Photons or Electrons? A Critical Comparison of Electrochemistry and Photoredox Catalysis for Organic Synthesis

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

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Copper-Catalyzed Borylative Difunctionalization of π-Systems

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(19), P. 11578 - 11622

Published: Aug. 25, 2020

Organoboronates represent a cornerstone functional group in modern synthesis owing to their unique reactivity and divergent synthetic capability. Copper catalysis has become one of the most powerful methods stereoselectively install boron across diverse π-systems. Additionally, this method affords tremendous versatility enabled by difunctionalization π-system addition an electrophile. This review covers known electrophiles intercept catalytic intermediates borylative strategies that have been reported up end May 2020.

Language: Английский

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Donor–Acceptor Mixed-Naphthalene Diimide-Porphyrin MOF for Boosting Photocatalytic Oxidative Coupling of Amines

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(8), P. 5723 - 5732

Published: April 12, 2023

Integrating electron donor and acceptor chromophores as ligands within one MOF for light harvesting photocatalysis appears to be a major synthesis challenge. Meanwhile, high-efficiency selective aerobic oxidative coupling of amines imines under mild conditions is highly desirable scientific industrial fields. Herein, via facile one-pot synthetic strategy, an porphyrin ligand 5,15-di(p-benzoato)porphyrin (H2DPBP) was successfully integrated into naphthalene diimide (electron acceptor)-based Zr-MOF (Zr-NDI) construct mixed-ligand (Zr-NDI-H2DPBP) benefiting from the two with similar geometry connectivity. When utilized heterogeneous photocatalyst benzylamine at room temperature, prepared Zr-NDI-H2DPBP exhibited boosted imine generation rate (136 mmol g–1 h–1) far exceeding those other noble-metal-free photocatalysts can applied various derivatives. Furthermore, results experiments density functional theory calculations, photocatalytic performance attributed photoinduced transfer H2DPBP NDI energy facilitated by photosensitized irradiation, which effectively improve electron–hole separation efficiency generate abundant reactive active species superoxide radical (O2•–) singlet oxygen (1O2), respectively. This work provides avenue chromophore-based light-harvesting systems utilizing MOFs platforms boost solar-energy conversion.

Language: Английский

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Recent Progress in Transition-Metal-Catalyzed Asymmetric Reductive Amination

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(22), P. 13809 - 13837

Published: Oct. 29, 2021

Asymmetric reductive amination (ARA) of a prochiral carbonyl compound with an amine using H2/hydrogen surrogate is concise and operationally simple method for the synthesis chiral amines. ARA proceeds via condensation group amine/ammonia followed by enantioselective reduction generated intermediate. The activation reductant stereoselective transfer hydrogen to intermediate imine/enamine often mediated transition metal catalyst. Considering wide applications enantiopure amines in pharmaceuticals, agrochemicals, materials, development effective catalysts has been intensively pursued last two decades. Since first report Blaser 1999, this key research area grown significantly recent years, as reflected advances catalyst design, diversifying substrate scope better mechanistic understanding. Several highly efficient general methodologies applicable challenging partners have demonstrated, providing ready access variety In Review, we present progress featuring diverse employing metal-catalysts. This Review provides organized critical discussion on engineering evolution, expanding susbstrate insights. To conclude, remaining challenges opportunities are also highlighted.

Language: Английский

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Photocatalytic Hydroaminoalkylation of Styrenes with Unprotected Primary Alkylamines

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(39), P. 15936 - 15945

Published: Sept. 20, 2021

Catalytic, intermolecular hydroaminoalkylation (HAA) of styrenes provides a powerful disconnection for pharmacologically relevant γ-arylamines, but current methods cannot utilize unprotected primary alkylamines as feedstocks. Metal-catalyzed HAA protocols are also highly sensitive to α-substitution on the amine partner, and no catalytic solutions exist α-tertiary γ-arylamine synthesis via this approach. We report solution these problems using organophotoredox catalysis, enabling direct, modular, sustainable preparation α-(di)substituted including challenging electron-neutral moderately electron-rich aryl groups. A broad range functionalities tolerated, reactions can be run multigram scale in continuous flow. The method is applied concise, protecting-group-free blockbuster drug Fingolimod, well phosphonate mimic its vivo active form (by iterative α-C–H functionalization ethanolamine). reaction sequenced with an intramolecular N-arylation provide general modular access valuable (spirocyclic) 1,2,3,4-tetrahydroquinolines 1,2,3,4-tetrahydronaphthyridines. Mechanistic kinetic studies support irreversible hydrogen atom transfer activation alkylamine by azidyl radical some contribution from chain. photon-limited exhibits zero-order dependence amine, azide, photocatalyst, first-order styrene.

Language: Английский

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Enantioselective Reductive (Hetero)Arylation of Cyclic N‐Sulfonyl Imines by Cobalt Catalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(19)

Published: March 14, 2023

Transition-metal-catalyzed enantioselective addition of aryl organometallic reagents to imines has emerged as one the most powerful tools for formation optically active diarylmethylamines. Here, we report first asymmetric reductive (hetero)arylations using and heteroaryl halides enabled by a chiral cobalt-bisphosphine catalyst. This approach shows good functional group compatibility complements reported strategy without use reagents. Mechanistic investigations supported that aryl-cobalt, instead an arylzinc reagent, was formed in situ this aryl-addition event.

Language: Английский

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Strategies for the Catalytic Enantioselective Synthesis of α-Trifluoromethyl Amines

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(21), P. 12507 - 12536

Published: Oct. 12, 2020

The exploitation of the

Language: Английский

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Copper‐Catalyzed Enantioconvergent Radical C(sp³)−N Cross‐Coupling: Access to α,α‐Disubstituted Amino Acids

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(27)

Published: May 8, 2023

Abstract Transition‐metal catalyzed enantioconvergent cross‐coupling of tertiary alkyl halides with ammonia offers a rapid avenue to chiral unnatural α,α‐disubstituted amino acids. However, the construction C−N bonds between tertiary‐carbon electrophiles and nitrogen nucleophiles presented great challenge owing steric congestion. We report copper‐catalyzed radical sulfoximines (as surrogates) under mild conditions by employing anionic N,N,N‐ligand long spreading side arm. An array acid derivatives were obtained good efficiency enantioselectivity. The synthetic utility strategy has been showcased elaboration coupling products into different α‐fully substituted amine building blocks.

Language: Английский

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Direct C(sp3)-H functionalization with aryl and alkyl radicals as intermolecular hydrogen atom transfer (HAT) agents

Chemical Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Recent years have witnessed the emergence of direct intermolecular C(sp

Language: Английский

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Recent Advances in Catalytic Enantioselective Synthesis of Fluorinated α‐ and β‐Amino Acids

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(22), P. 4763 - 4793

Published: Sept. 23, 2020

Abstract Enantioenriched fluorinated α‐ and β‐amino acids are often encountered in numerous pharmaceuticals bioactive molecules, also of great importance as probes PET NMR for studying the behavior enzymes incorporation into peptides drug candidates. Among various synthetic strategies developed, catalytic enantioselective synthesis proves to be one most facile powerful protocols construct such privileged structures. The past decade has witnessed considerable progress construction chiral acid derivatives with structural diversity. In this review, we summarize these impressive achievements according bond‐forming way or acids, respectively, underline remaining challenges. This information would provide important guidance some inspiration researchers engaged organic fluorine medicinal chemistry. magnified image

Language: Английский

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