3d Transition Metals for C–H Activation

Chemical Reviews, Год журнала: 2018, Номер 119(4), С. 2192 - 2452

Опубликована: Ноя. 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.

Язык: Английский

---

Bidentate Directing Groups: An Efficient Tool in C–H Bond Functionalization Chemistry for the Expedient Construction of C–C Bonds

Chemical Reviews, Год журнала: 2020, Номер 120(3), С. 1788 - 1887

Опубликована: Янв. 6, 2020

During the past decades, synthetic organic chemistry discovered that directing group assisted C–H activation is a key tool for expedient and siteselective construction of C–C bonds. Among various strategies, bidentate groups are now recognized as one most efficient devices selective functionalization certain positions due to fact its metal center permits fine, tunable, reversible coordination. The family permit types assistance be achieved, such N,N-dentate, N,O-dentate, N,S-dentate auxiliaries, which categorized based on coordination site. In this review, we broadly discuss bond reactions formation bonds with aid groups.

Язык: Английский

---

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

Advanced Synthesis & Catalysis, Год журнала: 2017, Номер 359(8), С. 1245 - 1262

Опубликована: Март 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

Язык: Английский

---

Transition-Metal-Catalyzed, Coordination-Assisted Functionalization of Nonactivated C(sp³)–H Bonds

Chemical Reviews, Год журнала: 2021, Номер 121(24), С. 14957 - 15074

Опубликована: Окт. 29, 2021

Transition-metal-catalyzed, coordination-assisted C(sp3)–H functionalization has revolutionized synthetic planning over the past few decades as use of these directing groups allowed for increased access to many strategic positions in organic molecules. Nonetheless, several challenges remain preeminent, such requirement high temperatures, difficulty removing or converting groups, and, although metals provide some reactivity, employing outside palladium. This review aims give a comprehensive overview coordination-assisted, transition-metal-catalyzed, direct nonactivated bonds by covering literature since 2004 order demonstrate current state-of-the-art methods well limitations. For clarity, this been divided into nine sections transition metal catalyst with subdivisions type bond formation. Synthetic applications and reaction mechanism are discussed where appropriate.

Язык: Английский

---

The Fluorination of C−H Bonds: Developments and Perspectives

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(42), С. 14824 - 14848

Опубликована: Фев. 13, 2019

Abstract This Review summarizes advances in fluorination by C(sp 2 )−H and 3 activation. Transition‐metal‐catalyzed approaches championed palladium have allowed the installation of a fluorine substituent at ) sites, exploiting reactivity high‐oxidation‐state transition‐metal fluoride complexes combined with use directing groups (some transient) to control site stereoselectivity. The large majority known methods employ electrophilic reagents, but combining nucleophilic source an oxidant appeared. External ligands proven be effective for directed weakly coordinating auxiliaries, thereby enabling over reactivity. Methods relying on formation radical intermediates are complementary transition‐metal‐catalyzed processes as they allow undirected fluorination. To date, C−H fluorinations mainly N−F reagents unique Mn III ‐catalyzed oxidative using has been developed. Overall, field late‐stage progressed much more slowly, state play explaining why 18 F‐fluorination is still its infancy.

Язык: Английский

---

Copper-Catalyzed Electrochemical C–H Amination of Arenes with Secondary Amines

Journal of the American Chemical Society, Год журнала: 2018, Номер 140(36), С. 11487 - 11494

Опубликована: Авг. 30, 2018

Electrochemical oxidation represents an environmentally friendly solution to conventional methods that require caustic stoichiometric chemical oxidants. However, C–H functionalizations merging transition-metal catalysis and electrochemical techniques are, date, largely confined the use of precious metals divided cells. Herein, we report first examples copper-catalyzed aminations arenes at room temperature using undivided cells, thereby providing a practical for construction arylamines. The n-Bu4NI as redox mediator is crucial this transformation. On basis mechanistic studies including kinetic profiles, isotope effects, cyclic voltammetric analyses, radical inhibition experiments, reaction appears proceed via single-electron-transfer (SET) process, high valent Cu(III) species likely involved. These findings provide new avenue transition-metal-catalyzed functionalization reactions mediators.

Язык: Английский

---

Transition Metal‐Catalyzed Enantioselective C−H Functionalization via Chiral Transient Directing Group Strategies

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(45), С. 19773 - 19786

Опубликована: Июль 20, 2020

Abstract Transition metal‐catalyzed enantioselective functionalization of C−H bond, the most abundant functionality in organic molecules, has emerged as an expedient synthetic approach to streamline synthesis complex chiral molecules. Despite significant progress, traditional directing group‐enabled strategies require additional steps for installation and removal groups from target molecule. The recently developed asymmetric using transient ( c TDGs) offers a promising alternative that can circumvent this obstacle therefore simplify process. In Minireview, we briefly discuss advent recent advances emerging concept, with emphasis on discussing creation various stereogenic centers developments TDGs. Applications natural product ligand derivatizations are also discussed. We hope Minireview will highlight great potential strategy help inspire further endeavors.

Язык: Английский

---

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

ACS Catalysis, Год журнала: 2017, Номер 7(4), С. 2821 - 2847

Опубликована: Март 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.

Язык: Английский

---

Catalytic alkylation of unactivated C(sp³)–H bonds for C(sp³)–C(sp³) bond formation

Chemical Society Reviews, Год журнала: 2019, Номер 48(18), С. 4921 - 4942

Опубликована: Янв. 1, 2019

This review summarizes recent advancements in catalytic direct transformation of unactivated C(sp³)–H bonds into C(sp³)–C(sp³) bonds.

Язык: Английский

---

Controlled functionalization ofo-carboraneviatransition metal catalyzed B–H activation

Chemical Society Reviews, Год журнала: 2019, Номер 48(13), С. 3660 - 3673

Опубликована: Янв. 1, 2019

This review summarizes recent advances in transition metal catalyzed vertex-specific BH functionalization ofo-carborane for controlled synthesis of its derivatives.

Язык: Английский

---