Rhodium-Catalyzed Asymmetric C–H Functionalization Reactions

Chemical Reviews, Год журнала: 2023, Номер 123(16), С. 10079 - 10134

Опубликована: Авг. 1, 2023

This review summarizes the advancements in rhodium-catalyzed asymmetric C–H functionalization reactions during last two decades. Parallel to rapidly developed palladium catalysis, rhodium catalysis has attracted extensive attention because of its unique reactivity and selectivity reactions. In recent years, Rh-catalyzed have been significantly many respects, including catalyst design, reaction development, mechanistic investigation, application synthesis complex functional molecules. presents an explicit outline catalysts ligands, mechanism, scope coupling reagents, applications.

Язык: Английский

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Enantio‐ and Regioselective Electrooxidative Cobalt‐Catalyzed C−H/N−H Annulation with Alkenes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(11)

Опубликована: Янв. 20, 2023

In recent years, the merging of electrosynthesis with 3d metal catalyzed C-H activation has emerged as a sustainable and powerful technique in organic synthesis. Despite impressive advantages, development an enantioselective version remains elusive poses daunting challenge. Herein, we report first electrooxidative cobalt-catalyzed enantio- regioselective C-H/N-H annulation olefins using undivided cell at room temperature (up to 99 % ee). t Bu-Salox, rationally designed Salox ligand bearing bulky tert-butyl group ortho-position phenol, was found be crucial for this asymmetric reaction. A strong cooperative effect between Bu-Salox 3,4,5-trichloropyridine enabled highly more challenging α-olefins without secondary bond interactions 96 ee 97 : 3 rr). Cyclovoltametric studies, preparation, characterization, transformation cobaltacycle intermediates shed light on mechanism

Язык: Английский

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Base‐Promoted Electrochemical Co^II‐catalyzed Enantioselective C−H Oxygenation

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(21)

Опубликована: Март 20, 2023

Metalla-electrocatalyzed C-H oxygenation represents one of the most straightforward and sustainable approaches to access valuable oxygenated molecules. Despite significant advances, development enantioselective electrochemical reaction is very challenging remains elusive. Herein, we described first CoII -catalyzed alkoxylation. A broad range enantioenriched alkoxylated phosphinamides were obtained in good yields with excellent enantioselectivities (up 98 % yield >99 ee). An unusual cobalt(III) alcohol complex was prepared fully characterized, which proven be a key intermediate this alkoxylation reaction. Mechanistic studies revealed that oxidation CoIII CoIV facilitated by base whole process proceeded through cobalt(III/IV/II) catalytic cycle.

Язык: Английский

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Cobalt-catalyzed atroposelective C−H activation/annulation to access N−N axially chiral frameworks

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Авг. 29, 2023

The N-N atropisomer, as an important and intriguing chiral system, was widely present in natural products, pharmaceutical lead compounds, advanced material skeletons. anisotropic structural characteristics caused by its special axial rotation have always been one of the challenges that chemists strive to overcome. Herein, we report efficient method for enantioselective synthesis axially frameworks via a cobalt-catalyzed atroposelective C-H activation/annulation process. reaction proceeds under mild conditions using Co(OAc)2·4H2O catalyst with salicyl-oxazoline (Salox) ligand O2 oxidant, affording variety products high yields enantioselectivities. This protocol provides approach facile construction atropisomers further expands range derivatives. Additionally, electrocatalysis, desired were also successfully achieved good excellent efficiencies

Язык: Английский

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Cobalt-Catalyzed Enantioselective C–H Annulation with Alkenes

ACS Catalysis, Год журнала: 2023, Номер 13(7), С. 4250 - 4260

Опубликована: Март 13, 2023

Herein, we disclose an efficient cobalt-catalyzed enantioselective C–H activation and annulation of benzamides with alkenes. This transformation is facilitated via the commercially available cobalt(II) catalyst in presence easily prepared chiral salicyl-oxazoline (Salox) ligand, which provides facile access to (R) or (S) enantiomers dihydroisoquinolone derivatives. It noticeable that reaction proceeded efficiently within extremely short time from 10 30 min under mild conditions. A broad range alkenes bear various functional substituents have been shown good compatibility deliver targeted products high yields enantioselectivities (51 examples, up 98% yield 99% ee). The gram scale experiment removal directing group further demonstrate practicability this protocol potential industrial applications. Density theory calculations elucidate mechanism, spin-state change olefin insertion step accelerates subsequent C–N reductive elimination, identified as stereo-determining step. AIM analysis indicates π interactions are vital for controlling switching stereoselectivity.

Язык: Английский

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Cobalt‐Catalyzed Enantioselective C−H Carbonylation towards Chiral Isoindolinones

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(10)

Опубликована: Янв. 11, 2024

Transition metal-catalyzed enantioselective C-H carbonylation with carbon monoxide, an essential and easily available C1 feedstock, remains challenging. Here, we disclosed unprecedented catalyzed by inexpensive readily cobalt(II) salt. The reactions proceed efficiently through desymmetrization, kinetic resolution, parallel affording a broad range of chiral isoindolinones in good yields excellent enantioselectivities (up to 92 % yield 99 ee). synthetic potential this method was demonstrated asymmetric synthesis biological active compounds, such as (S)-PD172938 (S)-Pazinaclone. resulting also serve ligands cobalt-catalyzed annulation alkynes construct phosphorus stereocenter.

