Recent Advances in C–H Functionalisation through Indirect Hydrogen Atom Transfer DOI Creative Commons
Filip S. Meger, John A. Murphy

Molecules, Journal Year: 2023, Volume and Issue: 28(16), P. 6127 - 6127

Published: Aug. 18, 2023

The functionalisation of C–H bonds has been an enormous achievement in synthetic methodology, enabling new retrosynthetic disconnections and affording simple equivalents for synthons. Hydrogen atom transfer (HAT) is a key method forming alkyl radicals from substrates. Classic reactions, including the Barton nitrite ester reaction Hofmann–Löffler–Freytag reaction, among others, provided early examples HAT. However, recent developments photoredox catalysis electrochemistry have made HAT powerful tool capable introducing wide range functional groups into bonds. Moreover, greater mechanistic insights stimulated development increasingly site-selective protocols. Site-selectivity can be achieved through tuning electron density at certain using additives, judicious choice reagent, solvent system. Herein, we describe latest methods functionalizing C–H/Si–H/Ge–H indirect between 2018–2023, as well critical discussion reagents, aspects, substrate scopes, background contexts

Language: Английский

Photons or Electrons? A Critical Comparison of Electrochemistry and Photoredox Catalysis for Organic Synthesis DOI
Nicholas E. S. Tay, Dan Lehnherr, Tomislav Rovis

et al.

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2487 - 2649

Published: Nov. 9, 2021

Redox processes are at the heart of synthetic methods that rely on either electrochemistry or photoredox catalysis, but how do and catalysis compare? Both approaches provide access to high energy intermediates (e.g., radicals) enable bond formations not constrained by rules ionic 2 electron (e) mechanisms. Instead, they 1e mechanisms capable bypassing electronic steric limitations protecting group requirements, thus enabling chemists disconnect molecules in new different ways. However, while providing similar intermediates, differ several physical chemistry principles. Understanding those differences can be key designing transformations forging disconnections. This review aims highlight these similarities between comparing their underlying principles describing impact electrochemical photochemical methods.

Language: Английский

Citations

357
Visible light photocatalysis in the late-stage functionalization of pharmaceutically relevant compounds DOI
Rolando Cannalire, Sveva Pelliccia, Luca Sancineto

et al.

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 50(2), P. 766 - 897

Published: Dec. 22, 2020

Recent developments and future prospects of visible-light photocatalysis in the late-stage functionalization pharmaceuticals natural bioactive compounds.

Language: Английский

Citations

333
Advances in theE → ZIsomerization of Alkenes Using Small Molecule Photocatalysts DOI
Tomáš Neveselý,

Max Wienhold,

John J. Molloy

et al.

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2650 - 2694

Published: Aug. 27, 2021

Geometrical E → Z alkene isomerization is intimately entwined in the historical fabric of organic photochemistry and enjoying a renaissance (Roth et al. Angew. Chem., Int. Ed. Engl. 1989 28, 1193–1207). This consequence fundamental stereochemical importance Z-alkenes, juxtaposed with frustrations thermal reactivity that are rooted microscopic reversibility. Accessing excited state paradigms allow this latter obstacle to be circumnavigated by exploiting subtle differences photophysical behavior substrate product chromophores: provides molecular basis for directionality. While direct irradiation operationally simple, photosensitization via selective energy transfer enables augmentation repertoire include substrates not directly photons. Through sustained innovation, an impressive portfolio tailored small molecule catalysts range triplet energies now widely available facilitate contra-thermodynamic thermo-neutral reactions generate Z-alkene fragments. review intended serve as practical guide covering geometric alkenes enabled catalysis from 2000 2020, logical sequel excellent treatment Dugave Demange (Chem. Rev. 2003 103, 2475–2532). The mechanistic foundations underpinning selectivity discussed together induction models rationales explain counterintuitive directionality these processes which very distinguish product. Implications subsequent stereospecific transformations, application total synthesis, regioselective polyene isomerization, spatiotemporal control pre-existing configuration broader sense discussed.

Language: Английский

Citations

309
Recent developments in the difunctionalization of alkenes with C–N bond formation DOI
Xiang Chen, Fang Xiao, Wei‐Min He

et al.

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 8(18), P. 5206 - 5228

Published: Jan. 1, 2021

Various alkene difunctionalization reactions involving nitridization, diamination, azidation, oxyamination, carboamination, aminohalogenation, and nitration are introduced in this review.

