New Strategies for the Transition-Metal Catalyzed Synthesis of Aliphatic Amines

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(5), P. 2613 - 2692

Published: Feb. 17, 2020

Transition-metal catalyzed reactions that are able to construct complex aliphatic amines from simple, readily available feedstocks have become a cornerstone of modern synthetic organic chemistry. In light the ever-increasing importance across range chemical sciences, this review aims provide concise overview transition-metal approaches alkylamine synthesis and their functionalization. Selected examples amine bond forming include: (a) hydroamination hydroaminoalkylation, (b) C(sp3)–H functionalization, (c) visible-light-mediated photoredox catalysis.

Language: Английский

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Copper’s rapid ascent in visible-light photoredox catalysis

Science, Journal Year: 2019, Volume and Issue: 364(6439)

Published: May 2, 2019

Visible-light photoredox catalysis offers a distinct activation mode complementary to thermal transition metal catalyzed reactions. The vast majority of processes capitalizes on precious ruthenium(II) or iridium(III) complexes that serve as single-electron reductants oxidants in their photoexcited states. As low-cost alternative, organic dyes are also frequently used but general suffer from lower photostability. Copper-based photocatalysts rapidly emerging, offering not only economic and ecological advantages otherwise inaccessible inner-sphere mechanisms, which have been successfully applied challenging transformations. Moreover, the combination conventional with copper(I) copper(II) salts has emerged an efficient dual catalytic system for cross-coupling

Language: Английский

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Visible Light-Induced Transition Metal Catalysis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1543 - 1625

Published: Oct. 8, 2021

In recent years, visible light-induced transition metal catalysis has emerged as a new paradigm in organic photocatalysis, which led to the discovery of unprecedented transformations well improvement known reactions. this subfield complex serves double duty by harvesting photon energy and then enabling bond forming/breaking events mostly via single catalytic cycle, thus contrasting established dual photocatalysis an exogenous photosensitizer is employed. addition, approach often synergistically combines catalyst–substrate interaction with photoinduced process, feature that uncommon conventional photoredox chemistry. This Review describes early development advances emerging field.

Language: Английский

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Photoinduced Deaminative Borylation of Alkylamines

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(34), P. 10700 - 10704

Published: Aug. 9, 2018

An operationally simple deaminative borylation reaction of primary alkylamines has been developed. The formation electron-donor-acceptor complexes between N-alkylpyridinium salts and bis(catecholato)diboron enables photoinduced single-electron transfer fragmentation to carbon-centered radicals, which are subsequently borylated. mild conditions allow a diverse range readily available be efficiently converted into synthetically valuable alkylboronic esters under catalyst-free conditions.

Language: Английский

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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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Enantioselective Photochemical Reactions Enabled by Triplet Energy Transfer

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1626 - 1653

Published: July 6, 2021

For molecules with a singlet ground state, the population of triplet states is mainly possible (a) by direct excitation and subsequent intersystem crossing or (b) energy transfer from an appropriate sensitizer. The latter scenario enables catalytic photochemical reaction in which sensitizer adopts role catalyst undergoing several cycles photon absorption to substrate. If product molecule triplet-sensitized process chiral, this can proceed enantioselectively upon judicious choice chiral An enantioselective also occur dual approach which, apart achiral sensitizer, second activates substrate toward sensitization. Although idea reactions via intermediates has been pursued for more than 50 years, notable selectivities exceeding 90% enantiomeric excess (ee) have only realized past decade. This review attempts provide comprehensive survey on various were rendered

Language: Английский

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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 Organic Reactions under Visible Light: Recent Developments and Future Perspectives

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(16), P. 9170 - 9196

Published: July 20, 2020

The development of transition metal (TM) catalysis for organic synthesis under visible light without recourse to typical photoredox catalysts has become a rapidly growing area research and been actively explored in the past several years. Distinct from extensively developed catalysis, which photocatalyst generally does not directly participate bond-forming process, photocatalyst/TM synergistic absorbs photon energy transfers TM catalyst through redox or transfer this Review focuses on summarizing recent developments photocatalytic reactions that use complexes both absorb catalytic bond formation involving covalently bonded intermediate. contents are categorized by used (Pd, Cu, Co, Ni, Mn, Au, Rh, Fe, Ru), with descending sequence according number examples reported each metal, provide an overview April 2020. Future perspectives personal opinions regarding expanding field also discussed.

Language: Английский

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Single Electron Transfer-Induced Redox Processes Involving N-(Acyloxy)phthalimides

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(3), P. 1640 - 1683

Published: Jan. 20, 2021

The past decade has witnessed the emergence of N-(acyloxy)phthalimides (NHPI esters) and its derivatives at forefront synthetic methods facilitating construction diverse molecular frameworks from readily available carboxylic acid feedstock. NHPI esters are predisposed to undergo reductive fragmentation via a single electron transfer (SET) process under thermal, photochemical, or electrochemical conditions generate corresponding carbon- nitrogen-centered radicals that participate in multitude transformations forge carbon–carbon carbon–heteroatom bonds. chemistry involving received broad applicability not only well-designed cascade annulations but also medicinal natural product synthesis. This comprehensive Review, broadly categorized according nature bond formation, details progress made this field since initial discovery by providing representative examples with mechanistic details, an emphasis on challenges future directions.

Language: Английский

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Catalysis with Palladium Complexes Photoexcited by Visible Light

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(34), P. 11586 - 11598

Published: Jan. 2, 2019

Abstract Palladium catalysis induced by visible light is an emerging field of catalysis. In contrast to classical reactions catalyzed Pd complexes in the ground state, which mostly proceed through two‐electron redox processes, mechanisms these new methods based on photoexcited usually operate transfer a single electron. Such processes lead putative hybrid Pd/radical species, exhibit both radical and Pd‐type reactivity. This Minireview highlights recent progress this rapidly growing area.

Language: Английский

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