Язык: Английский

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Cobalt(III)-Catalyzed Enantioselective C–H Functionalization: Ligand Innovation and Reaction Development

Accounts of Chemical Research, Год журнала: 2025, Номер unknown

Опубликована: Фев. 26, 2025

ConspectusIn contrast to precious transition metals, such as palladium and rhodium, the development of novel chiral ligands for enantioselective C-H functionalizations catalyzed by earth-abundant, cost-effective, environmentally friendly 3d metals poses substantial challenges, primarily due variable oxidation states, intricate coordination patterns, limited mechanistic insights. In this Account, we summarize our research endeavors in three types Co(III) catalysis: pseudotetrahedral achiral Cp*Co(III)/chiral carbonyl acid (CCA) catalysis, situ-generated octahedral cobalt(III) via cobalt/salicyloxazoline (Salox) Co(II)/chiral phosphoric (CPA) cooperative achieved through strategic ligand design. Our initial objective was achieve functionalization Cp*Co(III) catalysts with external ligands, aiming circumvent laborious preparation CpxCo(III) complexes. To end, developed several CCA incorporating non-covalent interactions (NCIs) a crucial design element. Next, address limitations associated lengthy synthesis Cp-ligated complexes difficulties modification, explored concept situ generation catalysis using commercially available cobalt(II) salts tailor-made ligands. This exploration led two innovative catalytic systems, namely, Co(II)/Salox Co(II)/CCA sequential catalysis. The emerged versatile strategy, demonstrating excellent enantioselectivities across range asymmetric reactions construct various molecules central, axial, planar, inherent chirality. facile single step, along ease further enhances versatility applicability approach. Moreover, successfully applied cobalt/Salox electro- photochemical-catalyzed functionalization, electrons or oxygen traceless oxidant, thereby eliminating need stoichiometric chemical oxidants. Through studies reaction developments, elucidated detailed structure-enantioselectivity relationships which are expected inform future endeavors. Finally, Co(II)/CPA enabled spiro-γ-lactams olefination/asymmetric [4 + 1] spirocyclization. Mechanistically, establishment stereochemistry occurs during cyclization where CPA serves both neutral Brønsted acid, stereoinduction independent cleavage step. We anticipate that insights advancements Account will inspire innovations drive progress metal-catalyzed reactions.

Язык: Английский

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Cobalt-catalyzed enantioselective C–H/N–H annulation of aryl sulfonamides with allenes or alkynes: facile access to C–N axially chiral sultams

Chemical Science, Год журнала: 2023, Номер 14(26), С. 7291 - 7303

Опубликована: Янв. 1, 2023

Herein we report a cobalt-catalyzed enantioselective C-H/N-H annulation of aryl sulfonamides with allenes and alkynes, using either chemical or electrochemical oxidation. By O2 as the oxidant, proceeds efficiently low catalyst/ligand loading 5 mol% tolerates wide range allenes, including 2,3-butadienoate, allenylphosphonate, phenylallene, resulting in C-N axially chiral sultams high enantio-, regio-, position selectivities. The alkynes also exhibits excellent enantiocontrol (up to >99% ee) variety functional sulfonamides, internal terminal alkynes. Furthermore, oxidative is achieved simple undivided cell, demonstrating versatility robustness cobalt/Salox system. gram-scale synthesis asymmetric catalysis further highlight practical utility this method.

Язык: Английский

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Cobalt(III)-catalyzed asymmetric ring-opening of 7-oxabenzonorbornadienes via indole C–H functionalization

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Фев. 25, 2023

Abstract Asymmetric ring-opening of 7-oxabenzonorbornadienes is achieved via Co-catalyzed indole C–H functionalization. The utilization chiral Co-catalyst consisting a binaphthyl-derived trisubstituted cyclopentadienyl ligand resulted in high yields (up to 99%) and excellent enantioselectivity (>99% ee) for the target products with tolerance diverse functional groups. Opposite diastereoselectivities are obtained or Cp*CoI 2 CO. Combined experimental computational studies suggest β -oxygen elimination being selectivity-determining step reaction. Meanwhile, reactions 7-azabenzonorbornadiene could also be executed diastereodivergent manner.

Язык: Английский

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Synthesis of Axially Chiral Biaryls through Cobalt(II)‐Catalyzed Atroposelective C−H Arylation

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(40)

Опубликована: Авг. 16, 2023

Highly efficient synthesis of axially chiral biaryl amines through cobalt-catalyzed atroposelective C-H arylation using easily accessible cobalt(II) salt and salicyloxazoline ligand has been reported. This methodology provides a straightforward sustainable access to broad range enantioenriched biaryl-2-amines in good yields (up 99 %) with excellent enantioselectivities % ee). The synthetic utility the unprecedented method is highlighted by its scalability diverse transformations.

Язык: Английский

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