Transient Directing Groups for Transformative C–H Activation by Synergistic Metal Catalysis

Chem, Journal Year: 2017, Volume and Issue: 4(2), P. 199 - 222

Published: Dec. 21, 2017

Language: Английский

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Beyond C2 and C3: Transition-Metal-Catalyzed C–H Functionalization of Indole

ACS Catalysis, Journal Year: 2017, Volume and Issue: 7(9), P. 5618 - 5627

Published: July 11, 2017

The indole scaffold will continue to play a vital part in the future of drug discovery and agrochemical development. Because this, necessity for elegant techniques enable selective C–H functionalization is vast. Early developments have led primarily C2 C3 because inherent reactivity pyrrole ring. Despite methods been developed on benzenoid moiety at C4, C5, C6, C7. This review focuses contributions made indoles other related heteroaromatics such as carbazoles.

Language: Английский

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Electronic and Steric Tuning of a Prototypical Piano Stool Complex: Rh(III) Catalysis for C–H Functionalization

Accounts of Chemical Research, Journal Year: 2017, Volume and Issue: 51(1), P. 170 - 180

Published: Dec. 22, 2017

ConspectusThe history of transition metal catalysis is heavily steeped in ligand design, clearly demonstrating the importance this approach. The intimate relationship between and can profoundly affect outcome a reaction, often impacting selectivity, physical properties, lifetime catalyst. Importantly, metal–ligand provide near limitless opportunities for reaction discovery. Over past several years, transition-metal-catalyzed C–H bond functionalization reactions have been established as critical foundation organic chemistry that provides new forming strategies. Among d-block elements, palladium arguably one most popular metals to accomplish such transformations. One possible explanation achievement could be broad set phosphine amine based ligands available chemist's toolbox compatible with palladium. In parallel, other investigated functionalization. them, pentamethylcyclopentadienyl (Cp*) Rh(III) complexes emerged powerful mode transformations providing spectrum reactivity. This approach possesses advantage very low catalyst loading, are typically performed under mild conditions allowing functional group tolerance. Cp*Rh(III) considered privileged plethora involving cleavage event developed. search alternative cyclopentadienyl has eclipsed by tremendous effort devoted exploring considerable scope catalyzed complexes, despite potential strategy enabling Thus, modification efforts an exception research directed toward rhodium catalysts sparse. Recently, chiral appeared enantioselective Rh(III)-catalyzed performed. Alongside ligands, equally important collection achiral cyclopentadienyl-derived also emerged. design already translated significant success solving inherent problems reactivity selectivity encountered throughout development Account describes evolution skeletons Rh(III)-catalysis since introduction present. Specific emphasis placed on synthetic applications achieved mono-, di-, or pentasubstituted exhibiting stunning effect selectivity. Furthermore, underlying question when dealing strategies explain reason outperforms another. Conjecture speculation abound, but extensive characterization their steric electronic properties carried out information about all contribute our understanding give crucial pieces solve puzzle.

Language: Английский

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Increasing Catalyst Efficiency in C−H Activation Catalysis

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 57(9), P. 2296 - 2306

Published: Dec. 5, 2017

Abstract C−H activation reactions with high catalyst turnover numbers are still very rare in the literature and 10 mol % is a common loading this field. We offer representative overview of efficient catalysis to highlight neglected aspect development inspire future effort towards more activation. Examples ranging from palladium catalysis, Cp*Rh III ‐ Cp*Co ‐catalysis, borylation silylation methane presented. In these reactions, up tens thousands turnovers have been observed.

Language: Английский

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Recent Advances in Ruthenium(II)‐Catalyzed C−H Bond Activation and Alkyne Annulation Reactions

Advanced Synthesis & Catalysis, Journal Year: 2018, Volume and Issue: 361(4), P. 654 - 672

Published: Aug. 20, 2018

Abstract In the last few decades, transition metal‐catalyzed activation of inert C−H bonds has led to a fundamental change in field synthetic chemistry. Most these reactions deal with simple functionalizations or additions. However, recent years have witnessed an increase bond and annulation reactions. These are appealing organic chemist as they afford highly valuable cyclic compounds rapid sustainable manner from readily available compounds. This review article attempts highlight advances ruthenium alkyne magnified image

Language: Английский

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Ruthenium-Catalyzed Electrochemical Dehydrogenative Alkyne Annulation

ACS Catalysis, Journal Year: 2018, Volume and Issue: 8(5), P. 3820 - 3824

Published: March 9, 2018

A ruthenium-catalyzed electrochemical dehydrogenative annulation reaction of aniline derivatives and alkynes has been developed for the synthesis indoles. Electric current is used to recycle active ruthenium-based catalyst promote H2 evolution. The electrolysis operationally convenient as it employs a simple undivided cell, proceeds efficiently in an aqueous solution, insensitive air.

