Transition metal-catalyzed site- and regio-divergent C–H bond functionalization

Chemical Society Reviews, Год журнала: 2017, Номер 46(14), С. 4299 - 4328

Опубликована: Янв. 1, 2017

The regioselectivity of C–H functionalization reactions can be redirected to obtain regioisomeric products form the same starting materials.

Язык: Английский

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Toolbox for Distal C–H Bond Functionalizations in Organic Molecules

Chemical Reviews, Год журнала: 2021, Номер 122(6), С. 5682 - 5841

Опубликована: Окт. 18, 2021

Transition-metal-catalyzed C–H activation has developed a contemporary approach to the omnipresent area of retrosynthetic disconnection. Scientific researchers have been tempted take help this methodology plan their synthetic discourses. This paradigm shift helped in development industrial units as well, making synthesis natural products and pharmaceutical drugs step-economical. In vast zone bond activation, functionalization proximal bonds gained utmost popularity. Unlike bonds, distal is more strenuous requires distinctly specialized techniques. review, we compiled various methods adopted functionalize mechanistic insights within each these procedures, scope methodology. With give complete overview expeditious progress made field organic chemistry while also highlighting its pitfalls, thus leaving open for further modifications.

Язык: Английский

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Recent advances in positional-selective alkenylations: removable guidance for twofold C–H activation

Organic Chemistry Frontiers, Год журнала: 2017, Номер 4(7), С. 1435 - 1467

Опубликована: Янв. 1, 2017

Recent advances in transition-metal catalyzed positional-selective alkenylations via twofold C–H activation directed by removable or traceless directing groups are reviewed.

Язык: Английский

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Remote para-C–H Functionalization of Arenes by a D-Shaped Biphenyl Template-Based Assembly

Journal of the American Chemical Society, Год журнала: 2015, Номер 137(37), С. 11888 - 11891

Опубликована: Сен. 11, 2015

Site-selective C–H functionalization has emerged as an efficient tool in simplifying the synthesis of complex molecules. Most often, directing group (DG)-assisted metallacycle formation serves strategy to ensure promising regioselectivity. A wide variety ortho- and meta-C–H functionalizations stand examples this regard. Yet despite significant progress, DG-assisted selective para-C–H arenes remained unexplored, mainly because it involves a geometrically constrained metallacyclic transition state. Here we report easily recyclable, novel Si-containing biphenyl-based template that directs distal p-C–H bond toluene by forming D-shaped assembly. This DG allows required flexibility support oversized pre-transition By overcoming electronic steric bias, para-olefination acetoxylation were successfully performed while undermining o- m-C–H activation. The applicability biphenyl template-based is demonstrated synthesizing various

Язык: Английский

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N-Acyl Amino Acid Ligands for Ruthenium(II)-Catalyzed meta-C–H tert-Alkylation with Removable Auxiliaries

Journal of the American Chemical Society, Год журнала: 2015, Номер 137(43), С. 13894 - 13901

Опубликована: Сен. 29, 2015

Acylated amino acid ligands enabled ruthenium(II)-catalyzed C-H functionalizations with excellent levels of meta-selectivity. The outstanding catalytic activity the ruthenium(II) complexes derived from monoprotected acids (MPAA) set stage for first ruthenium-catalyzed meta-functionalizations removable directing groups. Thereby, meta-alkylated anilines could be accessed, which are difficult to prepare by other means direct aniline functionalizations. robust nature versatile ruthenium(II)-MPAA was reflected challenging remote transformations tertiary alkyl halides on derivatives as well pyridyl-, pyrimidyl-, and pyrazolyl-substituted arenes. Detailed mechanistic studies provided strong support an initial reversible ruthenation, followed a SET-type C-Hal activation through homolytic bond cleavage. Kinetic analyses confirmed this hypothesis unusual second-order dependence reaction rate ruthenium catalyst concentration. Overall, report highlights exceptional acylated acids, should prove instrumental chemistry beyond functionalization.

Язык: Английский

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Achieving Site-Selectivity for C–H Activation Processes Based on Distance and Geometry: A Carpenter’s Approach

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(24), С. 10571 - 10591

Опубликована: Май 21, 2020

The ability to differentiate between highly similar C–H bonds in a given molecule remains fundamental challenge organic chemistry. In particular, the lack of sufficient steric and electronic differences located distal functional groups has prevented development site-selective catalysts with broad scope. An emerging approach circumvent this obstacle is utilize distance target bond coordinating group, along geometry cyclic transition state directed activation, as core molecular recognition parameters multiple bonds. Perspective, we discuss advent recent advances concept. We cover wide range transition-metal-catalyzed, template-directed remote activation reactions alcohols, carboxylic acids, sulfonates, phosphonates, amines. Additionally, review eminent examples which take advantage non-covalent interactions achieve regiocontrol. Continued advancement distance- geometry-based differentiation for regioselective functionalization may lead ultimate realization editing: freedom modify molecules at any site, order.

Язык: Английский

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HFIP in Organic Synthesis

Chemical Reviews, Год журнала: 2022, Номер 122(15), С. 12544 - 12747

Опубликована: Июль 17, 2022

1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) is a polar, strongly hydrogen bond-donating solvent that has found numerous uses in organic synthesis due to its ability stabilize ionic species, transfer protons, and engage range of other intermolecular interactions. The use this exponentially increased the past decade become choice some areas, such as C–H functionalization chemistry. In review, following brief history HFIP an overview physical properties, literature examples reactions using or additive are presented, emphasizing effect each reaction.

Язык: Английский

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Arene diversification through distal C(sp ² )−H functionalization

Science, Год журнала: 2021, Номер 372(6543)

Опубликована: Май 13, 2021

Transition metal-catalyzed aryl C-H activation is a powerful synthetic tool as it offers step and atom-economical routes to site-selective functionalization. Compared with proximal ortho-C-H activation, distal (meta- and/or para-) remains more challenging due the inaccessibility of these sites in formation energetically favorable organometallic pretransition states. Directing catalyst toward bonds requires judicious template engineering design, well prudent choice ligands. This review aims summarize recent elegant discoveries exploiting directing group assistance, transient mediators or traceless directors, noncovalent interactions, ligand selection control activation.

Язык: Английский

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Accessing Remote meta‐ and para‐C(sp²)−H Bonds with Covalently Attached Directing Groups

Angewandte Chemie International Edition, Год журнала: 2018, Номер 58(32), С. 10820 - 10843

Опубликована: Ноя. 29, 2018

Directing group assisted ortho-C-H activation has been known for the last few decades. In contrast, extending same approach to achieve of distal meta- and para-C-H bonds in aromatic molecules remained elusive a long time. The main challenge is conception macrocyclic transition state, which needed anchor metal catalyst close target bond. Judicious modification chain length, tether linkage, nature catalyst-coordinating donor atom led number successful studies years. This Review compiles significant achievements made this field both para-selectivity using covalently attached directing groups, are systematically classified on basis their mode covalent attachment substrate as well chemical nature. aims create more heuristic recognizing suitability groups use future organic transformations.

Язык: Английский

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Metal-catalyzed C H activation/functionalization: The fundamentals

Journal of Molecular Catalysis A Chemical, Год журнала: 2016, Номер 426, С. 275 - 296

Опубликована: Сен. 9, 2016

Язык: Английский

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