Dual Nickel/Photoredox‐Catalyzed Synthesis of N‐formyl N,N’‐Diaryl Ethylenediamines via Multiple C−N/C−C Coupling of Nitroarenes with Trimethylamine DOI
Tongtong Zheng, Zhe Chuan Feng, Jun‐An Ma

et al.

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(14), P. 2377 - 2384

Published: June 21, 2023

Abstract N , ’‐Diaryl ethylenediamines are common feedstocks in organic synthesis and important structural motifs medicinal chemistry. Whereas the C−N formation reactions based on anilines aryl halides most direct methods to access ’‐diaryl ethylenediamines, photocatalytic synthetic version remains undeveloped. Herein we describe dual nickel/photoredox‐catalyzed amination reaction using nitroarenes trimethylamine as substrates. This cascade transformation hinges multiple C−C coupling events nitrogen radical α‐aminomethyl derived from nitroarene trimethylamine, respectively. A variety of ‐formyl can be obtained under protocol. Subsequent hydrolysis offers for further derivatizations.

Language: Английский

γ-Amino C(sp3)–H Functionalization of Aliphatic Amines through a Light-Driven Triple Catalysis DOI

Masanari Nakagawa,

Kazunori Nagao, Hirohisa Ohmiya

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(10), P. 8005 - 8012

Published: May 9, 2024

We report intra- and intermolecular γ-amino C(sp3)–H functionalization of aliphatic amines using a vinylsulfone-based HAT (hydrogen atom transfer) auxiliary triple catalysis, which is composed photoredox, cobalt, Brønsted acid catalysts under visible light irradiation. The process accomplishes four elementary steps: (i) electrophilic carbon-centered radical formation on the via MHAT (metal hydride hydrogen reaction, (ii) generation through 1,6-HAT (iii) single-electron oxidation to carbocation equivalents, (iv) nucleophilic substitution with internal or external nucleophiles. As result, this afforded γ-amino-functionalized products, such as azetidines, 1,3-diamine, 1,3-aminoalcohol derivatives.

Language: Английский

Citations

4
Sustainable Electrochemical Benzylic C‐H Oxidation Using MeOH as an Oxygen Source DOI

Meng Xue,

Tao Pan,

Zhichao Shao

et al.

ChemSusChem, Journal Year: 2024, Volume and Issue: 17(10)

Published: Jan. 16, 2024

Abstract New methods and strategies for the direct oxidation of benzylic C−H bonds are highly desirable, owing to importance ketone motifs in significant organic transformations synthesis valuable molecules, including pharmaceuticals, pesticides, fine chemicals. Herein, we describe an electrochemical strategy ketones using MeOH as oxygen source. Inexpensive safe KBr serves both electrolyte a bromide radical precursor reaction. This transformation also offers several advantages such mild conditions, broad functional group tolerance, operational simplicity. Mechanistic investigations by control experiments, scavenging electron paramagnetic resonance (EPR), kinetic studies, cyclic voltammetry (CV), in‐situ Fourier transform infrared (FTIR) spectroscopy support pathway involving formation benzyl methyl ether via hydrogen atom transfer (HAT) single‐electron (SET). The practical application our is highlighted successful five namely lenperone, melperone, diphenhydramine, cinnarizine, flunarizine.

Language: Английский

Citations

3
Thermodynamic H-Abstraction Abilities of Nitrogen Centered Radical Cations as Potential Hydrogen Atom Transfer Catalysts in Y–H Bond Functionalization DOI Creative Commons
Xia Zhao, Yilin Hou,

Bao‐Chen Qian

et al.

ACS Omega, Journal Year: 2024, Volume and Issue: 9(24), P. 26708 - 26718

Published: June 4, 2024

Y–H bond functionalization has always been the focus of research interest in area organic synthesis. Direct hydrogen atom transfer (HAT) from is one most efficient and practical methods to activate bond. Recently, nitrogen centered radical cations were broadly utilized as H-abstraction catalysts bonds via HAT process. As a type catalyst, H-affinity significant thermodynamic parameter quantitatively evaluate potentials cations. In this work, pKa values 120 protonated N-containing compounds acetonitrile (AN) are predicted, H-affinities AN derived reduction using Hess' law. This work focuses on abilities enrich molecule library novel or H-abstractors provides valuable guidelines for application functionalization.

Language: Английский

Citations

3
Decatungstate-Photocatalyzed Hydroamidomethylation of Azobenzenes with N,N-Dimethylamides DOI
Jingya Yang,

Cunhui Wang,

Yating Han

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 19, 2024

A photocatalytic hydroamidomethylation of azobenzenes with N,N-dimethylamides has been developed. Using tetrabutylammonium decatungstate (TBADT) as a photocatalyst, an array and reacted smoothly under visible light irradiation, affording previously unreported N-amidomethyl-N,N′-diarylhydrazines in generally high yields. Mechanistic studies indicate that the reaction is enabled by TBADT-mediated hydrogen atom transfer (HAT) photocatalysis. This work fundamentally different from reported N,N-dimethylformamide azobenzenes.

