Interfacial Ti−S Bond Modulated S‐Scheme MOF/Covalent Triazine Framework Nanosheet Heterojunctions for Photocatalytic C−H Functionalization DOI Creative Commons
Zhu Gao,

Yi Jian,

Song Yang

et al.

Angewandte Chemie, Journal Year: 2023, Volume and Issue: 135(27)

Published: May 3, 2023

Abstract Constructing photocatalyst systems to functionalize the inert C−H bonds has attracted extensive research interest. However, purposeful modulation of interfacial charge transfer in heterostructures remains a challenge, as it usually suffers from sluggish kinetics. Reported herein is an easy strategy construct heteroatom‐induced interface for developing titanium‐organic frameworks (MOF‐902) @ thiophene‐based covalent triazine (CTF‐Th) nanosheets S‐scheme heterojunctions with controllable oxygen vacancies (OVs). Specifically, Ti atoms were first anchored onto heteroatom site CTF‐Th nanosheets, and then grown into MOF‐902 via Ti−S linkage, generating OVs. Using situ X‐ray photoelectron spectroscopy (XPS), extended absorption fine structure (EXAFS) density functional theory (DFT) calculations, enhanced separation induced by moderate OVs pre‐designed was validated. The exhibited improved efficiency photocatalytic C3‐acylation indoles under mild conditions yield 8.2 times larger than pristine or enabled scope substrates (15 examples). This performance superior state‐of‐the‐art can be retained, without significant loss, after 12 consecutive cycles.

Language: Английский

Photochemical and Electrochemical Applications of Proton-Coupled Electron Transfer in Organic Synthesis DOI Creative Commons
Philip R. D. Murray, James H. Cox, Nicholas D. Chiappini

et al.

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2017 - 2291

Published: Nov. 23, 2021

We present here a review of the photochemical and electrochemical applications multi-site proton-coupled electron transfer (MS-PCET) in organic synthesis. MS-PCETs are redox mechanisms which both an proton exchanged together, often concerted elementary step. As such, MS-PCET can function as non-classical mechanism for homolytic bond activation, providing opportunities to generate synthetically useful free radical intermediates directly from wide variety common functional groups. introduction practitioner’s guide reaction design, with emphasis on unique energetic selectivity features that characteristic this class. then chapters oxidative N–H, O–H, S–H, C–H homolysis methods, generation corresponding neutral species. Then, reductive PCET activations involving carbonyl, imine, other X═Y π-systems, heteroarenes, where ketyl, α-amino, heteroarene-derived radicals be generated. Finally, we asymmetric catalysis materials device applications. Within each chapter, subdivide by group undergoing homolysis, thereafter type transformation being promoted. Methods published prior end December 2020 presented.

Language: Английский

Citations

352
Unraveling the Structure and Reactivity Patterns of the Indole Radical Cation in Regioselective Electrochemical Oxidative Annulations DOI
Xing Liu, Dali Yang, Zhao Liu

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(5), P. 3175 - 3186

Published: Jan. 27, 2023

Oxidation-induced strategy for inert chemical bond activation through highly active radical cation intermediate has exhibited unique reactivity. Understanding the structure and reactivity patterns of intermediates is crucial in mechanistic study will be beneficial developing new reactions. In this work, properties indole cations have been revealed using time-resolved transient absorption spectroscopy, situ electrochemical UV–vis, electron paramagnetic resonance (EPR) technique. Density functional theory (DFT) calculations were used to explain predict regioselectivity several oxidative annulations. Based on understanding inherent cations, two different regioselective annulations indoles successfully developed under oxidation conditions. Varieties furo[2,3-b]indolines furo[3,2-b]indolines synthesized good yields with high regioselectivities. Our insights into promote further development oxidation-induced functionalizations.

Language: Английский

Citations

64
Interfacial Ti−S Bond Modulated S‐Scheme MOF/Covalent Triazine Framework Nanosheet Heterojunctions for Photocatalytic C−H Functionalization DOI Creative Commons
Zhu Gao,

Yi Jian,

Song Yang

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(27)

Published: May 3, 2023

Constructing photocatalyst systems to functionalize the inert C-H bonds has attracted extensive research interest. However, purposeful modulation of interfacial charge transfer in heterostructures remains a challenge, as it usually suffers from sluggish kinetics. Reported herein is an easy strategy construct heteroatom-induced interface for developing titanium-organic frameworks (MOF-902) @ thiophene-based covalent triazine (CTF-Th) nanosheets S-scheme heterojunctions with controllable oxygen vacancies (OVs). Specifically, Ti atoms were first anchored onto heteroatom site CTF-Th nanosheets, and then grown into MOF-902 via Ti-S linkage, generating OVs. Using situ X-ray photoelectron spectroscopy (XPS), extended absorption fine structure (EXAFS) density functional theory (DFT) calculations, enhanced separation induced by moderate OVs pre-designed was validated. The exhibited improved efficiency photocatalytic C3-acylation indoles under mild conditions yield 8.2 times larger than pristine or enabled scope substrates (15 examples). This performance superior state-of-the-art can be retained, without significant loss, after 12 consecutive cycles.

