Alkoxy Radicals See the Light: New Paradigms of Photochemical Synthesis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2429 - 2486

Published: Oct. 6, 2021

Alkoxy radicals are highly reactive species that have long been recognized as versatile intermediates in organic synthesis. However, their development has impeded due to a lack of convenient methods for generation. Thanks advances photoredox catalysis, enabling facile access alkoxy from bench-stable precursors and free alcohols under mild conditions, research interest this field renewed. This review comprehensively summarizes the recent progress radical-mediated transformations visible light irradiation. Elementary steps radical generation either or central reaction development; thus, each section is categorized discussed accordingly. Throughout review, we focused on different mechanisms well impact synthetic utilizations. Notably, catalytic abundant still early stage, providing intriguing opportunities exploit diverse paradigms.

Language: Английский

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Enantioselective Radical Reactions Using Chiral Catalysts

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(6), P. 5842 - 5976

Published: Jan. 24, 2022

Benefiting from the impressive increase in fundamental knowledge, last 20 years have shown a continuous burst of new ideas and consequently plethora catalytic methods for enantioselective radical reactions. This review aims to provide complete survey progress achieved over this latter period. The first part focuses on use chiral organocatalysts, these include catalysts covalently linked substrate those that interact with by weaker interactions like hydrogen bonds. second is devoted transition-metal redox catalysis which organized according increasing atomic number first-row transition metals (Ti, Cr, Fe, Mn, Co, Ni, Cu). Bioinspired manganese- iron-mediated hydroxylations oxidations are also discussed. A specific section dedicated reactivity Ru, Rh, Ir complexes as Lewis acids special focus at metal. Absorption photons result different events such energy transfer, single-electron hydrogen-atom transfer facilitating formation radicals. Organocatalysis has been successfully combined photocatalysts, opened pathways enlarging precursors available. merger photocatalysis organo- or metalla-photocatalysis brought novelty allowed discovery large original transformations. enzyme-catalyzed reactions involving intermediates largely benefit visible-light irradiation included review. provides comprehensive inventory goal detailing reaction mechanisms involved transformations any nonspecialist could find their own creativity invent yet unknown applications.

Language: Английский

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Catalytic enantioselective C(sp3)–H functionalization involving radical intermediates

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Jan. 20, 2021

Abstract Recently, with the boosted development of radical chemistry, enantioselective functionalization C( sp 3 )–H bonds via a pathway has witnessed renaissance. In principle, two distinct catalytic modes, distinguished by steps in which stereochemistry is determined (the formation step or step), can be devised. This Perspective discusses state-of-the-art area involving intermediates as well future challenges and opportunities.

Language: Английский

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Mechanism-based ligand design for copper-catalysed enantioconvergent C(sp3)–C(sp) cross-coupling of tertiary electrophiles with alkynes

Nature Chemistry, Journal Year: 2022, Volume and Issue: 14(8), P. 949 - 957

Published: May 26, 2022

Language: Английский

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Ligand Development for Copper-Catalyzed Enantioconvergent Radical Cross-Coupling of Racemic Alkyl Halides

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(38), P. 17319 - 17329

Published: Sept. 1, 2022

The enantioconvergent cross-coupling of racemic alkyl halides represents a powerful tool for the synthesis enantioenriched molecules. In this regard, first-row transition metal catalysis provides suitable mechanism stereoconvergence by converting to prochiral radical intermediates owing their good single-electron transfer ability. contrast noble development chiral nickel catalyst, copper-catalyzed is less studied. Besides enantiocontrol issue, major challenge arises from weak reducing capability copper that slows reaction initiation. Recently, significant efforts have been dedicated basic research aimed at developing ligands halides. This perspective will discuss advances in burgeoning area with particular emphasis on strategic anionic ligand design tune initiation under thermal conditions our group.

Language: Английский

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The Catalytic Formation of Atropisomers and Stereocenters via Asymmetric Suzuki–Miyaura Couplings

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(9), P. 4918 - 4937

Published: April 12, 2022

Although Suzuki–Miyaura cross-coupling is one of the most convenient and well-developed reactions, its applications to asymmetric version deliver highly functionalized atropisomers or nonracemic coupling products have been less explored. Besides some excellent work reported intermittently, reaction remains a significant challenge, particularly for preparing heterocyclic atropisomers. A concise but critical knowledge on this topic may further inspire researchers across various subdisciplines develop innovative practical solutions tackle problem. Therefore, Review aims summarize pioneering cross-couplings cover implementations via homogeneous heterogeneous catalysis during recent years. Most notably, use transition metals other than palladium also described.

