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

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 2487 - 2649

Опубликована: Ноя. 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.

Язык: Английский

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Copper-Catalyzed Borylative Difunctionalization of π-Systems

ACS Catalysis, Год журнала: 2020, Номер 10(19), С. 11578 - 11622

Опубликована: Авг. 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.

Язык: Английский

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

ACS Catalysis, Год журнала: 2023, Номер 13(8), С. 5723 - 5732

Опубликована: Апрель 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.

Язык: Английский

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Recent Progress in Transition-Metal-Catalyzed Asymmetric Reductive Amination

ACS Catalysis, Год журнала: 2021, Номер 11(22), С. 13809 - 13837

Опубликована: Окт. 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.

Язык: Английский

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Photocatalytic Hydroaminoalkylation of Styrenes with Unprotected Primary Alkylamines

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(39), С. 15936 - 15945

Опубликована: Сен. 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.

Язык: Английский

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Controlling Stereoselectivity with Noncovalent Interactions in Chiral Phosphoric Acid Organocatalysis

Chemical Reviews, Год журнала: 2025, Номер unknown

Опубликована: Март 18, 2025

Chiral phosphoric acids (CPAs) have emerged as highly effective Brønsted acid catalysts in an expanding range of asymmetric transformations, often through novel multifunctional substrate activation modes. Versatile and broadly appealing, these benefit from modular tunable structures, compatibility with additives. Given the unique types noncovalent interactions (NCIs) that can be established between CPAs various reactants─such hydrogen bonding, aromatic interactions, van der Waals forces─it is unsurprising catalyst systems become a promising approach for accessing diverse chiral product outcomes. This review aims to provide in-depth exploration mechanisms by which impart stereoselectivity, positioning NCIs central feature connects broad spectrum catalytic reactions. Spanning literature 2004 2024, it covers nucleophilic additions, radical atroposelective bond formations, highlighting applicability CPA organocatalysis. Special emphasis placed on structural mechanistic features govern CPA-substrate well tools techniques developed enhance our understanding their behavior. In addition emphasizing details stereocontrolling elements individual reactions, we carefully structured this natural progression specifics broader, class-level perspective. Overall, findings underscore critical role catalysis significant contributions advancing synthesis.

Язык: Английский

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Strategies for the Catalytic Enantioselective Synthesis of α-Trifluoromethyl Amines

ACS Catalysis, Год журнала: 2020, Номер 10(21), С. 12507 - 12536

Опубликована: Окт. 12, 2020

The exploitation of the

Язык: Английский

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

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(19)

Опубликована: Март 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.

Язык: 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, Год журнала: 2023, Номер 62(27)

Опубликована: Май 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.

Язык: Английский

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

Chemical Communications, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

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

Язык: Английский

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