Photocatalytic Late-Stage C–H Functionalization

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(8), P. 4237 - 4352

Published: Jan. 24, 2023

The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C–H functionalization approaches that make use low energy photons as a controllable source. Compared to traditional strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- chemoselectivities. Merging compelling benefits with workflow offers potentially unmatched arsenal tackle drug development campaigns beyond. This Review highlights photocatalytic strategies small-molecule drugs, agrochemicals, natural products, classified according targeted bond newly formed one. Emphasis is devoted identifying, describing, comparing main mechanistic scenarios. draws critical comparison between established ionic chemistry photocatalyzed radical-based manifolds. aims establish current state-of-the-art illustrate key unsolved challenges be addressed in future. authors aim introduce general readership functionalization, specialist practitioners evaluation methodologies, potential for improvement, future uncharted directions.

Language: Английский

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Transition-Metal-Catalyzed C–H Bond Activation for the Formation of C–C Bonds in Complex Molecules

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(12), P. 7692 - 7760

Published: May 10, 2023

Site-predictable and chemoselective C–H bond functionalization reactions offer synthetically powerful strategies for the step-economic diversification of both feedstock fine chemicals. Many transition-metal-catalyzed methods have emerged selective activation bonds. However, challenges regio- chemoselectivity with application to highly complex molecules bearing significant functional group density diversity. As molecular complexity increases within structures risks catalyst intolerance limited applicability grow number groups potentially Lewis basic heteroatoms. Given abundance bonds already diversified such as pharmaceuticals, natural products, materials, design selection reaction conditions tolerant catalysts has proved critical successful direct functionalization. such, innovations formation carbon–carbon been discovered developed overcome these limitations. This review highlights progress made metal-catalyzed C–C forming including alkylation, methylation, arylation, olefination targets.

Language: Английский

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Recent Advances in the Synthesis of Difluorinated Architectures from Trifluoromethyl Groups

Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 364(2), P. 234 - 267

Published: Nov. 29, 2021

Abstract Fluorine‐containing moieties are widely used in the pharmaceutical, agrochemical, and material fields. Thus, these structures of immense interest fields organic synthesis medicinal chemistry. Among various fluorinated groups, difluoromethyl unit has drawn increasing attention due to its unique pharmaceutical properties. In recent years, several methods for difluoromethylated compounds have been rapidly developed. However, most treat aromatic with excess difluoromethylating reagents, which often contain organometallic compounds, so transformations generally less environmentally friendly atom‐economical. this review, we summarize development new motifs or difluoroalkenes from trifluoromethylated trifluoromethyl alkenes via single C( sp 3 )−F bond cleavage. magnified image

Language: Английский

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Late-Stage C–H Functionalization of Azines

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(12), P. 7655 - 7691

Published: May 3, 2023

Azines, such as pyridines, quinolines, pyrimidines, and pyridazines, are widespread components of pharmaceuticals. Their occurrence derives from a suite physiochemical properties that match key criteria in drug design is tunable by varying their substituents. Developments synthetic chemistry, therefore, directly impact these efforts, methods can install various groups azine C–H bonds particularly valuable. Furthermore, there growing interest late-stage functionalization (LSF) reactions focus on advanced candidate compounds often complex structures with multiple heterocycles, functional groups, reactive sites. Because factors electron-deficient nature the effects Lewis basic N atom, distinct arene counterparts, application LSF contexts difficult. However, have been many significant advances reactions, this review will describe progress, much which has occurred over past decade. It possible to categorize radical addition processes, metal-catalyzed activation transformations occurring via dearomatized intermediates. Substantial variation reaction within each category indicates both rich reactivity heterocycles creativity approaches involved.

Language: Английский

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Difluoromethylation of Unactivated Alkenes Using Freon-22 through Tertiary Amine-Borane-Triggered Halogen Atom Transfer

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(31), P. 14288 - 14296

Published: July 27, 2022

The application of abundant and inexpensive fluorine feedstock sources to synthesize fluorinated compounds is an appealing yet underexplored strategy. Here, we report a photocatalytic radical hydrodifluoromethylation unactivated alkenes with industrial chemical, chlorodifluoromethane (ClCF2H, Freon-22). This protocol realized by merging tertiary amine-ligated boryl radical-induced halogen atom transfer (XAT) organophotoredox catalysis under blue light irradiation. A broad scope readily accessible featuring variety functional groups drug natural product moieties could be selectively difluoromethylated good efficiency in metal-free manner. Combined experimental computational studies suggest that the key XAT process ClCF2H both thermodynamically kinetically favored over hydrogen pathway owing formation strong boron–chlorine (B–Cl) bond low-lying antibonding orbital carbon–chlorine (C–Cl) bond.

