Cobalt/Salox‐Catalyzed Enantioselective C−H Functionalization of Arylphosphinamides

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(25)

Опубликована: Апрель 6, 2022

Previous methods on CoIII -catalyzed asymmetric C-H activation rely the use of tailor-made cyclopentadienyl-ligated complexes, which require lengthy steps for preparation. Herein, we report an unprecedented enantioselective functionalization enabled by a simple cobalt/salicyloxazoline (Salox) catalysis. The chiral Salox ligands can be easily prepared in one step from salicylonitrile and amino alcohols. A broad range P-stereogenic compounds were synthesized high yields with excellent enantioselectivities (45 examples, up to 99 % yield >99 ee). isolation characterization several intermediates provided insights into generation active catalytic cobalt species, action Salox, mode stereocontrol.

Язык: Английский

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Transition-metal-catalyzed C–H bond alkylation using olefins: recent advances and mechanistic aspects

Chemical Society Reviews, Год журнала: 2022, Номер 51(17), С. 7358 - 7426

Опубликована: Янв. 1, 2022

Transition metal catalysis has contributed immensely to C-C bond formation reactions over the last few decades, and alkylation is no exception. The superiority of such methodologies traditional evident from minimal reaction steps, shorter times, atom economy while also allowing control regio- stereo-selectivity. In particular, hydrocarbonation alkenes grabbed increased attention due its fundamental ability effectively selectively synthesise a wide range industrially pharmaceutically relevant moieties. This review attempts provide scientific viewpoint systematic analysis recent developments in transition-metal-catalyzed various C-H bonds using simple activated olefins. key features mechanistic studies involved these transformations are described briefly.

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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Atroposelective isoquinolinone synthesis through cobalt-catalysed C–H activation and annulation

Nature Synthesis, Год журнала: 2022, Номер 1(9), С. 709 - 718

Опубликована: Июль 18, 2022

Язык: Английский

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Single‐Step Synthesis of Atropisomers with Vicinal C−C and C−N Diaxes by Cobalt‐Catalyzed Atroposelective C−H Annulation

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(39)

Опубликована: Авг. 2, 2022

The atroposelective synthesis of atropisomers with vicinal diaxes remains rare and challenging, due to the steric influence between two axes their unique topology. Herein, we disclose a single-step construction C-C C-N chiral by cyclopentadiene (Cp)-free cobalt-catalyzed intramolecular C-H annulation, providing desired diaxial structures decent stereocontrols both (up >99 % ee 70 : 1 dr). optically pure products bearing fluorophores show circular polarized luminescence (CPL) properties, being candidate materials for potential CPL applications. Atropisomerization experiments density function theory (DFT) calculations are conducted study rotational barriers rotation pathways diaxes.

Язык: Английский

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Cobalt(III)/Chiral Carboxylic Acid‐Catalyzed Enantioselective Synthesis of Benzothiadiazine‐1‐oxides via C−H Activation

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(28)

Опубликована: Май 2, 2022

Abstract Among sulfoximine derivatives containing a chiral sulfur center, benzothiadiazine‐1‐oxides are important for applications in medicinal chemistry. Here, we report that the combination of an achiral cobalt(III) catalyst and pseudo‐ C 2 ‐symmetric H 8 ‐binaphthyl carboxylic acid enables asymmetric synthesis from sulfoximines dioxazolones via enantioselective C−H bond cleavage. With optimized protocol, with several functional groups can be accessed high enantioselectivity.

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 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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Electrooxidative Rhodium(III)/Chiral Carboxylic Acid‐Catalyzed Enantioselective C−H Annulation of Sulfoximines with Alkynes

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(15)

Опубликована: Янв. 30, 2024

Abstract The combination of achiral Cp*Rh(III) with chiral carboxylic acids (CCAs) represents an efficient catalytic system in transition metal‐catalyzed enantioselective C−H activation. However, this hybrid catalysis is limited to redox‐neutral activation reactions and the adopt oxidative remains elusive pose a significant challenge. Herein, we describe development electrochemical Cp*Rh(III)‐catalyzed annulation sulfoximines alkynes enabled by acid (CCA) operationally friendly undivided cell at room temperature. A broad range enantioenriched 1,2‐benzothiazines are obtained high yields excellent enantioselectivities (up 99 % yield 98 : 2 er). practicality method demonstrated scale‐up reaction batch reactor external circulation. crucial intermediate isolated, characterized, transformed, providing rational support for Rh(III)/Rh(I) electrocatalytic cycle.

Язык: Английский

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