Controlling Reactivity and Selectivity in the Nondirected C–H Activation of Arenes with Palladium

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(18), P. 2459 - 2472

Published: Aug. 24, 2023

ConspectusAromatic structures are widespread motifs throughout organic chemistry, and C-H activation has been recognized as a major tool for enabling their sustainable efficient functionalization. Through activation, arenes can be modified without the need prefunctionalization, leading to inherent atom- step-economic advantages over traditional methods. However, development of synthetically useful methods, several hurdles have overcome. The strength bonds necessitates sufficiently reactive catalysts, while presence multiple within substrate poses challenges in terms site-selectivity. Traditionally these addressed by control. By attaching different directing groups (DGs), reactivity respective arene was significantly enhanced DG guided metal close proximity specific bonds, resulting high introduction removal add additional steps synthetic sequence, scope reaction is limited class. complementary nondirected methods that applied broad range necessity carry functional group coordinates Pd (referred simple arenes) therefore highly desirable. intrinsically lower such substrates absence selectivity-determining pose significant solved only catalysts. Consequently, field especially with respect Pd-catalyzed remained comparatively underdeveloped when we initiated our research program 2017. At time, state-of-the-art required used large excess, precluding its use late-stage Since organopalladium species among most versatile intermediates, realized developing system, which effectively selectively activate limiting reagent, would powerful chemistry. This account summarizes groups' toward application catalytic systems offering this desired focuses explicitly on functionalization reactions arenes, where employed reagent. After an state before 2017 associated challenges, experimental mechanistic details about first arene-limited, palladium will discussed. enabled identification combination two ligands, N-heterocycle amino acid-derived ligand. Afterward discuss expansion dual-ligand approach further arene-limited transformations. Finally, describe methodologies originated from observations made during studies, namely, deuteration selective olefination method uses noncovalent interactions induce meta selectivity.

Language: Английский

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Advancing Heterogeneous Organic Synthesis With Coordination Chemistry‐Empowered Single‐Atom Catalysts

Advanced Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 18, 2024

Abstract For traditional metal complexes, intricate chemistry is required to acquire appropriate ligands for controlling the electron and steric hindrance of active centers. Comparatively, preparation single‐atom catalysts much easier with more straightforward effective accesses arrangement control The presence coordination atoms or neighboring functional on supports' surface ensures stability single‐atoms their interactions individual substantially regulate performance Therefore, collaborative interaction between surrounding environment enhances initiation reaction substrates formation transformation crucial intermediate compounds, which imparts significant catalytic efficacy, rendering them a valuable framework investigating correlation structure activity, as well mechanism in organic reactions. Herein, comprehensive overviews both homogeneous complexes reactions are provided. Additionally, reflective conjectures about advancement synthesis also proposed present reference later development.

Language: Английский

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Mn(I)-Catalyzed Preferential Electrophilic C3-Maleimidation in Quinoxaline Leading to Spirocyclization and Dehydrogenation of Succinimides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(20), P. 3806 - 3811

Published: May 17, 2023

A Mn(I)-catalyzed site-selective nondirected C3-maleimidation of quinoxaline is established. Herein, the electrophilic C3-metalation precedes over o-directed strategy to access diversely substituted quinoxaline-appended succinimides. The products undergo PIFA-promoted C(sp2)-C(sp3) spirocyclization via π-electrons drifting from aryls and Selectfluor-mediated dehydrogenation succinimide at room temperature.

Language: Английский

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Palladium(II)‐Catalyzed Nondirected Late‐Stage C(sp²)−H Deuteration of Heteroarenes Enabled Through a Multi‐Substrate Screening Approach

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(27)

Published: March 21, 2024

The importance of deuterium labelling in a variety applications, ranging from mechanistic studies to drug-discovery, has spurred immense interest the development new methods for its efficient incorporation organic, and especially bioactive molecules. five-membered heteroarenes at center this work are ubiquitous motifs molecules these compounds therefore highly desirable. However, profound differences chemical properties encountered between different hamper single set broadly applicable reaction conditions, often necessitating separate optimization campaign given type heteroarene. In study we describe use multi-substrate screening approach identify optimal conditions classes minimal number reactions. Using approach, four sets complementary derived our dual ligand-based palladium catalysts nondirected C(sp

