Cobalt(III) Carbene Complex with an Electronic Excited-State Structure Similar to Cyclometalated Iridium(III) Compounds DOI Creative Commons
Narayan Sinha, Björn Pfund, Christina Wegeberg

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(22), P. 9859 - 9873

Published: May 27, 2022

Many organometallic iridium(III) complexes have photoactive excited states with mixed metal-to-ligand and intraligand charge transfer (MLCT/ILCT) character, which form the basis for numerous applications in photophysics photochemistry. Cobalt(III) analogous MLCT excited-state properties seem to be unknown yet, despite fact that cobalt(III) can adopt identical low-spin d6 valence electron configurations due their close chemical relationship. Using a rigid tridentate chelate ligand (LCNC), central amido π-donor is flanked by two σ-donating N-heterocyclic carbene subunits, we obtained robust homoleptic complex [Co(LCNC)2](PF6), featuring state substantial character. Compared vast majority of isoelectronic iron(II) complexes, [Co(LCNC)2](PF6) long-lived because it does not deactivate as efficiently into lower-lying metal-centered states; furthermore, engages directly photoinduced reactions. The comparison [Fe(LCNC)2](PF6), well structural, electrochemical, UV–vis transient absorption studies, provides insight new design principles first-row transition-metal photophysical photochemical reminiscent those known from platinum group metals.

Language: Английский

Photocatalytic Late-Stage C–H Functionalization DOI
Peter Bellotti, Huan‐Ming Huang,

Teresa Faber

et al.

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

Citations

336
Enantioselective Radical Reactions Using Chiral Catalysts DOI
Shovan Mondal, Frédéric Dumur, Didier Gigmès

et al.

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

Citations

265
Nitrogen-Centered Radicals in Functionalization of sp2 Systems: Generation, Reactivity, and Applications in Synthesis DOI Creative Commons
Cassie Pratley, Sabine Fenner, John A. Murphy

et al.

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(9), P. 8181 - 8260

Published: March 14, 2022

The chemistry of nitrogen-centered radicals (NCRs) has plentiful applications in organic synthesis, and they continue to expand as our understanding these reactive species increases. utility intermediates is demonstrated the recent advances C–H amination (di)amination alkenes. Synthesis previously challenging structures can be achieved by efficient functionalization sp2 moieties without prefunctionalization, allowing for faster more streamlined synthesis. This Review addresses generation, reactivity, application NCRs, including, but not limited to, iminyl, aminyl, amidyl, aminium species. Contributions from early discovery up most examples have been highlighted, covering radical initiation, thermolysis, photolysis, and, recently, photoredox catalysis. Radical-mediated intermolecular (hetero)arenes occur with a variety complex amine precursors, generating aniline derivatives, an important class drug development. Functionalization olefins achievable high anti-Markovnikov regioselectivity allows access difunctionalized when intermediate carbon are trapped. Additionally, reactivity NCRs harnessed rapid construction N-heterocycles such pyrrolidines, phenanthridines, quinoxalines, quinazolinones.

Language: Английский

Citations

246
Electrochemical reactor dictates site selectivity in N-heteroarene carboxylations DOI

Guo‐Quan Sun,

Peng Yu, Wen Zhang

et al.

Nature, Journal Year: 2023, Volume and Issue: 615(7950), P. 67 - 72

Published: Jan. 5, 2023

Language: Английский

Citations

186
Supramolecular Coordination Cages for Artificial Photosynthesis and Synthetic Photocatalysis DOI Creative Commons
Rens Ham, C. Jasslie Nielsen,

Sonja Pullen

et al.

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(9), P. 5225 - 5261

Published: Jan. 20, 2023

Because sunlight is the most abundant energy source on earth, it has huge potential for practical applications ranging from sustainable supply to light driven chemistry. From a chemical perspective, excited states generated by make thermodynamically uphill reactions possible, which forms basis storage into fuels. In addition, with light, open-shell species can be open up new reaction pathways in organic synthesis. Crucial are photosensitizers, absorb and transfer substrates various mechanisms, processes that highly depend distance between molecules involved. Supramolecular coordination cages well studied synthetically accessible vessels single cavities guest binding, ensuring close proximity of different components. Due high modularity their size, shape, nature metal centers ligands, ideal platforms exploit preorganization photocatalysis. Herein we focus application supramolecular photocatalysis artificial photosynthesis photo(redox) catalysis. Finally, brief overview immobilization strategies provides tools implementing devices. This review inspiration future design photocatalytic host-guest systems producing solar fuels complex molecules.

