Photochemical and Electrochemical Applications of Proton-Coupled Electron Transfer in Organic Synthesis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2017 - 2291

Published: Nov. 23, 2021

We present here a review of the photochemical and electrochemical applications multi-site proton-coupled electron transfer (MS-PCET) in organic synthesis. MS-PCETs are redox mechanisms which both an proton exchanged together, often concerted elementary step. As such, MS-PCET can function as non-classical mechanism for homolytic bond activation, providing opportunities to generate synthetically useful free radical intermediates directly from wide variety common functional groups. introduction practitioner’s guide reaction design, with emphasis on unique energetic selectivity features that characteristic this class. then chapters oxidative N–H, O–H, S–H, C–H homolysis methods, generation corresponding neutral species. Then, reductive PCET activations involving carbonyl, imine, other X═Y π-systems, heteroarenes, where ketyl, α-amino, heteroarene-derived radicals be generated. Finally, we asymmetric catalysis materials device applications. Within each chapter, subdivide by group undergoing homolysis, thereafter type transformation being promoted. Methods published prior end December 2020 presented.

Language: Английский

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Hantzsch esters: an emerging versatile class of reagents in photoredox catalyzed organic synthesis

Organic & Biomolecular Chemistry, Journal Year: 2019, Volume and Issue: 17(29), P. 6936 - 6951

Published: Jan. 1, 2019

This minireview highlights the recent advances in chemistry of Hantzsch esters photoredox catalyzed organic synthesis, with particular emphasis placed on reaction mechanisms.

Language: Английский

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Enantioselective Radical Reactions Using Chiral Catalysts

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(6), P. 5842 - 5976

Published: Jan. 24, 2022

Benefiting from the impressive increase in fundamental knowledge, last 20 years have shown a continuous burst of new ideas and consequently plethora catalytic methods for enantioselective radical reactions. This review aims to provide complete survey progress achieved over this latter period. The first part focuses on use chiral organocatalysts, these include catalysts covalently linked substrate those that interact with by weaker interactions like hydrogen bonds. second is devoted transition-metal redox catalysis which organized according increasing atomic number first-row transition metals (Ti, Cr, Fe, Mn, Co, Ni, Cu). Bioinspired manganese- iron-mediated hydroxylations oxidations are also discussed. A specific section dedicated reactivity Ru, Rh, Ir complexes as Lewis acids special focus at metal. Absorption photons result different events such energy transfer, single-electron hydrogen-atom transfer facilitating formation radicals. Organocatalysis has been successfully combined photocatalysts, opened pathways enlarging precursors available. merger photocatalysis organo- or metalla-photocatalysis brought novelty allowed discovery large original transformations. enzyme-catalyzed reactions involving intermediates largely benefit visible-light irradiation included review. provides comprehensive inventory goal detailing reaction mechanisms involved transformations any nonspecialist could find their own creativity invent yet unknown applications.

Language: Английский

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Exploiting attractive non-covalent interactions for the enantioselective catalysis of reactions involving radical intermediates

Nature Chemistry, Journal Year: 2020, Volume and Issue: 12(11), P. 990 - 1004

Published: Oct. 19, 2020

Language: Английский

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Ynamide Smiles Rearrangement Triggered by Visible-Light-Mediated Regioselective Ketyl–Ynamide Coupling: Rapid Access to Functionalized Indoles and Isoquinolines

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(7), P. 3636 - 3644

Published: Jan. 31, 2020

In the past decades, significant advances have been made on radical Smiles rearrangement. However, eventually formed intermediates in these reactions are limited to amidyl radical, except for few examples initiated by a N-centered radical. Here, novel and practical rearrangement triggered photoredox-catalyzed regioselective ketyl-ynamide coupling is reported, which represents first of ynamides. This method enables facile access variety valuable 2-benzhydrylindoles with broad substrate scope generally good yields under mild reaction conditions. addition, this chemistry can also be extended divergent synthesis versatile 3-benzhydrylisoquinolines through similar rearrangement, followed dehydrogenative oxidation. Moreover, such an ynamide intermolecular photoredox catalysis via addition external sources achieved. By control experiments, was shown proceed key ketyl α-imino carbon intermediates.

Language: Английский

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α-Amino Radicals via Photocatalytic Single-Electron Reduction of Imine Derivatives

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(3), P. 2009 - 2025

Published: Jan. 21, 2020

The construction and manipulation of amine-containing architectures is importance to academic industrial development discovery programs. photochemical single-electron reduction imine derivatives generate α-amino radical intermediates has emerged as a powerful umpolung strategy for opening up underexplored routes such amine motifs. Furthermore, these radicals have been shown engage in wide variety chemistry, including radical–radical coupling, addition electrophiles, reductive amination chemistry. concept also begun see application iminium ion the extension enantiocontrolled C–C bond formation. This Perspective covers recent efforts this synthetic simple complex structures alike.

Language: Английский

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Photophysical Properties and Redox Potentials of Photosensitizers for Organic Photoredox Transformations

Synlett, Journal Year: 2021, Volume and Issue: 33(12), P. 1154 - 1179

Published: Feb. 15, 2021

Abstract Photoredox catalysis has proven to be a powerful tool in synthetic organic chemistry. The rational design of photosensitizers with improved photocatalytic performance constitutes major advancement photoredox transformations. This review summarizes the fundamental ground-state and excited-state photophysical electrochemical attributes molecular photosensitizers, which are important determinants their reactivity.

Language: Английский

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Enantioselective [2π + 2σ] Cycloadditions of Bicyclo[1.1.0]butanes with Vinylazaarenes through Asymmetric Photoredox Catalysis

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(12), P. 8372 - 8380

Published: March 18, 2024

Here we present a highly enantioselective [2π + 2σ] photocycloaddition of bicyclo[1.1.0]butanes (BCBs). The reaction uses variety vinylazaarenes as partners and is catalyzed by polycyclic aromatic hydrocarbon (PAH)-containing chiral phosphoric acid bifunctional photosensitizer. A wide array pharmaceutically important bicyclo[2.1.1]hexane (BCH) derivatives have been synthesized with high yields, enantioselectivity, diastereoselectivity. In addition to the diverse 1-ketocarbonyl-3-substituted BCBs, α/β-substituted are compatible such an unprecedented photoredox catalytic pathway, resulting in successful assembly all-carbon quaternary stereocenter or two adjacent tertiary stereocenters on product.

Language: Английский

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Controlling Stereoselectivity with Noncovalent Interactions in Chiral Phosphoric Acid Organocatalysis

Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: March 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.

Language: Английский

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Rational synthesis of interpenetrated 3D covalent organic frameworks for asymmetric photocatalysis

Chemical Science, Journal Year: 2019, Volume and Issue: 11(6), P. 1494 - 1502

Published: Dec. 19, 2019

Covalent organic frameworks (COFs) show great promise as heterogeneous photocatalysts, but they have not yet been explored for asymmetric photocatalysis, which is important the sustainable production of pharmaceuticals and fine chemicals.

Language: Английский

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