenging precise molecular picture copolymer microstructure, random blocklike could deduced from combination optical spectroscopic techniques theoretical simulation.

Language: Английский

Citations

110
Tris(pentafluorophenyl)borane catalyzed C–C and C–heteroatom bond formation DOI
G. Vasanth Kumar, Sourav Roy, Indranil Chatterjee

et al.

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 19(6), P. 1230 - 1267

Published: Jan. 1, 2021

This review showcases a collective depiction on the potential utility of BCF as versatile catalyst to develop various synthetic transformations.

Language: Английский

Citations

76
Frustrated Radical Pairs: Insights from EPR Spectroscopy DOI Creative Commons
Ayan Dasgupta, Emma Richards, Rebecca L. Melen

et al.

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(1), P. 53 - 65

Published: Sept. 18, 2020

Abstract Progress in frustrated Lewis pair (FLP) chemistry has revealed the importance of main group elements catalysis, opening new avenues synthetic chemistry. Recently, reactivities pairs have been uncovered that disclose certain combinations acids and bases undergo single‐electron transfer (SET) processes. Here an electron can be transferred from basic donor to a acidic acceptor generate reactive radical (FRP). This minireview aims showcase recent advancements this emerging field covering synthesis pairs, with extensive highlights results Electron Paramagnetic Resonance (EPR) spectroscopy explain nature stability different species observed.

Language: Английский

Citations

74
Frustrated Radical Pairs in Organic Synthesis DOI
Minsoo Ju, Zhipeng Lu, Luiz F. T. Novaes

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 19478 - 19489

Published: Sept. 1, 2023

Frustrated radical pairs (FRPs) describe the phenomenon that two distinct radicals─which would otherwise annihilate each other to form a closed-shell covalent adduct─can coexist in solution, owing steric repulsion or weak bonding association. FRPs are typically formed via spontaneous single-electron transfer between sterically encumbered precursors─an oxidant and reductant─under ambient conditions. The components of FRP exhibit orthogonal chemical properties can often act cooperativity achieve interesting reactivities. Initially observed study traditional frustrated Lewis pairs, have recently been shown be capable homolytically activating various bonds. In this Perspective, we will discuss discovery FRPs, their fundamental reactivity bond activation, recent developments use synthetic organic chemistry, including C–H functionalization. We anticipate provide new reaction strategies for solving challenging problems modern synthesis.

Language: Английский

Citations

32
Radical reactions enabled by polyfluoroaryl fragments: photocatalysis and beyond DOI
Mikhail O. Zubkov, Alexander D. Dilman

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(9), P. 4741 - 4785

Published: Jan. 1, 2024

The review summarizes advances in the radical chemistry of polyfluorinated arenes under photocatalytic conditions. fluoroaryl fragment serves as enabling motif for reaction design and efficient generation reactive intermediates.

Language: Английский

Citations

9