Kinetic and thermodynamic control of C(sp ² )–H activation enables site-selective borylation

Science, Год журнала: 2023, Номер 382(6675), С. 1165 - 1170

Опубликована: Дек. 7, 2023

Catalysts that distinguish between electronically distinct carbon-hydrogen (C–H) bonds without relying on steric effects or directing groups are challenging to design. In this work, cobalt precatalysts supported by N -alkyl-imidazole–substituted pyridine dicarbene (ACNC) pincer ligands described enable undirected, remote borylation of fluoroaromatics and expansion scope include electron-rich arenes, pyridines, tri- difluoromethoxylated thereby addressing one the major limitations first-row transition metal C–H functionalization catalysts. Mechanistic studies established a kinetic preference for bond activation at meta -position despite cobalt-aryl complexes resulting from ortho being thermodynamically preferred. Switchable site selectivity in as function boron reagent was preliminarily demonstrated using single precatalyst.

Язык: Английский

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Noncovalent interaction with a spirobipyridine ligand enables efficient iridium-catalyzed C–H activation

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Апрель 17, 2024

Abstract Exploitation of noncovalent interactions for recognition an organic substrate has received much attention the design metal catalysts in synthesis. The CH–π interaction is especially interest molecular because both C–H bonds and π electrons are fundamental properties molecules. However, their weak nature, these have been less utilized control reactions. We show here that can be used to kinetically accelerate catalytic activation arenes by directly recognizing π-electrons arene substrates with a spirobipyridine ligand. Computation ligand kinetic isotope effect study provide evidence between backbone substrate. rational exploitation will open new avenues catalysis.

Язык: Английский

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C–H borylation: a tool for molecular diversification

Organic Chemistry Frontiers, Год журнала: 2023, Номер 11(3), С. 929 - 953

Опубликована: Дек. 19, 2023

Iridium-catalyzed C–H activation and borylation has become as a powerful synthetic tool in the past few decades because of widespread applicability versatility organoboron compounds.

Язык: Английский

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Air‐Stable Bis‐Cyclometallated Iridium Catalysts for Ortho‐Directed C(sp²)−H Borylation

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(10), С. 2292 - 2304

Опубликована: Март 21, 2024

Abstract We report a class of isolable bis‐cyclometallated iridium precatalysts (ImIr) and their use in regioselective ortho −C−H borylation aromatic, heteroaromatic, acrylic, aliphatic systems. The catalysts consist two imine ligands an acetate coordinated to (III) center. character ImIr warrants its compatibility with high‐throughput experimentation, prerequisite for applications late‐stage functionalization (LSF) complex substrates. Initial mechanistic studies point towards inner‐sphere mechanism involving species shedding light on the general understanding ‐selective C−H borylations.

Язык: Английский

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Trialkoxysilane-Induced Iridium-Catalyzed para-Selective C–H Bond Borylation of Arenes

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Апрель 2, 2024

Abstract An ideal approach for the construction of aryl boron compounds is to selectively replace a C–H bond in arenes with C–B bond, and controlling regioselectivity one most challenging aspects these transformations. Herein, we report an iridium-catalyzed trialkoxysilane protecting group-assisted regioselective borylation arenes, including derivatives benzaldehydes, acetophenones, benzoic acids, benzyl alcohols, phenols, silanes, multi-functionalized aromatic rings are all well tolerated gave para - selective products short time without requirement inert gases atmosphere. The site-selective can be adjustable by installing developed group on different functional groups ring. Importantly, preparation process trialkoxychlorosilane efficient scalable. Mechanistic computational studies reveal that steric hindrance plays key role dictating -selectivity.

Язык: Английский

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Nucleophilic Substitution at Unactivated Arene C–H: Copper-Catalyzed anti-Selective Silylative Cyclization of Substituted Benzylacetylenes

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Фев. 13, 2025

A new mode of carbon-carbon bond formation via electrophilic activation a C-H has been developed in the context copper-catalyzed anti-selective silylative cyclization benzylacetylenes with silylboronates for synthesis 2-silyl-1H-indenes. The reaction proceeds high regioselectivity various substituted benzylacetylenes, and resulting products could be further functionalized. arene that undergoes acts as an electrophile release hydride under redox neutral conditions, mechanism was probed by deuterium-labeling experiments density functional theory calculations.

Язык: Английский

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Ir-Catalyzed, Nitrogen-Directed C(sp³)–H and C(sp²)–H Borylation with a Spiro-Fluorene-Indenoindenyl Ligand

ACS Catalysis, Год журнала: 2025, Номер unknown, С. 4061 - 4068

Опубликована: Фев. 21, 2025

Язык: Английский

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Copper-Catalyzed C–B(sp³) Bond Formation through the Intermediacy of Cu–B(sp³) Complex

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Апрель 15, 2025

The vast majority of transition metal (TM) catalyzed borylative transformations rely on TM-B(sp2) complexes. Contrastingly, the chemistry TM-B(sp3) species and their potential in catalytic borylation remain surprisingly underdeveloped, due probably to lack suitable boron(sp3) reagents. Herein, we employ our recently developed sp2-sp3 diboron reagent successfully enable a copper-catalyzed hydroboration allenes for C-B(sp3) bond formation. A comprehensive mechanistic study, including isolation structural characterization Cu-B(sp3) complex, substantiates presence intermediate cycle.

Язык: Английский

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Site‐Selective Ortho/Ipso C−H Difunctionalizations of Arenes using Thianthrene as a Leaving Group

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(30)

Опубликована: Май 7, 2024

Abstract Site‐selective ortho/ipso C−H difunctionalizations of aromatic compounds were designed to afford polyfunctionalized arenes including challenging 1,2,3,4‐tetrasubstituted ones (62 examples, up 97 % yields). To ensure the excellent regioselectivity process while keeping high efficiency, an original strategy based on a “C−H thianthenation/Catellani‐type reaction” sequence was developed starting from simple arenes. Non‐prefunctionalized first regioselectively converted into corresponding thianthrenium salts. Then, palladium‐catalyzed, norbornene (NBE)‐mediated allowed synthesis ipso ‐olefinated/ ortho ‐alkylated using thianthrene as leaving group (revisited Catellani reaction). Pleasingly, commercially available (NBE) and unique catalytic system, synthetic challenges known for reaction with aryl iodides smoothly successfully tackled “thianthrenium” approach. The protocol robust (gram‐scale reaction) widely applied two‐fold functionalization various bio‐active compounds. Moreover, panel olefins alkyl halides coupling partners suitable. further incorporation other groups at (CN/alkyl/H, aryl) (alkyl, aryl, amine, thiol) positions, showcasing generality process.

Язык: Английский

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Palladium‐Catalyzed Remote C–H Functionalization: Non‐Covalent Interactions and Reversibly Bound Templates

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(44)

Опубликована: Июль 27, 2024

Abstract Pd‐catalysis has stood as a pivotal force in synthetic transformations for decades, maintaining its status paramount tool the realm of C−H bond activation. While functionalization at proximal positions become commonplace, achieving selective and sustainable access to distal continues captivate scientific endeavors. Recently, noteworthy trend emerged, focusing on utilization non‐covalent interactions address challenges associated with remote functionalization. The integration these into palladium catalysis stands justified response demands positions. This review delves latest advancements trends surrounding incorporation within field catalysis. Furthermore, it is emphasize that multifunctional templates, particularly those harnessing hydrogen bonding, present an elegant sophisticated approach activate bonds highly directed fashion. These templates showcase versatility demonstrate potential applications across diverse contexts area

Язык: Английский

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