Diboron(4)‐Catalyzed Remote [3+2] Cycloaddition of Cyclopropanes via Dearomative/Rearomative Radical Transmission through Pyridine

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(52)

Опубликована: Ноя. 8, 2022

Abstract Ring structures such as pyridine, cyclopentane or their combinations are important motifs in bioactive molecules. In contrast to previous cycloaddition reactions that necessitated a directly bonded initiating functional group, this work demonstrated novel through‐(hetero)arene radical transmission concept for selective activation of remote bond. An efficient, metal‐free and atom‐economical [3+2] between 4‐pyridinyl cyclopropanes alkenes alkynes has been developed modular synthesis pyridine‐substituted cyclopentanes, cyclopentenes bicyclo[2.1.1]hexanes difficult access using known methods. This complexity‐building reaction was catalyzed by very simple inexpensive diboron(4) compound took place via dearomative/rearomative processes. The substrate scope broad more than 100 new compounds were prepared generally high yields. Mechanistic experiments density function theory (DFT) investigation supported relay catalytic cycle involving alkylidene dihydropyridine intermediates boronyl transfer.

Язык: Английский

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Remote steric control for undirected meta -selective C–H activation of arenes

Science, Год журнала: 2022, Номер 375(6581), С. 658 - 663

Опубликована: Фев. 10, 2022

Regioselective functionalization of arenes remains a challenging problem in organic synthesis. Steric interactions are often used to block sites adjacent given substituent, but they do not distinguish the remaining remote sites. We report strategy based on steric control, whereby roof-like ligand protects distant para site addition ortho sites, and thereby enables selective activation meta carbon-hydrogen (C–H) bonds absence or substituents. demonstrate this concept for iridium-catalyzed -selective borylation various monosubstituted arenes, including complex drug molecules. This has potential expand toolbox C–H bond previously nondifferentiable reaction

Язык: Английский

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Traditional and sustainable approaches for the construction of C–C bonds by harnessing C–H arylation

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Фев. 28, 2022

Abstract Biaryl scaffolds are found in natural products and drug molecules exhibit a wide range of biological activities. In past decade, the transition metal-catalyzed C–H arylation reaction came out as an effective tool for construction biaryl motifs. However, traditional reactions have limitations like harsh conditions, narrow substrate scope, use additives etc. therefore encouraged synthetic chemists to look alternate greener approaches. This review aims draw general overview on bond formation C–C bonds with aid different methodologies, majorly highlighting sustainable

Язык: Английский

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Transition metal–catalyzed remote C─H borylation: An emerging synthetic tool

Science Advances, Год журнала: 2023, Номер 9(16)

Опубликована: Апрель 21, 2023

Transition metal–catalyzed C─H bond activation and borylation is a powerful synthetic method that offers versatile transformation from organoboron compounds to virtually all other functional groups. Compared the ortho-borylation, remote remains more challenging owing inaccessibility of these bonds. Enforcing metal catalyst toward bonds needs well-judged design through proper ligand development. This review article aims summarize recent discoveries for by employment new catalyst/ligand with help steric ligand, noncovalent interactions. It has been found now takes part in total synthesis natural products shorter route. Whereas, Ir-catalyzed predominant, cobalt also started affect this field sustainable cost-effective

Язык: Английский

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Transition-metal catalyzed C–H activation as a means of synthesizing complex natural products

Chemical Society Reviews, Год журнала: 2023, Номер 52(21), С. 7461 - 7503

Опубликована: Янв. 1, 2023

Over the past few decades, advent of C–H activation has led to a rethink among chemists about synthetic strategies employed for multi-step transformations.

Язык: Английский

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Enroute sustainability: metal free C–H bond functionalisation

Chemical Society Reviews, Год журнала: 2023, Номер 52(7), С. 2391 - 2479

Опубликована: Янв. 1, 2023

The metal-free C–H functionalisation is providing environmentally benign, cost-effective, sustainable catalytic systems. Comprehensive developments of various reactions are the focal point this review.

