Photoelectrochemical C−H Alkylation of Heteroarenes with Organotrifluoroborates

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(14), P. 4592 - 4595

Published: Jan. 16, 2019

A photoelectrochemical method for the C-H alkylation of heteroarenes with organotrifluoroborates has been developed. The merger electrocatalysis and photoredox catalysis provides a chemical oxidant-free approach generation functionalization alkyl radicals from organotrifluoroborates. variety were functionalized using primary, secondary, tertiary alkyltrifluoroborates excellent regio- chemoselectivity.

Language: Английский

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Electroremovable Traceless Hydrazides for Cobalt-Catalyzed Electro-Oxidative C–H/N–H Activation with Internal Alkynes

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(25), P. 7913 - 7921

Published: May 29, 2018

Electrochemical oxidative C–H/N–H activations have been accomplished with a versatile cobalt catalyst in terms of [4 + 2] annulations internal alkynes. The electro-oxidative C–H activation manifold proved viable an undivided cell setup under exceedingly mild reaction conditions at room temperature using earth-abundant catalysts. electrochemical catalysis prevents the use transition metal oxidants catalysis, generating H2 as sole byproduct. Detailed mechanistic studies provided strong support for facile cobaltation by initially formed cobalt(III) catalyst. subsequent alkyne migratory insertion was interrogated mass spectrometry and DFT calculations, providing formation key seven-membered cobalta(III) cycle regioselective fashion. Key to success unprecedented alkynes represented N-2-pyridylhydrazides, which we developed traceless electrocleavage strategy electroreductive samarium temperature.

Language: Английский

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Anodic Oxidation for the Stereoselective Synthesis of Heterocycles

Accounts of Chemical Research, Journal Year: 2019, Volume and Issue: 53(1), P. 105 - 120

Published: Dec. 24, 2019

ConspectusStereodefined aliphatic heterocycles are one of the fundamental structural motifs observed in natural products and biologically active compounds. Various strategies for synthesis these building blocks based on transition metal catalysis, organocatalysis, noncatalytic conditions have been developed. Although electrosynthesis has also utilized functionalization heterocycles, stereoselective transformations under electrochemical still a challenging field electroorganic chemistry.This Account consists four main topics related to our recent efforts diastereo- and/or enantioselective especially N-heterocycles, using anodic oxidations as key steps. The first topic is development synthetic methods multisubstituted piperidines pyrrolidines from anodically prepared α-methoxy cyclic amines. Our were primarily N-acyliminium ion chemistry, diastereoselective methoxylation, arylation, deallylative methoxylation. Furthermore, we found unique property N-cyano protecting group that enabled α-methoxylation α-substituted second investigation memory chirality decarboxylative We methoxylation oxazolidine thiazolidine derivatives with appropriate N-protecting occurred stereospecific manner even though reaction proceeded through an sp2 planar carbon center. findings demonstrated example chemistry. third chiral azabicyclo-N-oxyls their application organocatalysis oxidative kinetic resolution secondary alcohols. final utilizing generated halogen cations. investigated amino alcohol bromo developed intramolecular C–C bond formation keto amides, bromoiminolactonization α-allyl malonamides, ring expansion allyl It noteworthy most reactions performed undivided cells constant-current conditions, which avoided complicated setup was beneficial large-scale reaction. In addition, some challenges hope research will contribute further construction valuable heterocyclic compounds approach.

Language: Английский

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Nickel‐Catalyzed Thiolation of Aryl Halides and Heteroaryl Halides through Electrochemistry

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(15), P. 5033 - 5037

Published: Feb. 8, 2019

Transition-metal-catalyzed coupling reactions are useful tools for synthesizing aryl sulfur compounds. However, conventional transition-metal-catalyzed thiolation of bromides and chlorides typically requires the use strong base under elevated reaction temperature. Herein, we report first examples nickel-catalyzed electrochemical in absence an external at room temperature using undivided cells.

