Transition metal-catalyzed C–H bond functionalizations by the use of diverse directing groups

Organic Chemistry Frontiers, Journal Year: 2015, Volume and Issue: 2(9), P. 1107 - 1295

Published: Jan. 1, 2015

In this review, a summary of transition metal-catalyzed C–H activation by utilizing the functionalities as directing groups is presented.

Language: Английский

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Transition-Metal-Catalyzed Cross-Couplings through Carbene Migratory Insertion

Chemical Reviews, Journal Year: 2017, Volume and Issue: 117(23), P. 13810 - 13889

Published: Nov. 1, 2017

Transition-metal-catalyzed cross-coupling reactions have been well-established as indispensable tools in modern organic synthesis. One of the major research goals area is expanding scope coupling partners. In past decade, diazo compounds (or their precursors N-tosylhydrazones) emerged nucleophilic partners C-C single bond or C═C double formations transition-metal-catalyzed reactions. This type reaction involves following general steps. First, organometallic species generated by various processes, including oxidative addition, transmetalation, cyclization, cleavage, and C-H activation. Subsequently, reacts with substrate to generate metal carbene intermediate, which undergoes rapid migratory insertion form a bond. The new from may undergo transformations. carbene-based has proven be general: transition metals Pd, Cu, Rh, Ni, Co, Ir are effective catalysts; also extended substrates other than compounds; cascade processes devised based on insertion. review will summarize achievements made this field since 2001.

Language: Английский

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Formal S_N‐Type Reactions in Rhodium(III)‐Catalyzed CH Bond Activation

Advanced Synthesis & Catalysis, Journal Year: 2014, Volume and Issue: 356(7), P. 1443 - 1460

Published: May 5, 2014

Abstract (Pentamethylcyclopentadienyl)rhodium (RhCp*)‐catalyzed CH transformations have emerged as a prosperous field in bond activation. Recent advances this area significantly focused on the development of new strategies for CC and Cheteroatom formation that are characterized by novel reactivity RhCp* catalyst to undergo formal S N ‐type reactions with electrophilic substrates. This review is intended give an overview rather class RhCp*‐catalyzed transformations, covering recent bond‐forming reactions. The nature reaction partner these functionalization serves guideline throughout article and, combined selected descriptions mechanistic proposals, should emphasize general characteristics within class. magnified image

Language: Английский

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Transition metal-catalyzed C–H functionalization of N-oxyenamine internal oxidants

Chemical Society Reviews, Journal Year: 2014, Volume and Issue: 44(5), P. 1155 - 1171

Published: Nov. 24, 2014

The N-oxyenamine internal oxidant gives more chance to investigate the C–H bond activation under mild reaction conditions.

Language: Английский

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Rhodium‐Catalyzed C(sp²)‐ or C(sp³)−H Bond Functionalization Assisted by Removable Directing Groups

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(25), P. 8304 - 8329

Published: Oct. 12, 2018

Abstract In recent years, transition‐metal‐catalyzed C−H activation has become a key strategy in the field of organic synthesis. Rhodium complexes are widely used as catalysts variety functionalization reactions because their high reactivity and selectivity. The availability number rhodium various oxidation states enables diverse reaction patterns to be obtained. Regioselectivity, an important issue chemistry, can accomplished by using directing group assist reaction. However, obtain target functionalized compounds, it is also necessary use that easily removed. A wide range directed catalyzed have been reported date. this Review, we discuss Rh‐catalyzed aided removable such phenol, amine, aldehyde, ketones, ester, acid, sulfonic N‐heteroaromatic derivatives.

Language: Английский

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Recent progress on donor and donor–donor carbenes

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 49(3), P. 908 - 950

Published: Jan. 1, 2020

This review highlights the recent advances in donor and donor–donor carbenes.

Language: Английский

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Rhodium-Catalyzed C–H Activation of Phenacyl Ammonium Salts Assisted by an Oxidizing C–N Bond: A Combination of Experimental and Theoretical Studies

Journal of the American Chemical Society, Journal Year: 2015, Volume and Issue: 137(4), P. 1623 - 1631

Published: Jan. 8, 2015

Rh(III)-catalyzed C–H activation assisted by an oxidizing directing group has evolved to a mild and redox-economic strategy for the construction of heterocycles. Despite success, these coupling systems are currently limited cleavage N–O or N–N bond. Cleavage C–N bond, which allows complementary carbocycle synthesis, is unprecedented. In this article, α-ammonium acetophenones with bond have been designed as substrates under redox-neutral conditions. The α-diazo esters afforded benzocyclopentanones, unactivated alkenes such styrenes aliphatic olefins gave ortho-olefinated acetophenoes. both reactions proceeded broad scope, high efficiency, functional tolerance. Moreover, efficient one-pot diazo realized starting from α-bromoacetophenones triethylamine. reaction mechanism studied combination experimental theoretical methods. particular, three distinct mechanistic pathways scrutinized DFT studies, revealed that occurs via C-bound enolate-assisted concerted metalation–deprotonation rate-limiting. subsequent C–C formation steps, lowest energy pathway involves two rhodium carbene species key intermediates.

Language: Английский

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Cobalt(III)‐Catalyzed Directed CH Coupling with Diazo Compounds: Straightforward Access towards Extended π‐Systems

Angewandte Chemie International Edition, Journal Year: 2015, Volume and Issue: 54(15), P. 4508 - 4511

Published: Feb. 20, 2015

The first highly efficient and scalable cobalt-catalyzed directed C-H functionalization with carbene precursors is presented. This methodology provides a modular route towards new class of conjugated polycyclic hydrocarbons tunable emission wavelengths both in solution the solid state.

Language: Английский

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New Approaches to the Synthesis of Metal Carbenes

Angewandte Chemie International Edition, Journal Year: 2016, Volume and Issue: 55(32), P. 9134 - 9166

Published: June 16, 2016

Abstract Metal carbenes usually possess versatile reactivities that are controlled by the presence of both metals and ligands. Diazo compounds commonly used for generation such species through elimination nitrogen. However, they often unstable, explosive, toxic, which limits their applications in large‐scale syntheses. Thus, identifying sustainable safe surrogates metal has attracted great attention. In this Review, we summarize some most important breakthroughs generation, catalytic reactions, selectivity control from non‐diazo starting compounds.

Language: Английский

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Asymmetric Synthesis of Isoindolones by Chiral Cyclopentadienyl‐Rhodium(III)‐Catalyzed CH Functionalizations

Angewandte Chemie International Edition, Journal Year: 2014, Volume and Issue: 53(30), P. 7896 - 7899

Published: June 10, 2014

Directed Cp*Rh(III)-catalyzed carbon-hydrogen (C-H) bond functionalizations have evolved as a powerful strategy for the construction of heterocycles. Despite their high value, development related asymmetric reactions is largely lagging behind due to limited availability robust and tunable chiral cyclopentadienyl ligands. Rhodium complexes comprising Cp ligand with an atropchiral biaryl backbone enables synthesis isoindolones from arylhydroxamates weakly alkyl donor/acceptor diazo derivatives one-carbon component under mild conditions. The complex guides substrates double facial selectivity yielding in good yields excellent enantioselectivities.

Language: Английский

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