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

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Aug. 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

Language: Английский

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Dual-Catalyzed Stereodivergent Electrooxidative Homocoupling of Benzoxazolyl Acetate

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(2), P. 1522 - 1531

Published: Jan. 3, 2024

The development of a reliable strategy for stereodivergent radical reactions that allows convenient access to all stereoisomers homocoupling adducts with multiple stereogenic centers remains an unmet goal in organic synthesis. Herein, we describe dual-catalyzed electrooxidative C(sp3)–H/C(sp3)–H complete absolute and relative stereocontrol the synthesis molecules contiguous quaternary stereocenters general predictable manner. reaction is achieved by synergistically utilizing two distinct chiral catalysts convert identical racemic substrates into inherently distinctive reactive intermediates, dictate enantioselective addition, allow full complement stereoisomeric products via simple catalyst permutation. successful execution dual-electrocatalytic programmed activation provides significant conceptual advantage will serve as useful foundation further research cooperative stereocontrolled transformations diversity-oriented

Language: Английский

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

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(15)

Published: Jan. 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.

Language: Английский

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Cobalt‐Catalyzed Enantioselective C−H Carbonylation towards Chiral Isoindolinones

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(10)

Published: Jan. 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.

Language: Английский

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Enantioselective Nickel-Electrocatalyzed Reductive Propargylic Carboxylation with CO₂

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(21), P. 14864 - 14874

Published: May 16, 2024

The exploitation of carbon dioxide (CO2) as a sustainable, plentiful, and harmless C1 source for the catalytic synthesis enantioenriched carboxylic acids has long been acknowledged pivotal task in synthetic chemistry. Herein, we present current-driven nickel-catalyzed reductive carboxylation reaction with CO2 fixation, facilitating formation C(sp3)–C(sp2) bonds by circumventing handling moisture-sensitive organometallic reagents. This electroreductive protocol serves practical platform, paving way propargylic (up to 98% enantiomeric excess) from racemic carbonates CO2. efficacy this transformation is exemplified its successful utilization asymmetric total (S)-arundic acid, (R)-PIA, (S)-chizhine D, (S)-cochlearin G, (S,S)-alexidine, thereby underscoring potential electrosynthesis achieve complex molecular architectures sustainably.

Language: Английский

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Second Generation Catalytic Enantioselective Nucleophilic Desymmetrization at Phosphorus (V): Improved Generality, Efficiency and Modularity

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(18)

Published: Feb. 21, 2024

A broadly improved second generation catalytic two-phase strategy for the enantioselective synthesis of stereogenic at phosphorus (V) compounds is described. This protocol, consisting a bifunctional iminophosphorane (BIMP) catalyzed nucleophilic desymmetrization prochiral, bench stable P(V) precursors and subsequent enantiospecific substitution allows divergent access to wide range C-, N-, O- S- substituted containing from handful enantioenriched intermediates. new ureidopeptide BIMP catalyst/thiaziolidinone leaving group combination allowed far wider substrate scope increased reaction efficiency practicality over previously established protocols. The resulting intermediates could then be transformed into an even greater distinct classes by displacement remaining as well allowing further diversification downstream. Density functional theory (DFT) calculations were performed pinpoint origin enantioselectivity BIMP-catalyzed desymmetrization, rationalize how superior catalyst/leaving leads generality in our second-generation system, shed light onto observed stereochemical retention inversion pathways when performing late-stage S

Language: Английский

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

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 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.

Language: Английский

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Cobaltaelectro-Catalyzed C–H Annulation with Allenes for Atropochiral and P-Stereogenic Compounds: Late-Stage Diversification and Continuous Flow Scale-Up

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(14), P. 9713 - 9723

Published: July 11, 2023

The 3d metallaelectro-catalyzed C-H activation has been identified as an increasingly viable strategy to access valuable organic molecules in a resource-economic fashion under exceedingly mild reaction conditions. However, the development of enantioselective is very challenging and its infancy. Here, we disclose merger cobaltaelectro-catalyzed with asymmetric catalysis for highly annulation allenes. A broad range C-N axially chiral P-stereogenic compounds were thereby obtained good yields up 98% high enantioselectivities >99% ee. practicality this approach was demonstrated by diversification complex bioactive drug well decagram scale electrocatalysis continuous flow.

Language: 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, Journal Year: 2023, Volume and Issue: 14(26), P. 7291 - 7303

Published: Jan. 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.

Language: Английский

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

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(40)

Published: Aug. 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.

Language: Английский

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