Language: Английский

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Palladium(II) NCS‐Pincer Complexes Mediated Regioselective Cross Dehydrogenative Alkenation of 2‐Arylthiophenes

ChemCatChem, Journal Year: 2024, Volume and Issue: 16(15)

Published: March 18, 2024

Abstract In this report, we have synthesized two new NCS pincer ligands by the Schiff base reaction of 3‐((phenylthio)methoxy)benzaldehyde ( P ) with alkyl amines t butylamine L1 and 1‐adamantylamine L2 )). The palladium complexes butylamine= C1 1‐adamantylamine= C2 these were their PdCl 2 (CH 3 CN) precursor. newly characterized using various analytical spectroscopic techniques such as 1 H, 13 C{ H} Nuclear Magnetic Resonance (NMR), Ultraviolet–visible (UV‐Visible), Fourier Transform Infrared (FTIR) Spectroscopy, High‐Resolution Mass Spectrometry (HRMS). structure ligand its coordination mode precursor studied help single‐crystal X‐ray diffraction. showed distorted square planar geometry around center. used catalysts for regioselective cross‐dehydrogenative alkenation 2‐arylthiophene derivatives. complex , where sterically bulky adamantyl is part side arm a higher yield reaction. Only 2.5 mol% catalyst loading was sufficient to achieve 74–95 % yields desired products excellent functional group tolerance under mild conditions. poisoning experiments (PPh Hg) homogeneous nature catalytic process. plausible mechanism proposed based on control time‐dependent HRMS studies.

Language: Английский

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Extended π-conjugated systems by external ligand-assisted C−H olefination of heterocycles: Facile access to single-molecular white-light-emitting and NIR fluorescence materials

Chinese Chemical Letters, Journal Year: 2024, Volume and Issue: unknown, P. 110113 - 110113

Published: June 1, 2024

Language: Английский

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Orthogonal Olefination with Organogermanes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(43)

Published: Sept. 12, 2023

Reported herein is a fully orthogonal olefination, which involves the site- and E-selective coupling of aryl germanes with alkenes, tolerating otherwise widely employed handles such as aromatic (pseudo)halogens (C-I, C-Br, C-Cl, C-F, C-OTf, C-OSO2 F), silanes boronic acid derivatives well alternative functionalities. This unprecedented [Ge]-based oxidative Heck proceeds at room temperature high speed (10 min to 2 hours) operational simplicity owing its base-free air-tolerant features.

Language: Английский

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BINAP‐Accelerated Photoinduced Trifluoromethylation of (Hetero)Aryl Iodides

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

Published: March 6, 2025

Abstract Trifluoromethyl groups hold significance in the bioactivity and physical properties of organic molecules. Contemporary approaches to trifluoromethylated aromatics typically involve coupling CuCF 3 reagents with aryl halides, which is limited by difficulty oxidative addition copper organohalides. Herein, a photoinduced ligand‐catalyzed trifluoromethylation/pentafluoroethylation (hetero)aryl iodides presented. The conversion C─I bond into C─CF enabled photochemistry copper, produces radicals situ generated from Ruppert–Prakash reagent under visible light. This radical approach circumvents challenge catalytic amount rac ‐BINAP substantially accelerates whole process, allowing reaction complete within 1 h very mild conditions without using any additional photo‐redox catalysts. readily availability starting material, high efficiency, broad utility make this transformation attractive for practitioners synthetic medicinal chemistry.

Language: Английский

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Palladium-Catalyzed ortho C–H Allylation of Tertiary Anilines

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 26, 2025

Allyl groups could be transformed into various functional groups. A novel and highly regioselective approach for the Pd-catalyzed ortho C–H allylation of tertiary anilines has been developed. Various substitution were well-tolerated, allylated linezolid, ibuprofen, naproxen, ketoprofen, dehydroabietic acid derivatives easily prepared. Notably, this new method overcomes limitations classical amide-directing groups, as amide are well-tolerated in reaction. Preliminary mechanistic studies revealed that a dual-ligand effect may involved achieving excellent selectivity reaction facilitated by N-Bz-Gly Ag2CO3. Further indicate FeCl3 is necessary Lewis to activate allyl bromide.

Language: Английский

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Fujiwara-Moritani reaction: challenges and new opportunities

Tetrahedron Chem, Journal Year: 2025, Volume and Issue: unknown, P. 100130 - 100130

Published: April 1, 2025

Language: Английский

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