Language: Английский

Citations

48
Electrifying green synthesis: recent advances in electrochemical annulation reactions DOI Creative Commons
Guilherme M. Martins, Geórgia C. Zimmer, Samuel R. Mendes

et al.

Green Chemistry, Journal Year: 2020, Volume and Issue: 22(15), P. 4849 - 4870

Published: Jan. 1, 2020

Herein, electrochemical annulations involving mediators and mediator-free conditions have been discussed. Also, the use of sacrificial electrodes has explored.

Language: Английский

Citations

114
Electrochemical 1,2‐Diarylation of Alkenes Enabled by Direct Dual C–H Functionalizations of Electron‐Rich Aromatic Hydrocarbons DOI

Jing‐Hao Qin,

Mu‐Jia Luo, Delie An

et al.

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(4), P. 1861 - 1868

Published: Oct. 20, 2020

Abstract A cobalt‐promoted electrochemical 1,2‐diarylation of alkenes with electron‐rich aromatic hydrocarbons via direct dual C−H functionalizations is described, which employs a radical relay strategy to produce polyaryl‐functionalized alkanes. Simply by using graphite rod cathode instead platinum plate cathode, chemoselectivity this shifted the dehydrogenative [2+2+2] cycloaddition 1,2‐diarylation, annulation, and dehydrogenation cascades leading complex 11,12‐dihydroindolo[2,3‐ ]carbazoles. Mechanistical studies indicate that key step for processes transformations aryl sp 2 ‐hybridized carbon‐centered radicals deprotonation corresponding cation intermediates bases.

Language: Английский

Citations

82
Rh(iii)-Catalyzed C(sp2)–H functionalization/cyclization cascade of N-carboxamide indole and iodonium reagents for access to indoloquinazolinone derivatives DOI

Zhipeng Han,

Mengmeng Xu, Ruiying Zhang

et al.

Green Chemistry, Journal Year: 2021, Volume and Issue: 23(17), P. 6337 - 6340

Published: Jan. 1, 2021

The sustainable synthesis of indoloquinazolinone derivatives from N -methoxycarbamoyl indoles and iodonium ylide reagents in methanol is described.

Language: Английский

Citations

42
Nickel-catalyzed decarboxylative cross-coupling of indole-3-acetic acids with aryl bromides by convergent paired electrolysis DOI
Zhenhua Wang, Lei Wei,

Ke‐Jin Jiao

et al.

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(59), P. 8202 - 8205

Published: Jan. 1, 2022

Herein, nickel-catalyzed decarboxylative cross-coupling of indole-3-acetic acids with aryl bromides by convergent paired electrolysis was developed in an undivided cell. This protocol features good functional group tolerance, and is chemical redox agent- sacrificial electrode-free. Mechanistic studies indicated that the base crucial for decarboxylation step a NiI/NiIII catalytic cycle involved this transformation.

Language: Английский

Citations

34
De Novo Construction of Chiral Aminoindolines by Cu-Catalyzed Asymmetric Cyclization and Subsequent Discovery of an Unexpected Sulfonyl Migration DOI

Baocheng Wang,

Tingting Fan,

Fen‐Ya Xiong

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(43), P. 19932 - 19941

Published: Oct. 21, 2022

Searching for efficient strategies to access structurally novel aminoindolines is of great significance drug discovery. However, catalytic asymmetric de novo construction aminoindoline scaffolds with functionality primed diversification still remains elusive. Here, we report a Cu-catalyzed cyclization ethynyl benzoxazinones amines, producing chiral 3-aminoindolines in good yield and high enantioselectivity (up 97% 98:2 er). Moreover, radical-mediated sulfonyl migration these products was unexpectedly found, further affording new bearing alkenyl groups retained enantiopurity 84% Bioactivity evaluations indicate that show notable antitumor activities chirality proven have significant impact on their activity.

Language: Английский

Citations

31
Novel multifunctional unimolecular initiators built on natural indole featuring fast photobleaching and visible light/thermal double polymerization DOI
Shang Gong, Xiang Wu,

Qiuyan Liao

et al.

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(7), P. 2730 - 2744

Published: Jan. 1, 2023

The fabricated photoinitiators IDs with green indole as the electron donor display highly efficient photobleaching and photoinitiation.

Language: Английский

Citations

18
A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis DOI Creative Commons
Nian Li, Ruzal Sitdikov, Ajit Prabhakar Kale

et al.

Beilstein Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 20, P. 2500 - 2566

Published: Oct. 9, 2024

With the resurgence of electrosynthesis in organic chemistry, there is a significant increase number routes available for late-stage functionalization (LSF) drugs. Electrosynthetic methods, which obviate need hazardous chemical oxidants or reductants, offer unprecedented control reactions through continuous variation applied potential and possibility combination with photochemical processes. This capability substantial advantage performing electrochemical photoelectrochemical LSF. Ultimately, these protocols are poised to become vital component medicinal chemist's toolkit. In this review, we discuss that have been demonstrated be applicable LSF pharmaceutical drugs, their derivatives, natural substrates. We present analyze representative examples illustrate electrochemistry photoelectrochemistry valuable molecular scaffolds.

Language: Английский

Citations

6