The generation of heteroatom-centred radicals (X˙), followed by intramolecular 1,5-hydrogen atom transfer (1,5-HAT) and the functionalisation of the translocated carbon-centred radicals, is the basic ...mechanism of the classic Hofmann-Löffler-Freytag (HLF) reaction and the Barton reaction. The chemoselectivity of the 1,5-HAT process is different from that of the transition metal-catalysed counterpart, providing, therefore, a complementary tool for remote C(sp3)-H bond functionalisation. There is a recent resurgence in this research field due to the emergence of visible light photocatalysis. This tutorial review summarises the recent progress in the remote functionalisation of C-H bonds featuring a key 1,5-HAT step with particular focus on photoredox-catalyzed remote C-H functionalisation.
Organic photocatalysts are emerging as viable and more sustainable tools than metal complexes. Recently, the field of organo‐photocatalysis has experienced an explosion in terms of applications, ...redesign of well‐established systems, and identification of novel scaffolds. A rational approach to the structural modification of the different photocatalysts is key to accessing unprecedented reactivity, while improving their catalytic performances. We herein discuss the concepts underpinning the scaffold modification of some of the most recently used photocatalysts and analyze how specific structural changes alter their physicochemical and redox properties.
No more trial and error! This Minireview outlines how a careful physicochemical properties analysis is instrumental towards the rational selection of a photocatalyst while delineating future applications and structural evolution.
Thermal C-C bond cleavage reactions allow the construction of structurally diverse molecular skeletons via predictable and efficient bond reorganizations. Visible light photoredox-catalyzed ...radical-mediated C-C bond cleavage reactions have recently emerged as a powerful alternative method for overcoming the thermodynamic and kinetic barrier of C-C bond cleavage in diverse molecular scaffolds. In recent years, a plethora of elegant and useful reactions have been invented, and the products are sometimes otherwise inaccessible by classic thermal reactions. Considering the great influence and synthetic potential of these reactions, we provide a summary of the state of art visible light-driven radical-mediated C-C bond cleavage/functionalization strategies with a specific emphasis on the working models. We hoped that this review will be useful for medicinal and synthetic organic chemists and will inspire further reaction development in this interesting area.
The merger of photoredox catalysis with transition metal catalysis, termed metallaphotoredox catalysis, has become a mainstay in synthetic methodology over the past decade. Metallaphotoredox ...catalysis has combined the unparalleled capacity of transition metal catalysis for bond formation with the broad utility of photoinduced electron- and energy-transfer processes. Photocatalytic substrate activation has allowed the engagement of simple starting materials in metal-mediated bond-forming processes. Moreover, electron or energy transfer directly with key organometallic intermediates has provided novel activation modes entirely complementary to traditional catalytic platforms. This Review details and contextualizes the advancements in molecule construction brought forth by metallaphotocatalysis.
The fields of C–H functionalization and photoredox catalysis have garnered enormous interest and utility in the past several decades. Many different scientific disciplines have relied on C–H ...functionalization and photoredox strategies including natural product synthesis, drug discovery, radiolabeling, bioconjugation, materials, and fine chemical synthesis. In this Review, we highlight the use of photoredox catalysis in C–H functionalization reactions. We separate the review into inorganic/organometallic photoredox catalysts and organic-based photoredox catalytic systems. Further subdivision by reaction classeither sp2 or sp3 C–H functionalizationlends perspective and tactical strategies for use of these methods in synthetic applications.
Conjugated microporous polymers (CMPs) are a unique class of materials that combine extended π-conjugation with a permanently microporous skeleton. Since their discovery in 2007, CMPs have become ...established as an important subclass of porous materials. A wide range of synthetic building blocks and network-forming reactions offers an enormous variety of CMPs with different properties and structures. This has allowed CMPs to be developed for gas adsorption and separations, chemical adsorption and encapsulation, heterogeneous catalysis, photoredox catalysis, light emittance, sensing, energy storage, biological applications, and solar fuels production. Here we review the progress of CMP research since its beginnings and offer an outlook for where these materials might be headed in the future. We also compare the prospect for CMPs against the growing range of conjugated crystalline covalent organic frameworks (COFs).
The development of photoinduced organocatalyzed atom transfer radical polymerization (O-ATRP) has received considerable attention since its introduction in 2014. Expanding on many of the advantages ...of traditional ATRP, O-ATRP allows well-defined polymers to be produced under mild reaction conditions using organic photoredox catalysts. As a result, O-ATRP has opened access to a range of sensitive applications where the use of a metal catalyst could be of concern, such as electronics, certain biological applications, and the polymerization of coordinating monomers. However, key limitations of this method remain and necessitate further investigation to continue the development of this field. As such, this review details the achievements made to-date as well as future research directions that will continue to expand the capabilities and application landscape of O-ATRP.
Can organic chemistry mimic nature in efficiency and sustainability? Not yet, but recent developments in photoredox catalysis animated the synthetic chemistry field, providing greener opportunities ...for industry and academia.
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 of the ever-increasing importance of aliphatic amines across the range of chemical sciences, this review aims to provide a concise overview of modern transition-metal catalyzed approaches to alkylamine synthesis and their functionalization. Selected examples of amine bond forming reactions include: (a) hydroamination and hydroaminoalkylation, (b) transition-metal catalyzed C(sp3)–H functionalization, and (c) transition-metal catalyzed visible-light-mediated light photoredox catalysis.
The use of visible light and photoredox catalysis emerged as a powerful and sustainable tool for organic synthesis, showing the high value of distinctly different ways of bond creation. Indoles and ...related heterocycles are widely-present in natural products, biologically active compounds, drugs, and agrochemicals. This review summarises the impact of visible light-promoted chemistry on the functionalization of indoles and on the synthesis and modification of indolines, indolin-2-ones, indolin-3-ones, and isatins. Almost 100 references starting from 2012 are cited.
The impact of visible light-promoted chemistry on the functionalization of indoles and related heterocycles is reviewed.
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