Photochemical Metal‐Hydride Hydrogen Atom Transfer Mediated Radical Hydrofunctionalization of Dienes and Allenes DOI

Huaipu Yan,

Jing‐Ran Shan, Lei Shi

et al.

ChemCatChem, Journal Year: 2023, Volume and Issue: 16(2)

Published: Nov. 17, 2023

The metal-hydride hydrogen atom transfer (MHAT) method is widely recognized as a powerful technique for functionalizing alkenes. However, its application in the functionalization of industrial feedstock dienes and allenes relatively rare due to challenges related chemo-selectivity. In recent studies, Co-porphines have been identified highly efficient catalysts under photoirradiation MHAT, demonstrating an exceptional level chemoselectivity allenes, while disregarding other simple olefins present. This novel enables selective reductive coupling pyridines with allylation aldehydes by combination Ti catalysis. Mechanistic studies density functional theory (DFT) calculations support idea that non-reversible atoms from cobalt hydride leading generation allyl radicals, key step catalytic cycle.

Language: Английский

Photo‐ and Electrochemical Cobalt Catalysed Hydrogen Atom Transfer for the Hydrofunctionalisation of Alkenes DOI Creative Commons

Samikshan Jana,

Victor J. Mayerhofer,

Christopher J. Teskey

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(41)

Published: May 15, 2023

Catalytic hydrogen atom transfer from metal-hydrides to alkenes allows feedstock olefins be used as alkyl radical precursors. The chemoselectivity of this process makes it an attractive synthetic tool and such has been regularly in synthesis complex molecules. However, onwards reactivity is limited by compatibility with the conditions which form key metal-hydride species. Now, through merger photocatalysis or electrochemistry, milder methods are emerging can unlock entirely new offer perspectives on expanding these unprecedented directions. This review outlines most recent developments electro- photochemical cobalt catalysed offers suggestions future outlook.

Language: Английский

Citations

57
Organo‐Mediator Enabled Electrochemical Deuteration of Styrenes DOI

Keming Yang,

Tian Feng, Youai Qiu

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(45)

Published: Sept. 12, 2023

Despite widespread use of the deuterium isotope effect, selective labeling chemical molecules remains a major challenge. Herein, facile and general electrochemically driven, organic mediator enabled deuteration styrenes with oxide (D2 O) as economical source was reported. Importantly, this transformation could be suitable for various electron rich mediated by triphenylphosphine (TPP). The reaction proceeded under mild conditions without transition-metal catalysts, affording desired products in good yields excellent D-incorporation (D-inc, up to >99 %). Mechanistic investigations means experiments cyclic voltammetry tests provided sufficient support transformation. Notably, method proved powerful tool late-stage biorelevant compounds.

Language: Английский

Citations

48
Photo‐ and Cobalt‐Catalyzed Synthesis of Heterocycles via Cycloisomerization of Unactivated Olefins DOI Creative Commons
Henry Lindner, Willi M. Amberg, Tristano C. Martini

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(19)

Published: Feb. 28, 2024

Abstract We report a general, intramolecular cycloisomerization of unactivated olefins with pendant nucleophiles. The reaction proceeds under mild conditions and tolerates ethers, esters, protected amines, acetals, pyrazoles, carbamates, arenes. It is amenable to N ‐, O as well C ‐nucleophiles, yielding number different heterocycles including, but not limited to, pyrrolidines, piperidines, oxazolidinones, lactones. Use both benzothiazinoquinoxaline organophotocatalyst Co‐salen catalyst obviates the need for stoichiometric oxidant or reductant. showcase utility protocol in late‐stage drug diversification synthesis several small natural products.

Language: Английский

Citations

19
Single‐Atom Nickel on Carbon Nitride Photocatalyst Achieves Semihydrogenation of Alkynes with Water Protons via Monovalent Nickel DOI
Tongtong Jia, Di Meng, Ran Duan

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(9)

Published: Jan. 10, 2023

Prospects in light-driven water activation have prompted rapid progress hydrogenation reactions. We describe a Ni2+ -N4 site built on carbon nitride for catalyzed semihydrogenation of alkynes, with supplying protons, powered by visible-light irradiation. Importantly, the photocatalytic approach developed here enabled access to diverse deuterated alkenes D2 O excellent deuterium incorporation. Under irradiation, evolution four-coordinate species into three-coordinate Ni+ was spectroscopically identified. In combination theoretical calculations, photo-evolved is posited as HO-Ni+ -N2 an uncoordinated, protonated pyridinic nitrogen, formed coupled reduction and dissociation. The paired Ni-N prompts hydrogen liberation from water, it renders desorption alkene preferred over further alkane, ensuring selectivity.

Language: Английский

Citations

39
Recent Advances in Deuteration Reactions† DOI
Hao Li, Shabbir Muhammad, Wu Li

et al.

