N‐(Acyloxy)phthalimides as Redox‐Active Esters in Cross‐Coupling Reactions

Advanced Synthesis & Catalysis, Journal Year: 2018, Volume and Issue: 360(9), P. 1735 - 1753

Published: Feb. 7, 2018

Abstract Recent years have witnessed a resurgence of novel, efficient and practical protocols for radical‐mediated cross‐coupling reactions involving N ‐(acyloxy)phthalimides (NHPI esters) as redox‐active esters. After the initial discovery properties NHPI esters, exciting examples SET‐based under thermal or photolytic conditions leading to diverse C–X (X=C, B, Si, Se, S) bonds been published. The operational simplicity broad applicability exhibited in ester‐based cross‐couplings bode well their widespread adoption. review presented herein covers all recent developments field ester (RAE)‐based since discovery. Depending on employed categorized into photoinduced non‐photoinduced with representative insightful mechanistic discussions. magnified image

Language: Английский

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Computational Ligand Descriptors for Catalyst Design

Chemical Reviews, Journal Year: 2019, Volume and Issue: 119(11), P. 6561 - 6594

Published: Feb. 25, 2019

Ligands, especially phosphines and carbenes, can play a key role in modifying controlling homogeneous organometallic catalysts, they often provide convenient approach to fine-tuning the performance of known catalysts. The measurable outcomes such catalyst modifications (yields, rates, selectivity) be set into context by establishing their relationship steric electronic descriptors ligand properties, models guide discovery, optimization, design In this review we present survey calculated descriptors, with particular focus on catalysis. A range different approaches calculating parameters are out compared, have collected for representative sets, including 30 monodentate phosphorus(III) donor ligands, 23 bidentate P,P-donor view providing useful resource analysis practitioners. addition, several case studies applications covering both maps models, been reviewed, illustrating how descriptor-led catalysis inform experiments highlighting good practice model comparison evaluation.

Language: Английский

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Well-Defined Palladium(II)–NHC Precatalysts for Cross-Coupling Reactions of Amides and Esters by Selective N–C/O–C Cleavage

Accounts of Chemical Research, Journal Year: 2018, Volume and Issue: 51(10), P. 2589 - 2599

Published: Sept. 21, 2018

Transition-metal-catalyzed cross-coupling reactions represent a most powerful tool for the rapid construction of C-C and C-X bonds available to synthetic chemists. Recently, tremendous progress has been made in burgeoning area amides esters enabled by regio- chemoselective acyl (X = N, O) cleavage using well-defined Pd(II)-NHC complexes. The use N-heterocyclic carbenes as ligands palladium-catalyzed cross-couplings permits that were previously impossible palladium or could be achieved only under harsh conditions. These provide an attractive method chemists manipulate traditionally inert amide ester with broad generality inherent catalysis. Research stable electrophiles can broadly categorized type electrophile undergoing cross-coupling. Recent studies have shown transition-metal catalysis represents one straightforward wide-ranging ways manipulating classically into generic acyl-metal intermediates systematically exploited new paradigm organic synthesis. key achieving high chemoselectivity process is control amidic resonance (nN πC═O* conjugation, rotation ca. 15-20 kcal/mol planar amides), enabling oxidative addition N-C bond metal rational predictable manner. This mode extended C(acyl)-O aryl esters, where selective C-O accomplished through match nucleophilic catalysts. two types transition-metal-catalyzed concept chemistry because ubiquity precursors Furthermore, stability provides unprecedented opportunities orthogonal strategies presence other electrophiles. In this Account, we highlight advances taken place past few years field focusing on both (1) stereoelectronic properties complexes critical realize challenging manifold (2) role isomerization barrier broader sense, described here practical approach functionalize common functional groups synthesis establishes access enable nonconventional strategies.

Language: Английский

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Photons or Electrons? A Critical Comparison of Electrochemistry and Photoredox Catalysis for Organic Synthesis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2487 - 2649

Published: Nov. 9, 2021

Redox processes are at the heart of synthetic methods that rely on either electrochemistry or photoredox catalysis, but how do and catalysis compare? Both approaches provide access to high energy intermediates (e.g., radicals) enable bond formations not constrained by rules ionic 2 electron (e) mechanisms. Instead, they 1e mechanisms capable bypassing electronic steric limitations protecting group requirements, thus enabling chemists disconnect molecules in new different ways. However, while providing similar intermediates, differ several physical chemistry principles. Understanding those differences can be key designing transformations forging disconnections. This review aims highlight these similarities between comparing their underlying principles describing impact electrochemical photochemical methods.

Language: Английский

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Palladium-Catalyzed Cross-Coupling Reactions: A Powerful Tool for the Synthesis of Agrochemicals

Journal of Agricultural and Food Chemistry, Journal Year: 2018, Volume and Issue: 66(34), P. 8914 - 8934

Published: July 31, 2018

Pd-catalyzed cross-coupling reactions have become essential tools for the construction of carbon–carbon and carbon–heteroatom bonds. Over last three decades, great efforts been made with chemistry in discovery, development, commercialization innovative new pharmaceuticals agrochemicals (mainly herbicides, fungicides, insecticides). In view growing interest both modern crop protection chemistry, this review gives a comprehensive overview successful applications various methodologies, which implemented as key steps synthesis (on R&D pilot-plant scales) such Heck, Suzuki, Sonogashira, Stille, Negishi reactions, well decarboxylative, carbonylative, α-arylative, carbon–nitrogen bond bond-forming reactions. Some perspectives challenges these catalytic coupling processes discovery are briefly discussed final section. The examples chosen demonstrate that approaches open-up new, low-cost, more efficient industrial routes to existing agrochemicals, methods also capability lead generation pesticides novel modes action sustainable protection.

Language: Английский

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