Язык: Английский

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Discovery of Organic Optoelectronic Materials Powered by Oxidative Ar–H/Ar–H Coupling

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(2), С. 1224 - 1243

Опубликована: Янв. 4, 2024

Efficient and streamlined synthetic methods that facilitate the rapid build-up of structurally diverse π-conjugated systems are paramount importance in quest for organic optoelectronic materials. Among these methods, transition-metal-catalyzed oxidative Ar–H/Ar–H coupling reactions between two (hetero)arenes have emerged as a concise effective approach generating wide array bi(hetero)aryl fused heteroaryl structures. This innovative bypasses challenges associated with substrate pre-activation processes, thereby allowing creation frameworks were previously beyond reach using conventional Ar–X/Ar–M reactions. These inherent advantages ushered new design patterns molecules deviate from traditional methods. ground-breaking enables transcendence limitations repetitive material structures, ultimately leading to discovery novel high-performance In this Perspective, we provide an overview recent advances development materials through utilization We introduce several notable strategies domain, covering both directed non-directed strategies, dual chelation-assisted strategy ortho-C–H arylation/cyclization strategy. Additionally, shed light on role advancement Finally, discuss current existing protocols offer insights into future prospects field.

Язык: Английский

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Remote site-selective arene C–H functionalization enabled by N-heterocyclic carbene organocatalysis

Nature Catalysis, Год журнала: 2024, Номер 7(8), С. 900 - 911

Опубликована: Июль 11, 2024

Язык: Английский

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Emergence of Pyrimidine-Based meta-Directing Group: Journey from Weak to Strong Coordination in Diversifying meta-C–H Functionalization

Accounts of Chemical Research, Год журнала: 2022, Номер 55(3), С. 354 - 372

Опубликована: Янв. 12, 2022

C-H activation has emerged as a powerful transformative synthetic tool to construct complex molecular frameworks, which are ubiquitous in natural products, medicines, dyes, polymers, and many more. However, reactivity selectivity, arising from the inertness of bonds their overabundance organic molecules, two major fundamental challenges developing various carbon-carbon (C-C) carbon-heteroatom (C-X) bond formation reactions via technique. Functional groups with coordinating capacity transition metal catalysts, profoundly known directing (DGs), have shown great promise exerting selective activation, often called site-selective or regioselective transformation target molecule. Advent group (DG)-assisted strategies not only resolved selectivity issues but also offers unique solution rapid synthesis molecules convenient predictable manner. Our laboratory, this regard, is fascinated by prospect DG-assisted distal functionalization arenes, remotely located existing group. Notably, opposition proximal ortho-C-H proceeded an energetically favorable five- seven-membered metallacycle, remained formidable challenge it required large macrocyclic metallacycle. Therefore, designing suitable template that would maintain distance geometric relationship between appended auxiliary order ensure prolific delivery catalyst closest proximity targeted was key success. In Yu devised elegant "U-shaped" for first time execute meta-C-H recruiting cyano-based initial effort diversify scope using led us realize "cyano-based DGs" intrinsically limited weak ability, competitive binding mode (end-on vs side-on), incompatibility acidic basic reaction conditions. search robust auxiliary, we were intrigued possibility strongly ability pyrimidine quinoline-based DGs.In Account, describe our journey weakly DG pyrimidine-based achieve diverse electronically sterically unbiased arenes. While some functionalizations achieved finding conditions, others mechanistic understanding. development realm constrained short linkers, attached arene interest through 2-4 atoms. later studies, demonstrated can be attained even though 10-atoms away arene. More importantly, transient successfully utilized deliver olefination arenes situ imine formation, provided step-economic route activation.We hope Account will stimulate further design provide guiding platform future functionalization.

Язык: Английский

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Dual Ligand Enabled Nondirected C–H Chalcogenation of Arenes and Heteroarenes

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(27), С. 12032 - 12042

Опубликована: Июнь 27, 2022

Chalcogenide motifs are present as principal moieties in a vast array of natural products and complex molecules. Till date, the construction these chalcogen has been restricted to either use directing groups or employment large excess electronically activated arenes, typically employed cosolvent. Despite being highly effective, methods have their own limitations step economy deployment an amount arenes. Herein, we report evolution catalytic system employing arene-limited, nondirected thioarylation arenes heteroarenes using complimentary dual-ligand approach. The reaction is controlled by combination steric electronic factors, utilization suitable ligand enables generation on spectrum that generated classical methods. ligands remains imperative protocol with theoretical calculations pointing towards monoprotected amino acid crucial concerted metalation deprotonation (CMD) mechanism characteristic [5,6]-palladacyclic transition state, while pyridine moiety assists active catalyst species formation product release. Combined experimental computational mechanistic investigations point toward C–H activation both regio- rate-determining. Interestingly, oxidative addition diphenyl disulfide substrate found be unlikely, alternative transmetalation-like involving Pd–Ag heterometallic proposed operative.

Язык: Английский

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