Language: Английский

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Electrophotocatalytic Undirected C−H Trifluoromethylations of (Het)Arenes

Chemistry - A European Journal, Journal Year: 2019, Volume and Issue: 26(15), P. 3241 - 3246

Published: Dec. 25, 2019

Electrophotochemistry has enabled arene C-H trifluoromethylation with the Langlois reagent CF3 SO2 Na under mild reaction conditions. The merger of electrosynthesis and photoredox catalysis provided a chemical oxidant-free approach for generation radical. electrophotochemistry was carried out in an operationally simple manner, setting stage challenging trifluoromethylations unactivated arenes heteroarenes. robust nature electrophotochemical manifold reflected by wide scope, including electron-rich electron-deficient benzenes, as well naturally occurring Electrophotochemical further achieved flow modular electro-flow-cell equipped in-operando monitoring unit on-line flow-NMR spectroscopy, providing support single electron transfer processes.

Language: Английский

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Electricity-driven asymmetric Lewis acid catalysis

Nature Catalysis, Journal Year: 2018, Volume and Issue: 2(1), P. 34 - 40

Published: Dec. 4, 2018

Language: Английский

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Multicomponent reactions and photo/electrochemistry join forces: atom economy meets energy efficiency

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(6), P. 2313 - 2382

Published: Jan. 1, 2022

Visible-light photoredox catalysis has been regarded as an extremely powerful tool in organic chemistry, bringing the spotlight back to radical processes. The versatility of photocatalyzed reactions already demonstrated be effective providing alternative routes for cross-coupling well multicomponent reactions. photocatalyst allows generation high-energy intermediates through light irradiation rather than using highly reactive reagents or harsh reaction conditions. In a similar vein, electrochemistry experienced fruitful renaissance generating without need any catalyst. Such milder approaches pose basis toward higher selectivity and broader applicability. electrochemical reactions, species acts starter cascade events. This diverse reactivity use is usually not covered by classical methods. Owing availability cheaper more standardized photo- reactors, easily scalable flow-setups, it surprising that these two fields have become areas increased research interest. Keeping view, this review aimed at overview synthetic design MCRs involving and/or activation crucial step with particular focus on choice difunctionalized reagent.

Language: Английский

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Electrochemical generation of nitrogen-centered radicals for organic synthesis

Green Synthesis and Catalysis, Journal Year: 2021, Volume and Issue: 2(2), P. 165 - 178

Published: March 29, 2021

There is a resurgence of interests in organic electrochemistry, which generally accepted as green synthetic tool. In this context, many electrochemical methods have been developed the past decade to access various nitrogen-centered radicals (NCRs) from readily available precursors controlled fashion, enabling rapid development NCR-mediated new reactions for construction nitrogen-containing compounds. review, recent advances chemistry electrochemically generated NCRs are critically highlighted, based on strategies their formation and types NCRs. Focus put mechanism generation different applications.

Language: Английский

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Direct C–H difluoromethylation of heterocycles via organic photoredox catalysis

Nature Communications, Journal Year: 2020, Volume and Issue: 11(1)

Published: Jan. 31, 2020

Abstract The discovery of modern medicine relies on the sustainable development synthetic methodologies to meet needs associated with drug molecular design. Heterocycles containing difluoromethyl groups are an emerging but scarcely investigated class organofluoro molecules potential applications in pharmaceutical, agricultural and material science. Herein, we developed organophotocatalytic direct difluoromethylation heterocycles using O 2 as a green oxidant. C–H oxidative obviates need for pre-functionalization substrates, metals additives. operationally straightforward method enriches efficient synthesis many difluoromethylated moderate excellent yields. pharmaceutical moleculars demonstrates practicability this methodology late-stage development. Moreover, 2′-deoxy-5-difluoromethyluridine (F TDR) exhibits promising activity against some cancer cell lines, indicating that might provide assistance discovery.

Language: Английский

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Recent Advances on the Electrochemical Difunctionalization of Alkenes/Alkynes

Chinese Journal of Chemistry, Journal Year: 2019, Volume and Issue: 37(3), P. 292 - 301

Published: Feb. 6, 2019

Electroorganic synthesis is an emerging area of high impact research in organic chemistry, which considered as one the green and efficient methods attracts growing attention. In this review, we summarized comprehensively recent literature reports on electrochemical oxidative difunctionalization unsaturated C—C bonds. The reaction types described review included intermolecular cyclization, intramolecular alkenes/alkynes. This focuses discussion its synthetic generality for preparation functionalized compounds related mechanism.

Language: Английский

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