Language: Английский

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Merging Halogen-Atom Transfer (XAT) and Copper Catalysis for the Modular Suzuki–Miyaura-Type Cross-Coupling of Alkyl Iodides and Organoborons

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(4), P. 1986 - 1992

Published: Jan. 21, 2022

We report here a mechanistically distinct approach to achieve Suzuki-Miyaura-type cross-couplings between alkyl iodides and aryl organoborons. This process requires copper catalyst but, in contrast with previous approaches based on palladium nickel systems, does not utilizes the metal for activation of electrophile. Instead, this strategy exploits halogen-atom-transfer ability α-aminoalkyl radicals convert secondary into corresponding that then are coupled aryl, vinyl, alkynyl, benzyl, allyl boronate species. These novel coupling reactions feature simple setup conditions (1 h at room temperature) facilitate access privileged motifs targeted by pharmaceutical sector.

Language: Английский

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Metalloradical Catalysis: General Approach for Controlling Reactivity and Selectivity of Homolytic Radical Reactions

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(20)

Published: March 13, 2024

Abstract Since Friedrich Wöhler's groundbreaking synthesis of urea in 1828, organic over the past two centuries has predominantly relied on exploration and utilization chemical reactions rooted two‐electron heterolytic ionic chemistry. While one‐electron homolytic radical chemistry is both rich fundamental reactivities attractive with practical advantages, synthetic application been long hampered by formidable challenges associated control reactivity selectivity high‐energy intermediates. To fully harness untapped potential for synthesis, there a pressing need to formulate radically different concepts broadly applicable strategies address these outstanding issues. In pursuit this objective, researchers have actively developing metalloradical catalysis (MRC) as comprehensive framework guide design general approaches controlling stereoselectivity reactions. Essentially, MRC exploits metal‐centered radicals present open‐shell metal complexes catalysts activation substrates generate metal‐entangled key intermediates govern reaction pathway stereochemical course subsequent catalytic processes. Different from conventional transition complexes, operates through utilizing stepwise mechanisms.

Language: Английский

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Enantioconvergent Cu-Catalyzed Radical C–N Coupling of Racemic Secondary Alkyl Halides to Access α-Chiral Primary Amines

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(37), P. 15413 - 15419

Published: Sept. 10, 2021

α-Chiral alkyl primary amines are virtually universal synthetic precursors for all other α-chiral N-containing compounds ubiquitous in biological, pharmaceutical, and material sciences. The enantioselective amination of common halides with ammonia is appealing potential rapid access to amines, but has hitherto remained rare due the multifaceted difficulties using underdeveloped C(sp3)-N coupling. Here we demonstrate sulfoximines as excellent surrogates enantioconvergent radical C-N coupling diverse racemic secondary (>60 examples) by copper catalysis under mild thermal conditions. reaction efficiently provides highly enantioenriched N-alkyl (up 99% yield >99% ee) featuring benzyl, propargyl, α-carbonyl alkyl, α-cyano stereocenters. In addition, have converted masked thus obtained various building blocks, ligands, drugs possessing N-functionalities, such carbamate, carboxylamide, tertiary amine, oxazoline, commonly seen α-substitution patterns. These results shine light on cross-coupling a general chiral carbon-heteroatom formation strategy.

Language: Английский

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Evolution in heterodonor P-N, P-S and P-O chiral ligands for preparing efficient catalysts for asymmetric catalysis. From design to applications

Coordination Chemistry Reviews, Journal Year: 2021, Volume and Issue: 446, P. 214120 - 214120

Published: July 19, 2021

The success of phosphine-oxazoline ligands (PHOX) inspired the progress in P-oxazoline ligand families by modifying either backbone, electronic and/or steric properties phosphine group or exchanging to a phosphinite phosphite group. In this respect, structures chiral have become more diverse and new very efficient emerged, which improved catalytic performance some asymmetric transformations, with an increased versatility, both range reactions substrates/reagents. addition, most are synthesized from easily accessible amino alcohols, maintaining short synthetic route developed for PHOX ligands. New been replacing oxazoline functionality several other N-donor groups, e.g. imidazole, thiazole, oxazole, pyridine, etc., O- S-groups. This review offers critical overview utility these successful bidentate heterodonor P-N, P-O P-S applied metal-mediated processes. We illustrate how, through proper design, can be excellent source ligands, superior many than best C2-symmetric N,N P,P-ligands reported so far.

Language: Английский

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