Language: Английский

Citations

3
Site-selective α-C(sp3)–H arylation of dialkylamines via hydrogen atom transfer catalysis-enabled radical aryl migration DOI Creative Commons
Jie Xu, Ruihan Li,

Yijian Ma

et al.

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

Published: Aug. 8, 2024

Site-selective C(sp3)–H arylation is an appealing strategy to synthesize complex arene structures but remains a challenge facing synthetic chemists. Here we report the use of photoredox-mediated hydrogen atom transfer (HAT) catalysis accomplish site-selective α-C(sp3)–H dialkylamine-derived ureas through 1,4-radical aryl migration, by which wide array benzylamine motifs can be incorporated medicinally relevant systems in late-stage installation steps. In contrast previous efforts, this C–H protocol exhibits specific site-selectivity, proforming predominantly on sterically more-hindered secondary and tertiary α-amino carbon centers, while functionalization less-hindered N-methyl group effectively circumvented most cases. Moreover, diverse range multi-substituted piperidine derivatives obtained with excellent diastereoselectivity. Mechanistic computational studies demonstrate that rate-determining step for methylene initial H abstraction, whereas radical ipso cyclization bears highest energy barrier functionalization. The relatively lower activation free energies compared methylic bond lead exceptional site-selectivity. authors migration.

Language: Английский

Citations

2
Photocatalysis and Kinetic Resolution by Lithiation to Give Enantioenriched 2-Arylpiperazines DOI Creative Commons
Anjan Kumar Das, Anthony Choi, Iain Coldham

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(6), P. 987 - 991

Published: Feb. 3, 2023

Piperazines are important heterocycles in drug compounds. We report the asymmetric synthesis of arylpiperazines by photocatalytic decarboxylative arylation (metallaphotoredox catalysis) then kinetic resolution using n-BuLi/(+)-sparteine. This gave a range piperazines with very high enantioselectivities. Further functionalizations enantioenriched 2,2-disubstituted piperazines, and either N-substituent can be removed selectively. Late-stage piperazine derivatives were demonstrated, including compound glycogen synthase kinase (GSK)-3β inhibitor activity potential for treating Alzheimer's disease.

Language: Английский

Citations

5
Acridine/Lewis Acid Complexes as Powerful Photocatalysts: A Combined Experimental and Mechanistic Study DOI

Dillon R. L. Rickertsen,

Joshua D. Crow,

Tamal Das

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(19), P. 14574 - 14585

Published: Sept. 16, 2024

A class of in-situ generated Lewis acid (LA) activated acridine complexes is reported, which act as potent photochemical catalysts for the oxidation a variety protected secondary amines. Acridine/LA exhibit tunable excited state reduction potentials ranging from +2.07 to 2.38 V vs. SCE. The ytterbium triflate complex 3,6-di-t-butyl-9-mesitylacridine catalyzes Giese-type reaction Boc-protected amines with challenging conjugate acceptors such acrylates, that are inaccessible analogous acridinium (t-Bu-Mes-Acr⊕) catalyzed reaction. mechanism this was investigated using suite physical organic probes including intramolecular 13C kinetic isotope effects (KIEs), variable time normalization analysis (VTNA) kinetics, determination redox potentials, and computational studies. In by t-Bu-Mes-Acr⊕, mechanistic studies consistent single-electron transfer (SET) ground-state reduced t-Bu-Mes-Acr• α-keto radical intermediate first irreversible step in catalytic cycle. Intriguingly, we find acridine/LA better ground reductants (-0.72 -0.74 vs SCE) relative (-0.59 predict increased substrate reactivity stems lower energy barrier key SET event.

Language: Английский

Citations

1
Dual Nickel/Photoredox‐Catalyzed Synthesis of N‐formyl N,N’‐Diaryl Ethylenediamines via Multiple C−N/C−C Coupling of Nitroarenes with Trimethylamine DOI
Tongtong Zheng, Zhe Chuan Feng, Jun‐An Ma

et al.

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(14), P. 2377 - 2384

Published: June 21, 2023

Abstract N , ’‐Diaryl ethylenediamines are common feedstocks in organic synthesis and important structural motifs medicinal chemistry. Whereas the C−N formation reactions based on anilines aryl halides most direct methods to access ’‐diaryl ethylenediamines, photocatalytic synthetic version remains undeveloped. Herein we describe dual nickel/photoredox‐catalyzed amination reaction using nitroarenes trimethylamine as substrates. This cascade transformation hinges multiple C−C coupling events nitrogen radical α‐aminomethyl derived from nitroarene trimethylamine, respectively. A variety of ‐formyl can be obtained under protocol. Subsequent hydrolysis offers for further derivatizations.

Language: Английский

Citations

2