Dynamic Kinetic Reductive Grignard-Type Addition for the Construction of Axial and Central Chirality

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 1147 - 1157

Published: Jan. 3, 2025

This study describes a photoredox/cobalt dual-catalyzed asymmetric Grignard-type addition reaction, enabling the synthesis of axially chiral hexatomic (six–six) N-heterobiaryls bearing extra secondary alcohol unit via an efficient dynamic kinetic transformation racemic N-heterobiaryl triflate substrates. The conversion facilitated both photoredox and classical reductive reaction conditions exhibits good functional group tolerance, broad substrate scope, satisfactory stereoselectivity. Furthermore, control experiments density theory calculations provide preliminary mechanistic insights.

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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Enantioselective Desymmetrization of Biaryls via Cooperative Photoredox/Brønsted Acid Catalysis and Its Application to the Total Synthesis of Ancistrobrevolines

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 5, 2025

Photoredox catalysis has emerged as a powerful tool for forming and breaking chemical bonds, further taking hold with its integration asymmetric catalysis. While the dual-catalytic approach led to successful examples of control stereogenic centers, axes remained underexplored. In this study, an acylimine intermediate was generated through photoredox catalysis, symmetric substrate, 2-arylresorcinol, desymmetrized aid chiral phosphoric acid Using approach, center axis were successfully controlled provide natural-product-driven compound. The origins enantioselectivity diastereoselectivity investigated density functional theory study four possible enantiodetermining transition states. Consequently, first total syntheses ring-contracted naphthylisoquinoline alkaloid ancistrobrevolines A B accomplished concisely. This provides not only novel methodology strategy synthesize alkaloids but also direction advance catalytic research synthesis studies.

Language: Английский

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Multiple Atropo Selectivity by κ²‐N,O‐Oxazoline Urea Ligands in Cobaltaelectro‐Catalyzed C─H Activations: Decoding Selectivity with Data Science Integration

ChemistryEurope, Journal Year: 2025, Volume and Issue: unknown

Published: April 8, 2025

Enantioselective catalysis is one of the most prominent strategies in organic synthesis to access chiral bioactive compounds and advanced materials. Particularly, development ligands has significantly efficiency selectivity transition metal‐catalyzed enantioselective transformations. Over recent decades, numerous ligand classes with distinct geometrical electronic properties have been established. Despite these advances, demand for novel, tunable, highly effective persists, driven by need structurally diverse molecules pursuit greener, more sustainable catalytic processes. Herein, a novel class oxazoline ureas introduced their potential as κ 2 ‐ N , O ‐preligands metal demonstrated. The urea are featurized compared amide enol derivatives using physical descriptors. A multivariate linear regression model constructed quantitatively describe effect quinoline fragment from substrate on enantioselectivity. Moreover, effectively applied atropo‐enantioselective cobaltaelectro‐catalyzed C─H annulations 1‐alkynyl indoles.

Language: Английский

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Photochemical upcycling of polymers via visible light-driven C−H bond activation

Chemical Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

This mini-review highlights the scientific breakthroughs in photochemical upcycling polymers through oxidative degradation and post-polymerization modification via visible light-driven C–H bond activation.

Language: Английский

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Cascade [3 + 2]/[4 + 2] Cycloaddition of Enaminones with Vinylene Carbonate for the Synthesis of Functionalized Pyrrolo[2,1-a]isoquinoline Derivatives

Organic Letters, Journal Year: 2024, Volume and Issue: 26(45), P. 9752 - 9758

Published: Nov. 6, 2024

We developed a protocol for the synthesis of functionalized pyrrolo[2,1-a]isoquinoline derivatives (PIQDs) 3 from enaminones 1 using vinylene carbonate 2. This strategy involved [3 + 2] and [4 cycloadditions via heating mixture substrates with 2 DCE at 60 °C, catalyzed by [Cp*RhCl2]2 oxidized Cu(OAc)2 AgSbF6 promoted NaOAc. As we increased reaction temperature to 110 °C under same conditions, synthesized PIQDs 4 through sequential C–H activation, alkene insertion, migratory C–N reductive elimination, β-O finally dehydration. result, series 3–4 were generated forming four bonds (2 C–C bonds) in single step. realizes linear molecules potential biological activity, specifically natural-like heterocycles (3–4). It expands application as C2 synthon construction pyrrole isoquinoline skeletons combinatorial parallel syntheses one-pot reactions.

Language: Английский

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Substrate NOBINAc ligand affinity for Pd^II-catalyzed enantioselective C–H activation over reactive β-C–H bonds in ferrocenyl amines

Chemical Science, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 13, 2024

Ferrocenyl amines as directing groups for C–H activation have limitations they are prone to undergo oxidation, allylic deamination, and β-hydride elimination.

Language: Английский

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Photoinduced Vitamin-B₁₂-Catalyzed meta-C–H Bromination/Chlorination of Phenol Derivatives Assisted by a U-Shaped Nitrile Template

Organic Letters, Journal Year: 2024, Volume and Issue: 26(42), P. 9073 - 9078

Published: Oct. 15, 2024

A photoinduced vitamin-B

Language: Английский

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