Recent advances in transition-metal-catalyzed carbene insertion to C–H bonds

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(7), P. 2759 - 2852

Published: Jan. 1, 2022

C-H functionalization has been emerging as a powerful method to establish carbon-carbon and carbon-heteroatom bonds. Many efforts have devoted transition-metal-catalyzed direct transformations of Metal carbenes generated in situ from transition-metal compounds diazo or its equivalents are usually applied the transient reactive intermediates furnish catalytic cycle for new C-C C-X bond formation. Using this strategy unactivated simple alkanes complex molecules can be further functionalized transformed multi-functionalized compounds. In area, carbene insertion bonds paid continuous attention. Diverse catalyst design strategies, synthetic methods, potential applications developed. This critical review will summarize advance dated up July 2021, by categories aliphatic C(sp3)-H, aryl (aromatic) C(sp2)-H, heteroaryl (heteroaromatic) C(sp2)-H bonds, alkenyl alkynyl C(sp)-H, well asymmetric more coverage given recent work. Due rapid development future directions topic also discussed. give authors an overview chemistry with focus on systems

Language: Английский

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Lightening Diazo Compounds?

ACS Sustainable Chemistry & Engineering, Journal Year: 2021, Volume and Issue: 9(27), P. 8895 - 8918

Published: June 25, 2021

The development of new sustainable reactions and protocols is essential to fulfill the growing demands every branch organic chemistry for greener synthetic methodologies. In this context, use visible light as only source energy highly appealing. Since diazo compounds are valuable reagents in synthesis, their transformations realized a manner interest. High reactivity easy availability make them suitable solar-driven transformations. Indeed, photochemical have recently proven alternative transition metal catalysis. perspective, we highlight applications these under irradiation, particularly focusing on recent advancements. These include generation carbenes radicals which involve many relevant reactions, [2+1]-cycloadditions, X–H C–H insertions, Wolff rearrangement, more. Mechanistic aspects processes briefly addressed give readers deeper understanding rules underlying photoreactivity compounds. We conclude by emphasizing significant advancements discussing challenges future developments photochemistry reagents.

Language: Английский

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Unlocking novel reaction pathways of diazoalkanes with visible light

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(17), P. 2788 - 2798

Published: Jan. 1, 2022

In this feature article, the photolysis and dye-sensitized reactions of diazoalkanes are discussed applications in organic synthesis presented.

Language: Английский

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Cobalt-Catalyzed Nitrogen Atom Insertion in Arylcycloalkenes

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(49), P. 22433 - 22439

Published: Nov. 30, 2022

Developing strategies enabling the modification of underlying molecular frameworks facilitates access to underexplored chemical spaces. Skeletal editing is an emerging technology for late-stage diversification bioactive molecules. However, current state this knowledge remains undeveloped. This work describes a simple protocol that "inserts" nitrogen atom into arylcycloalkenes form corresponding N-heterocycles. The use inexpensive cobalt catalyst under aqueous and open-air conditions makes very practical. Examples compounds pharmaceutical interest complex fused ring further demonstrated potentially broad applicability methodology.

Language: Английский

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Diastereoselective Transfer of Tri(di)fluoroacetylsilanes‐Derived Carbenes to Alkenes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(25)

Published: April 13, 2022

Stereoselective cyclopropanation reaction of alkenes is usually achieved by metal complexes via singlet-metal-carbene intermediates. However, previous transition-metal-catalyzed with acylsilanes afforded low diastereoselectivity. Herein, we report the first visible-light-induced transition-metal-free terminal trifluoroacetylsilanes and difluoroacetylsilanes. Both aromatic aliphatic as well electron-deficient are suitable substrates for highly cis-selective [2+1] cyclization reaction. A combination experimental computational studies identified triplet carbenes being key intermediates in this transformation. The gram scale late-stage functionalization demonstrated synthetic potential strategy.

Language: Английский

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Visible Light-Induced Reactions of Diazo Compounds and Their Precursors

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(11), P. 7214 - 7261

Published: May 16, 2024

In recent years, visible light-induced reactions of diazo compounds have attracted increasing attention in organic synthesis, leading to improvement existing reactions, as well the discovery unprecedented transformations. Thus, photochemical or photocatalytic generation both carbenes and radicals provide milder tools toward these key intermediates for many valuable However, vast majority transformations represent new reactivity modes compounds, which are achieved by decomposition photoredox catalysis. particular, use a redox-active photocatalysts opens avenue plethora radical reactions. The application methods led inaccessible classical associated with metal carbenes. most cases, act sources but can also serve acceptors. Importantly, described processes operate under mild, practical conditions. This Review describes this subfield compound chemistry, particularly focusing on advancements.

Language: Английский

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Visible light-mediated photolysis of organic molecules: the case study of diazo compounds

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(48), P. 7346 - 7360

Published: Jan. 1, 2023

This article discusses the photochemistry of several diazo compounds undergoing visible light-mediated photolysis to generate free carbenes (or other highly reactive intermediates), which can be sequentially trapped by different reacting partners.

Language: Английский

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Photochemical Carbene Transfer Reactions of Aryl/Aryl Diazoalkanes—Experiment and Theory**

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(24), P. 13271 - 13279

Published: March 9, 2021

Controlling the reactivity of carbene intermediates is a key parameter in development selective transfer reactions and usually achieved by metal complexes via singlet metal-carbene intermediates. In this combined experimental computational studies, we show that free diaryl carbenes can be controlled electronic properties substituents without need external additives. The introduction electron-donating -withdrawing groups results significant perturbation triplet energy splitting intermediate activation energies consecutive reactions. This strategy now overcomes long-standing paradigm allows realization highly chemoselective with alkynes. We could readily accessed photolysis corresponding diazo compounds these undergo cyclopropenation, cascade, or C-H functionalization Experimental theoretical mechanistic analyses confirm participation different spin states rationalize for observed reactivity.

Language: Английский

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Visible Light-Promoted Transformation of Diazo Compounds via the Formation of Free Carbene as Key Intermediate

Chinese Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 41(12), P. 4565 - 4565

Published: Jan. 1, 2021

Carbene is one of the most important synthetic intermediates in organic synthesis.In past few decades, transition-metal catalyzed carbene transfer reactions have made remarkable development.Recently, visible light-promoted transformation diazo compounds through formation free as key intermediate begun to rise.The reaction only need light sole energy source which meets concept green chemistry.Since pioneering works developed by groups Diaves and Zhou, photo-promoted has attracted more attentions.On basis previous work, latest progress this field further improved, mainly focuses on recent new under irradiation contributions reported from Chinese research group.The future development direction, well challenges prospected.

Language: Английский

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Photocatalytic gem‐Difluoroolefination Reactions by a Formal C−C Coupling/Defluorination Reaction with Diazoacetates

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 61(4)

Published: Oct. 30, 2021

The photolysis of diazoalkanes to conduct singlet carbene transfer reactions colored has recently attracted significant interest in organic synthesis. Herein, we describe a photocatalytic approach that allows the access triplet intermediates via energy highly efficient gem-difluoroolefination with α-trifluoromethyl styrenes. use tertiary amines proved pivotal unlock this unusual reaction pathway and prevent undesired cyclopropanation pathways. amine further facilitates ultimate abstraction fluoride yield gem-difluoroolefins (43 examples, up 88 % yield), which is supported by experimental theoretical mechanistic studies. We explored synthesis method broad substrate scope, ranging from simple olefins heterocyclic towards decoration pharmaceutically relevant building blocks.

Language: Английский

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