3d Transition Metals for C–H Activation

Chemical Reviews, Journal Year: 2018, Volume and Issue: 119(4), P. 2192 - 2452

Published: Nov. 27, 2018

C–H activation has surfaced as an increasingly powerful tool for molecular sciences, with notable applications to material crop protection, drug discovery, and pharmaceutical industries, among others. Despite major advances, the vast majority of these functionalizations required precious 4d or 5d transition metal catalysts. Given cost-effective sustainable nature earth-abundant first row metals, development less toxic, inexpensive 3d catalysts gained considerable recent momentum a significantly more environmentally-benign economically-attractive alternative. Herein, we provide comprehensive overview on until summer 2018.

Language: Английский

---

A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

Chemical Society Reviews, Journal Year: 2018, Volume and Issue: 47(17), P. 6603 - 6743

Published: Jan. 1, 2018

The present review is devoted to summarizing the recent advances (2015-2017) in field of metal-catalysed group-directed C-H functionalisation. In order clearly showcase molecular diversity that can now be accessed by means directed functionalisation, whole organized following directing groups installed on a substrate. Its aim comprehensive reference work, where specific group easily found, together with transformations which have been carried out it. Hence, primary format this schemes accompanied concise explanatory text, are ordered sections according their chemical structure. feature typical substrates used, products obtained as well required reaction conditions. Importantly, each example commented respect most important positive features and drawbacks, aspects such selectivity, substrate scope, conditions, removal, greenness. targeted readership both experts functionalisation chemistry (to provide overview progress made last years) and, even more so, all organic chemists who want introduce way thinking for design straightforward, efficient step-economic synthetic routes towards molecules interest them. Accordingly, should particular also scientists from industrial R&D sector. overall goal promote application reactions outside research dedicated method development establishing it valuable archetype contemporary R&D, comparable role cross-coupling play date.

Language: Английский

---

(Pentamethylcyclopentadienyl)cobalt(III)‐Catalyzed C–H Bond Functionalization: From Discovery to Unique Reactivity and Selectivity

Advanced Synthesis & Catalysis, Journal Year: 2017, Volume and Issue: 359(8), P. 1245 - 1262

Published: March 16, 2017

Abstract High‐valent (pentamethylcyclopentadienyl)cobalt(III) [Cp*Co(III)] catalysts were found as inexpensive alternatives to (pentamethylcyclopentadienyl)rhodium(III) [Cp*Rh(III)] in the field of C—H bond functionalization, and applied a variety transformations. In this review, after discovery early examples Cp*Co(III)‐catalyzed functionalization are summarized, unique reactivity selectivity Cp*Co(III) differences between cobalt rhodium catalysis intensively discussed. Such assumed be caused by lower electronegativity, hard nature, smaller ionic radius cobalt. magnified image

Language: Английский

---

Transition metal-catalysed couplings between arenes and strained or reactive rings: combination of C–H activation and ring scission

Chemical Society Reviews, Journal Year: 2016, Volume and Issue: 45(23), P. 6462 - 6477

Published: Jan. 1, 2016

Transition metal-catalysed systems of C–H activation arenes in combination with opening strained or reactive three, four, and five membered rings are summarized this review.

Language: Английский

---

Recent Advances in Catalytic C(sp²)–H Allylation Reactions

ACS Catalysis, Journal Year: 2017, Volume and Issue: 7(4), P. 2821 - 2847

Published: March 14, 2017

The linear or branched allyl moieties on aromatic rings are well-known as ubiquitous structural motifs found in a range of natural products and medicinally relevant molecules. They also represent an important class organic intermediates for the transformation olefin group into many useful functional groups. Established methods installation allylic groups rely primarily nucleophilic substitution transmetalation aryl metal complexes to electrophiles, Lewis acid-mediated Friedel–Crafts allylation electron-rich arenes, Tsuji–Trost reactions with π-allyl species. Complementing previous protocols, transition metal-catalyzed via C–H activation strategy using various surrogates like acetates, carbonates, phosphonates, halides, alcohols, vinyl oxiranes, allenes, 1,3-dienes, others have recently emerged powerful tool creating corresponding allyl, crotyl prenyl moieties. This review, which includes all reported literature until beginning 2017, focuses recent progress direct vinylic C(sp2)–H bonds sources catalysts.

Language: Английский

---

Full Selectivity Control in Cobalt(III)‐Catalyzed C−H Alkylations by Switching of the C−H Activation Mechanism

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(35), P. 10378 - 10382

Published: June 21, 2017

Selectivity control in hydroarylation-based C-H alkylation has been dominated by steric interactions. A conceptually distinct strategy that exploits the programmed switch activation mechanism means of cobalt catalysis is presented, which sets stage for convenient alkylations with unactivated alkenes. Detailed mechanistic studies provide compelling evidence a programmable from linear-selective ligand-to-ligand hydrogen transfer to branched-selective base-assisted internal electrophilic-type substitution.

Language: Английский

---

C–H functionalization by high-valent Cp*Co(iii) catalysis

Chemical Communications, Journal Year: 2017, Volume and Issue: 53(22), P. 3165 - 3180

Published: Jan. 1, 2017

Significant progress has been accomplished in directed C–H functionalization through the use of earth-abundant and inexpensive first-row transition metals.

Language: Английский

---

Enantioselective Cobalt(III)‐Catalyzed C−H Activation Enabled by Chiral Carboxylic Acid Cooperation

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(47), P. 15425 - 15429

Published: Oct. 6, 2018

The enantioselective cobalt(III)-catalyzed C-H alkylation was achieved through the design of a novel chiral acid. activation characterized by high position-, regio- and enantio-control under exceedingly mild reaction conditions. Thereby, robust cooperative cobalt(III) catalysis proved tolerant valuable electrophilic functional groups, including hydroxyl, bromo, iodo substituents. Mechanistic studies revealed considerable additive effect on kinetics negative non-linear-effect.

Language: Английский

---

Cobalt‐Catalyzed C−H Thiolation through Dehydrogenative Cross‐Coupling

Angewandte Chemie International Edition, Journal Year: 2016, Volume and Issue: 55(37), P. 11287 - 11291

Published: July 20, 2016

Abstract A cobalt‐catalyzed dehydrogenative cross‐coupling of thiols and indoles is reported. Using a cooperative reaction system, new mode action for the C−heteroatom bond formation was found. The directed C−H activation catalysis overrides an undirected thiolation indole in 3‐position that occurs absence cobalt. Mechanistic studies indicate sequence activation, thiolate transfer, reductive elimination.

Language: Английский

---

Direct Functionalization of C−H Bonds by Iron, Nickel, and Cobalt Catalysis

Chemistry - A European Journal, Journal Year: 2017, Volume and Issue: 23(39), P. 9206 - 9232

Published: June 7, 2017

Abstract Non‐precious‐metal‐catalyzed reactions are of increasing importance in chemistry due to the outstanding ecological and economic properties these metals. In subfield metal‐catalyzed direct C−H functionalization reactions, recent years have shown an number publications dedicated this topic. Nickel, cobalt, last but not least iron, started enter a field which was long dominated by precious metals such as palladium, rhodium, ruthenium, iridium. The present review article summarizes development iron‐, nickel‐, cobalt‐catalyzed until end 2016, discusses scope limitations transformations.

Language: Английский

---