Chinese Journal of Chemistry, Journal Year: 2023, Volume and Issue: 42(10), P. 1145 - 1156

Published: Dec. 26, 2023

Comprehensive Summary The deuteration of organic compounds has attracted more attentions in recent years for the potential applications new drug discovery and synthetic chemistry. For this purpose, many efficient deuterium labeling methodologies have been developed, including hydrogen isotope exchange (HIE), reductive deuteration, dehalogenative that allow synthesis selectively deuterated compounds. In last few years, great breakthroughs selective achieved interest molecules is rising. review, we summarized developments since 2021. Several types key processes incorporation reactions, H/D exchange, are introduced discussed. Key Scientists 2000s, Derdau Atzrodt's group made contributions to directing assisted noble‐metal catalyzed arenes labeled During same period, Sajiki co‐workers completed a series reactions by heterogeneous platinum‐group metal catalysts. Since 2015, Gregory Pieters developed ruthenium catalysts exchange. 2016, Chirik's presence homogeneous iron complex. David MacMillan coworkers photocatalyzed HIE α‐amino C(sp 3 )–H bonds. From 2020, nanoelectrodes were designed deuterations unactivated unsaturated bonds Zhang's group. Recently, Beller's several strategies isotopic using earth‐abundant Our review latest important

Language: Английский

Citations

30
Photocatalytic Metal Hydride Hydrogen Atom Transfer Mediated Allene Functionalization by Cobalt and Titanium Dual Catalysis DOI

Huaipu Yan,

Qian Liao, Yuqing Chen

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(24)

Published: April 12, 2023

Catalytic metal hydride hydrogen atom transfer (MHAT) reactions have proven to be a powerful method for alkene functionalization. This work reports the discovery of Co-porphines as highly efficient MHAT catalysts with loading only 0.01 mol % unprecedented chemoselective allene functionalization under photoirradiation. Moreover, newly developed bimetallic strategy by combination photo Co-MHAT and Ti catalysis enabled successful carbonyl allylation wide range amino, oxy, thio, aryl, alkyl-allenes providing expedient access valuable β-functionalized homoallylic alcohols in over 100 examples exceptional regio- diastereoselectivity. Mechanism studies DFT calculations supported that selectively transferring atoms from cobalt allenes generating allyl radicals is key step catalytic cycle.

Language: Английский

Citations

27
Photoinduced Cobalt Catalysis for the Reductive Coupling of Pyridines and Dienes Enabled by Paired Single‐Electron Transfer** DOI Creative Commons

Jingyang Qin,

Manuel Barday,

Samikshan Jana

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(45)

Published: Sept. 7, 2023

Abstract Selective hydroarylation of dienes has potential to provide swift access useful building blocks. However, most existing methods rely on stabilised by an aromatic group and transmetallation or nucleophilic attack steps require electron‐rich aryl coupling partners. As such, there are few examples which tolerate wide‐spread heteroarenes such as pyridine. Whilst allylic C−H functionalisation could be considered alternative approach, the positional selectivity unsymmetrical substrates is hard control. Here, we report a general approach for selective hydropyridylation under mild conditions using metal catalysed hydrogen‐atom transfer. Photoinduced, reductive enable simultaneous formation cobalt‐hydride catalyst persistent radical easily‐synthesised pyridyl phosphonium salts. This facilitates in traceless manner at C4‐position wide‐range pyridine substrates. The mildness method underscored its functional‐group tolerance demonstrated applications late‐stage functionalisation. Based combination experimental computational studies, propose mechanistic pathway proceeds through non‐reversible transfer (HAT) from cobalt hydride species uniquely presence other olefins due much higher relative barrier associated with olefin HAT.

Language: Английский

Citations

24
A modular approach to stereoselective homoaldol reaction via photoredox/Cr/Co triple catalysis DOI Creative Commons

Haigen Shen,

Zheng Zhang,

Zhaoxin Shi

et al.

Chem, Journal Year: 2024, Volume and Issue: 10(3), P. 998 - 1014

Published: Jan. 24, 2024

Language: Английский

Citations

14
Magnesium/methanol-d1: a practical reductive deuteration system for the deuterium labeling of α,β-unsaturated esters, nitriles and amides DOI

Penghui Ma,

J. Q. Li,

Lei Sun

et al.

Organic & Biomolecular Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

The use of magnesium and methanol in the reduction various functional groups has been well established. In this study, we present a reductive deuteration system using Mg/CH

Language: Английский

Citations

1
Role of Heavy Water in the Synthesis and Nanocatalytic Activity of Gold Nanoparticles DOI Creative Commons
Nathaniel E. Larm, Christopher D. Stachurski, Paul C. Trulove

et al.

ACS Nanoscience Au, Journal Year: 2025, Volume and Issue: 5(1), P. 52 - 59

Published: Jan. 7, 2025

Heavy water (D2O) has found extensive application as a moderator in nuclear reactors. Additionally, it serves substitute for regular (H2O) biological or spectroscopic experiments, providing deuterium source and addressing challenges related to solvent opacity contrast. This is particularly relevant experiments involving neutron scattering, infrared absorption, magnetic resonance. However, replacing H2O with D2O not always straightforward harmless substitution can instead have unintended chemical consequences. In this study, we highlight the significant impact of deuteration on two common gold nanoparticle syntheses-borohydride reduction ascorbic acid reduction-by comparing reactions mixtures thereof. The resulting colloids exhibit differences size spectral characteristics, their effectiveness nanocatalysts widely used 4-nitrophenol benchmark reaction adversely affected by presence during both particle synthesis catalytic medium. Ultimately, these results underscore critical awareness often overlooked scientists engineers: despite its widespread sometimes indispensable use analytical spectroscopy, cellular imaging, biophysics, organic chemistry, cannot truly replace without significantly altering environment reaction.

Language: Английский

Citations

1