Language: Английский

Citations

128
Recent advances in difunctionalization of alkenes using pyridinium salts as radical precursors DOI
Yanan Wang,

Yanyang Bao,

Meifang Tang

et al.

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(24), P. 3847 - 3864

Published: Jan. 1, 2022

This review summarises recent applications of pyridinium salts in radical-mediated difunctionalization alkenes. We hope this will provide a comprehensive overview topic and promote the wider development application salts.

Language: Английский

Citations

101
Transition-metal-catalyzed C–H bond alkylation using olefins: recent advances and mechanistic aspects DOI
Debasish Mandal,

Sumali Roychowdhury,

Jyoti Prasad Biswas

et al.

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(17), P. 7358 - 7426

Published: Jan. 1, 2022

Transition metal catalysis has contributed immensely to C-C bond formation reactions over the last few decades, and alkylation is no exception. The superiority of such methodologies traditional evident from minimal reaction steps, shorter times, atom economy while also allowing control regio- stereo-selectivity. In particular, hydrocarbonation alkenes grabbed increased attention due its fundamental ability effectively selectively synthesise a wide range industrially pharmaceutically relevant moieties. This review attempts provide scientific viewpoint systematic analysis recent developments in transition-metal-catalyzed various C-H bonds using simple activated olefins. key features mechanistic studies involved these transformations are described briefly.

Language: Английский

Citations

81
Enantioselective Deaminative Alkylation of Amino Acid Derivatives with Unactivated Olefins DOI
Shang‐Zheng Sun, Yueming Cai, Deliang Zhang

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(3), P. 1130 - 1137

Published: Jan. 14, 2022

Herein, we report the first Ni-catalyzed enantioselective deaminative alkylation of amino acid and peptide derivatives with unactivated olefins. Key for success was discovery a new sterically encumbered bis(oxazoline) ligand backbone, thus offering de novo technology accessing enantioenriched sp3–sp3 linkages via sp3 C–N functionalization. Our protocol is distinguished by its broad scope generality across wide number counterparts, even in context late-stage In addition, an remote hydroalkylation reaction internal olefins within reach, providing useful entry point forging centers at C–H sites.

Language: Английский

Citations

76
Photocatalytic C(sp3) radical generationviaC–H, C–C, and C–X bond cleavage DOI Creative Commons
Chia‐Yu Huang, Jianbin Li, Chao‐Jun Li

et al.

Chemical Science, Journal Year: 2022, Volume and Issue: 13(19), P. 5465 - 5504

Published: Jan. 1, 2022

C(sp 3 ) radicals (R˙) are of broad research interest and synthetic utility.

Language: Английский

Citations

75
Native Amides as Enabling Vehicles for Forging sp3–sp3 Architectures via Interrupted Deaminative Ni-Catalyzed Chain-Walking DOI Creative Commons
Jesus Rodrigalvarez, Hao Wang, Rubén Martı́n

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(7), P. 3869 - 3874

Published: Feb. 8, 2023

Herein, we disclose an interrupted deaminative Ni-catalyzed chain-walking strategy that forges sp3-sp3 architectures at remote, yet previously unfunctionalized, methylene sp3 C-H sites enabled by the presence of native amides. This protocol is characterized its mild conditions and wide scope, including challenging substrate combinations. Site-selectivity can be dictated a judicious choice ligand, thus offering opportunity to enable bond formations are otherwise inaccessible in conventional events.

Language: Английский

Citations

57
Recent Advances in Electron Donor‐Acceptor (EDA)‐Complex Reactions involving Quaternary Pyridinium Derivatives DOI

Barakha Saxena,

Roshan I. Patel,

Anuj Sharma

et al.

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(10), P. 1538 - 1564

Published: March 6, 2023

Abstract Quaternary pyridinium compounds are valuable intermediates in organic synthesis, which have gained immense popularity the synthetic community. The application of transition metal or photoredox catalysis transforming quaternary into various C−C and C−X bonds is well established. A majority these methods require high temperatures, expansive catalysts, delicate conditions for successful execution. On other hand, use metal‐free photocatalysis‐free strategies constructing using derivatives has been sought‐after. In this context, electron‐donor‐acceptor (EDA)‐complex reactions emerged as a state‐of‐the‐art methodology, do not any photocatalyst their EDA‐complex photochemistry takes advantage electron‐acceptor ability derivatives, can quickly generate radical precursor via deaminative process. These newly generated useful several transformations. We hereby, review, discuss an area major progress mediated involving with mechanism, substrate scope, limitations. magnified image

Language: Английский

Citations

44