Language: Английский

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Photoinduced Hydrodifluoromethylation and Hydromethylation of Alkenes Enabled by Ligand-to-Iron Charge Transfer Mediated Decarboxylation

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(3), P. 1300 - 1310

Published: Jan. 11, 2024

Directly utilizing abundant and inexpensive sources of aliphatic carboxylic acids is highly attractive for the synthesis CF2H- CH3-containing compounds. Herein, we report a versatile photoinduced iron-catalyzed platform hydrodifluoromethylation hydromethylation alkenes without need additional stoichiometric oxidants. These two transformations are accomplished by visible-light-induced ligand-to-iron charge transfer open-shell activation system using industrial chemical difluoroacetic acetic as precursors postulated to operate via difluoromethyl methyl radical-mediated decarboxylation mechanism. Experimental results show that strategy also applicable difunctionalization unactivated alkenes. Meanwhile, this provides viable route pharmaceutically active molecules containing deuterated units. The protocol exhibits several features, including mild reaction conditions, divergent radical precursors, operational simplicity scalability, good chemo- regioselectivity, scalability supported continuous flow technology, ability provide high-value building blocks applications in one step.

Language: Английский

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Direct Bioisostere Replacement Enabled by Metallaphotoredox Deoxydifluoromethylation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(8), P. 5067 - 5073

Published: Feb. 16, 2024

The replacement of a functional group with its corresponding bioisostere is widely employed tactic during drug discovery campaigns that allows medicinal chemists to improve the ADME properties candidates while maintaining potency. However, incorporation bioisosteres typically requires lengthy de novo resynthesis potential candidates, which represents bottleneck in their broader evaluation. An alternative would be directly convert into at late stage. Herein, we report realization this approach through conversion aliphatic alcohols difluoromethylated analogues via merger benzoxazolium-mediated deoxygenation and copper-mediated C(sp3)–CF2H bond formation. utility method showcased variety complex compounds.

Language: Английский

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Standardized Approach for Diversification of Complex Small Molecules via Aryl Thianthrenium Salts

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 21, 2025

Thianthrenation is a useful strategy for the late-stage diversification of complex small molecules owing to positional selectivity and synthetic versatility thianthrenium salts as electrophilic linchpins. However, substrate-dependent identification suitable reaction conditions thianthrenation can be difficult. Reported functionalization vary significantly and, in some instances, lack robustness practicality. Herein, we report generalized approach preparation two manifolds practical, robust, parallel salts.

Language: Английский

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The emergence of the C–H functionalization strategy in medicinal chemistry and drug discovery

Chemical Communications, Journal Year: 2021, Volume and Issue: 57(83), P. 10842 - 10866

Published: Jan. 1, 2021

Owing to the market competitiveness and urgent societal need, an optimum speed of drug discovery is important criterion for successful implementation. Despite rapid ascent artificial intelligence computational bioanalytical techniques accelerate in big pharma, organic synthesis privileged scaffolds predicted silico vitro vivo studies still considered as rate-limiting step. C-H activation latest technology added into chemist's toolbox construction late-stage modification functional molecules achieve desired chemical physical properties. Particularly, elimination prefunctionalization steps, exceptional group tolerance, complexity-to-diversity oriented synthesis, functionalization medicinal expand space. It has immense potential a library molecules, structural required pharmacological properties such absorption, distribution, metabolism, excretion, toxicology (ADMET) attachment reporters proteome profiling, metabolite etc. preclinical studies. Although heterocycle modification, 18F labelling, methylation, via have been reviewed from synthetic standpoint, general overview these protocols aspects not reviewed. In this feature article, we will discuss recent trends methodologies through activation/annulation cascade; arylation sp2-sp2 sp2-sp3 cross-coupling; borylation/silylation introduce linchpin further manipulation; amination N-heterocycles hydrogen bond acceptors; fluorination/fluoroalkylation tune polarity lipophilicity; methylation: methyl magic discovery; peptide macrocyclization therapeutics biologics; fluorescent labelling radiolabelling bioimaging; bioconjugation biology studies; drug-metabolite biodistribution excretion diversification drug-molecules increase efficacy safety; cutting-edge DNA encoded improved chemistry discovery.

Language: Английский

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Visible-Light-Induced Radical Difluoromethylation/Cyclization of Unactivated Alkenes: Access to CF₂H-Substituted Quinazolinones

Organic Letters, Journal Year: 2021, Volume and Issue: 23(20), P. 7787 - 7791

Published: Sept. 28, 2021

A mild and efficient visible-light-induced radical difluoromethylation/cyclization of unactivated alkenes toward the synthesis substituted quinazolinones with easily accessible difluoromethyltriphenylphosphonium bromide has been developed. The transformation advantages wide functional group compatibility, a broad substrate scope, operational simplicity. benign protocol offers facile access to pharmaceutically valuable difluoromethylated polycyclic quinazolinones.

Language: Английский

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