Language: Английский

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Electrooxidative Ruthenium‐Catalyzed C−H/O−H Annulation by Weak O‐Coordination

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(20), P. 5818 - 5822

Published: March 31, 2018

Electrocatalysis has been identified as a powerful strategy for organometallic catalysis, and yet electrocatalytic C-H activation is restricted to strongly N-coordinating directing groups. The first example of by weak O-coordination presented, in which versatile ruthenium(II) carboxylate catalyst enables electrooxidative C-H/O-H functionalization alkyne annulations the absence metal oxidants; thereby exploiting sustainable electricity sole oxidant. Mechanistic insights provide strong support facile ruthenation an effective electrochemical reoxidation key ruthenium(0) intermediate.

Language: Английский

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Carbon–Carbon Bond Cleavage for Late-Stage Functionalization

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(22), P. 12313 - 12370

Published: Nov. 9, 2023

Late-stage functionalization (LSF) introduces functional group or structural modification at the final stage of synthesis natural products, drugs, and complex compounds. It is anticipated that late-stage would improve drug discovery's effectiveness efficiency hasten creation various chemical libraries. Consequently, products a productive technique to produce product derivatives, which significantly impacts biology development. Carbon-carbon bonds make up fundamental framework organic molecules. Compared with carbon-carbon bond construction, activation can directly enable molecular editing (deletion, insertion, atoms groups atoms) provide more efficient accurate synthetic strategy. However, selective unstrained still one most challenging projects in synthesis. This review encompasses strategies employed recent years for cleavage by explicitly focusing on their applicability functionalization. expands current discourse reactions providing comprehensive overview types bonds. includes C-C(sp), C-C(sp2), C-C(sp3) single bonds; double triple bonds, focus catalysis transition metals organocatalysts. Additionally, specific topics, such as ring-opening processes involving three-, four-, five-, six-membered rings, are discussed, exemplar applications these techniques showcased context bioactive molecules discovery. aims shed light advancements field propose potential avenues future research realm

Language: Английский

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Enantioselective [3+2] Annulation of Aldimines with Alkynes by Scandium‐Catalyzed C−H Activation

Angewandte Chemie International Edition, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 3, 2025

Abstract The enantioselective [3+2] annulation of readily accessible aldimines with alkynes via C−H activation is, in principle, a straightforward and atom‐efficient route for synthesizing chiral 1‐aminoindenes, which are important components wide array natural products, bioactive molecules, functional materials. However, such asymmetric transformation has remained undeveloped to date due the lack suitable catalysts. Here, we report first time using half‐sandwich scandium This protocol enabled synthesis diverse multi‐substituted 1‐aminoindene derivatives 100 % atom‐efficiency, broad substrate scope, high regio‐ enantioselectivity. Density theory (DFT) analyses have revealed that noncovalent C−H⋅⋅⋅π interaction between tert ‐Bu substituent cyclopentadienyl (Cp) ligand phenyl ring an aromatic aldimine played role achieving level work not only offers efficient selective new family but also unprecedented insights into enantioselectivity control Cp‐ligated metal

Language: Английский

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Cobalt‐Catalyzed Annulation Reactions via C−H Bond Activation

ChemCatChem, Journal Year: 2017, Volume and Issue: 10(4), P. 683 - 705

Published: Nov. 1, 2017

Abstract Considerable research attention has been directed towards the use of first‐row transition metals in organic synthesis. The more abundant, and less expensive cobalt is considered to be an effective alternative for second third‐row noble metals, especially C−H bond functionalization reactions. In this Minireview, we will summarize features, recent achievements Co‐catalyzed directing group assisted activation/cyclization reactions their mechanistic insights.

Language: Английский

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