Toolbox for Distal C–H Bond Functionalizations in Organic Molecules

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(6), P. 5682 - 5841

Published: Oct. 18, 2021

Transition-metal-catalyzed C–H activation has developed a contemporary approach to the omnipresent area of retrosynthetic disconnection. Scientific researchers have been tempted take help this methodology plan their synthetic discourses. This paradigm shift helped in development industrial units as well, making synthesis natural products and pharmaceutical drugs step-economical. In vast zone bond activation, functionalization proximal bonds gained utmost popularity. Unlike bonds, distal is more strenuous requires distinctly specialized techniques. review, we compiled various methods adopted functionalize mechanistic insights within each these procedures, scope methodology. With give complete overview expeditious progress made field organic chemistry while also highlighting its pitfalls, thus leaving open for further modifications.

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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Chromium-Catalyzed Allylic Defluorinative Ketyl Olefin Coupling

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(30), P. 11602 - 11610

Published: July 22, 2021

Herein we report a chromium-catalyzed allylic defluorinative ketyl olefin coupling between aldehydes and α-trifluoromethyl alkenes, which provides novel efficient access to diverse gem-difluorohomoallylic alcohols. Remarkably, the high chemoselectivity of this reaction enables conversion formyl moiety in presence various easily reducible functionalities including ketone, organohalides, aziridine, sulfone, alkyne, unactivated alkene. The utility method is demonstrated by simple derivatizations attached hydroxyl group products. preliminary mechanistic investigations suggest pathway with rate-limiting C–C forming step followed facile β-fluoro elimination.

Language: Английский

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Photochemical and electrochemical strategies in C–F bond activation and functionalization

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 9(3), P. 853 - 873

Published: Dec. 7, 2021

The recent advances in photochemical or electrochemical C–F bond activation and functionalization have been summarized discussed.

Language: Английский

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Arenethiolate as a Dual Function Catalyst for Photocatalytic Defluoroalkylation and Hydrodefluorination of Trifluoromethyls

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(7), P. 4103 - 4109

Published: March 18, 2022

Thiol is known to act as a hydrogen atom transfer catalyst working in synergy with photocatalyst photoredox catalysis, but we report herein that an arene thiolate appropriate substituent can be photoactivated under visible light function both strongly reducing electron-donating redox and HAT enable catalytic C–F activation of trifluoromethyl substrates for selective hydrodefluorination coupling various alkenes the presence formate salts. These reactions demonstrate promising utility arenethiolates dual photocatalysts. The synthetic this method demonstrated by broad scope amenable substrates, including trifluoromethylated (hetero)arenes, trifluoroacetates, trifluoroacetamides, which exhibited high levels chemoselectivity. reaction efficacy allows site-selective late-stage functionalization multitrifluoromethylated bioactive compounds pharmaceuticals

Language: Английский

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Modular Access to Chiral α-(Hetero)aryl Amines via Ni/Photoredox-Catalyzed Enantioselective Cross-Coupling

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(19), P. 8797 - 8806

Published: May 3, 2022

Chiral α-aryl N-heterocycles are commonly found in natural products, pharmaceutical agents, and chiral catalysts but remain challenging to access via asymmetric catalysis. Herein, we report a general modular approach for the direct enantioselective α-arylation of saturated azacycles acyclic N-alkyl benzamides nickel/photoredox dual This process exploits hydrogen atom transfer ability photoeliminated chlorine radicals convert corresponding α-amino alkyl that then coupled with ubiquitous inexpensive (hetero)aryl chlorides. These coupling reactions require no oxidants or organometallic reagents, feature feedstock starting materials, broad substrate scope, high enantioselectivities, applicable late-stage diversification medicinally relevant complex molecules. Mechanistic studies suggest nickel catalyst uncommonly plays multiple roles, accomplishing radical generation, capture, cross-coupling, induction.

Language: Английский

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Synthetic Advantages of Defluorinative C−F Bond Functionalization

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(49)

Published: Aug. 22, 2023

Abstract Much progress has been made in the development of methods to both create compounds that contain C−F bonds and functionalize bonds. As such, are becoming common versatile synthetic functional handles. This review summarizes advantages defluorinative functionalization reactions for small molecule synthesis. The coverage is organized by type carbon framework fluorine attached mono‐ polyfluorinated motifs. main challenges, opportunities advances discussed each class organofluorine. Most text focuses on case studies illustrate how defluorofunctionalization can improve routes targets or properties enable unique mechanisms reactions. broader goal showcase incorporating exploiting design routes, improvement specific advent new methods.

Language: Английский

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Photocatalytic Three-Component Reductive Coupling Synthesis of gem-Difluorohomoallyl Secondary Amines

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 23, 2025

gem-Difluorohomoallyl amines, an important class of gem-difluoroalkenes, are prevalent moieties in many bioactive compounds. However, limited methods suitable for the synthesis this type compound containing secondary amines. Here, we display a photocatalytic multicomponent protocol gem-difluoroalkenes which makes use readily available materials: arylamines, alkyl aldehydes, and α-trifluoromethyl alkenes. Moreover, ketones amines also substrates. Preliminary mechanistic experiments indicate that key α-amino radical was involved, generated from reduction situ-formed imines (or iminium ions) by reduced photocatalyst. Subsequent addition to alkenes β-F elimination deliver desired products.

Language: Английский

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Recent advances in radical enabled selective C_sp³–F bond activation of multifluorinated compounds

Chemical Communications, Journal Year: 2021, Volume and Issue: 58(8), P. 1066 - 1077

Published: Dec. 24, 2021

Fluorine-containing molecules have found broad applications in pharmaceutical and agrochemical industries as introducing fluorine into a molecule could significantly tune the biological activities of parent molecules. Thus, synthesis fluorine-containing has received substantial attention over past few decades. As complementary strategy for fluorinated compounds through new Csp3-F bonds formation, selective cleavage inert from easily-available cost-effective multifluorinated molecules, such fluoroalkylaromatics, α-trifluoromethyl alkenes α-multifluorinated carbonyl compounds, been emerging an attractive alternative to access Moreover, inherent nature radical reactions offers opportunity functionalizations occur under mild conditions. In this regard, development photoredox catalysis, transition-metal or electrochemistry enable species generation via gained progress made recent years. This highlight summerizes advances single-electron-transfer enabled pathways.

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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