Language: Английский

Citations

171
Aroyl Fluorides as Bifunctional Reagents for Dearomatizing Fluoroaroylation of Benzofurans DOI Creative Commons
Xiaoye Yu, Qingyuan Meng, Constantin G. Daniliuc

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(16), P. 7072 - 7079

Published: March 22, 2022

The 2,3-dihydrobenzofuran scaffold is widely found in natural products and biologically active compounds. Herein, dearomatizing 2,3-fluoroaroylation of benzofurans with aroyl fluorides as bifunctional reagents to access 2,3-difunctionalized dihydrobenzofurans reported. reaction that occurs by cooperative NHC/photoredox catalysis provides 3-aroyl-2-fluoro-2,3-dihydrobenzofurans moderate good yield high diastereoselectivity. Cascades proceed via radical/radical cross-coupling a benzofuran radical cation generated the photoredox cycle neutral ketyl formed through NHC cycle. redox-neutral transformation exhibits broad substrate scope functional group compatibility. With anhydrides reagents, aroyloxyacylation achieved strategy can also be applied

Language: Английский

Citations

125
Photocatalyzed [2σ + 2σ] and [2σ + 2π] Cycloadditions for the Synthesis of Bicyclo[3.1.1]heptanes and 5- or 6-Membered Carbocycles DOI
Tin V. T. Nguyen, André Bossonnet, Matthew D. Wodrich

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(46), P. 25411 - 25421

Published: Nov. 7, 2023

We report the use of photocatalysis for homolytic ring-opening carbonyl cyclopropanes. In contrast to previous studies, our approach does not require a metal cocatalyst or strong reductant. The cyclopropanes can be employed both [2σ + 2σ] and 2π] annulation with either alkenes/alkynes bicyclo[1.1.0]butanes, yielding cyclopent-anes/-enes bicyclo[3.1.1]heptanes (BCHs), respectively. BCHs are promising bioisosteres 1,2,4,5 tetra-substituted aromatic rings. Mechanistic including density functional theory computation trapping experiment DMPO, support 1,3-biradical generated from cyclopropane as key intermediate these transformations.

Language: Английский

Citations

96
Local reaction environment in electrocatalysis DOI
Chaojie Chen, Huanyu Jin, Pengtang Wang

et al.

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(4), P. 2022 - 2055

Published: Jan. 1, 2024

Beyond conventional electrocatalyst engineering, recent studies have unveiled the effectiveness of manipulating local reaction environment in enhancing performance electrocatalytic reactions. The general principles and strategies environmental engineering for different processes been extensively investigated. This review provides a critical appraisal advancements aiming to comprehensively assess this emerging field. It presents interactions among surface structure, ions distribution electric field relation environment. Useful protocols such as interfacial reactant concentration, mass transport rate, adsorption/desorption behaviors, binding energy are in-depth discussed toward modifying Meanwhile, electrode physical structures cell configurations viable optimization methods environments. In combination with

Language: Английский

Citations

89
Recent advances in the electrochemical generation of 1,3-dicarbonyl radicals from C–H bonds DOI

Qinhui Wan,

Zhongyi Zhang,

Zhong‐Wei Hou

et al.

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(11), P. 2830 - 2848

Published: Jan. 1, 2023

Recent advances in the electrochemical generation of 1,3-dicarbonyl radicals from C–H bonds and their mechanistic insights synthetic applications have been summarized.

Language: Английский

Citations

80
Electrophotochemical Ce-Catalyzed Ring-Opening Functionalization of Cycloalkanols under Redox-Neutral Conditions: Scope and Mechanism DOI

Zhaoliang Yang,

Dali Yang, Jianye Zhang

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(30), P. 13895 - 13902

Published: July 21, 2022

Selective cleavage and functionalization of C–C bonds in alcohols is gaining increasing interest organic synthesis biomass conversion. In particular, the development redox-neutral catalytic methods with cheap catalysts clean energy utmost interest. this work, we report a versatile method for ring-opening cycloalkanols by electrophotochemical (EPC) cerium (Ce) catalysis. The EPC-Ce-enabled catalysis allows different ring sizes to be cleaved while tolerating broad range functional groups. Notably, presence chloride as counteranion electrolyte, protocol selectively leads formation C–CN, C–C, C–S, or C–oxime instead C–halide bond after β-scission. A preliminary mechanistic investigation indicates that redox-active Ce catalyst can tuned electro-oxidation photo-reduction, thus avoiding use an external oxidant. Spectroscopic characterizations (cyclic voltammetry, UV–vis, electron paramagnetic resonance, X-ray absorption fine structure) suggest Ce(III)/Ce(IV) pathway transformation, which Ce(IV)-alkoxide involved.

Language: Английский

Citations

78