3d Transition Metals for C–H Activation

Chemical Reviews, Год журнала: 2018, Номер 119(4), С. 2192 - 2452

Опубликована: Ноя. 27, 2018

C–H activation has surfaced as an increasingly powerful tool for molecular sciences, with notable applications to material crop protection, drug discovery, and pharmaceutical industries, among others. Despite major advances, the vast majority of these functionalizations required precious 4d or 5d transition metal catalysts. Given cost-effective sustainable nature earth-abundant first row metals, development less toxic, inexpensive 3d catalysts gained considerable recent momentum a significantly more environmentally-benign economically-attractive alternative. Herein, we provide comprehensive overview on until summer 2018.

Язык: Английский

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Late‐Stage Peptide Diversification by Position‐Selective C−H Activation

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(45), С. 14700 - 14717

Опубликована: Июль 3, 2018

The late-stage modification of structurally complex peptides bears great potential for drug discovery, crop protection, and the pharmaceutical industry, among others. Whereas traditional approaches largely rely on prefunctionalizations, C-H activation catalysis has in recent years emerged as an increasingly powerful tool post-translational peptide modifications a step-economic manner. Herein, we summarize progress organometallic until June 2018, including position- chemoselective palladium-, ruthenium-, manganese-catalyzed processes.

Язык: Английский

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From C4 to C7: Innovative Strategies for Site-Selective Functionalization of Indole C–H Bonds

Accounts of Chemical Research, Год журнала: 2021, Номер 54(7), С. 1723 - 1736

Опубликована: Март 12, 2021

The widespread presence of hydrocarbons makes C-H functionalization an attractive alternative to traditional cross-coupling methods. As indole is important heteroarene in a plethora natural products and pharmaceuticals, moieties has emerged as one the most topics this field. Due multiple bonds indoles, site selectivity long-standing challenge. Much effort been devoted indoles at C3 or C2 position, while accessing benzene core (from C4 C7) considerably more challenging.This Account summarizes our recent efforts toward site-selective based on innovative strategies. A common method solve issue involves development directing groups (DGs). Our early studies establish that installation N-P(O)tBu2 group N position can produce C7 C6 arylation using palladium copper catalysts, respectively. developed system also be extended direct C5 positions by installing pivaloyl position. Further investigation bearing N-PtBu2 shows diverse reactivity for functionalizations including arylation, olefination, acylation, alkylation, silylation, carbonylation with different coupling partners. Compared P(V) DG, P(III) easily attached substrates detached from products. However, these reactions rely mostly precious metal catalysts ligands; requirement significant limitation, particularly large-scale syntheses necessity removal toxic trace metals pharmaceutical We have uncovered general strategy chelation-assisted aromatic borylation just simple BBr3 under mild conditions, which N1 selectively deliver boron species unfavorable allow subsequent without any metal. This transition-metal-free synthesize hydroxylated boron-mediated directed hydroxylation reaction conditions broad functional compatibility.In Account, we describe contributions topic since 2015. These provide efficient methods divergent synthesis valuable substituted insights into exploration new strategies directives other heteroarenes.

Язык: Английский

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Cobalt-Catalyzed Enantioselective C–H Arylation of Indoles

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(2), С. 798 - 806

Опубликована: Янв. 10, 2022

Atropoisomeric (hetero)biaryls are scaffolds with increasing importance in the pharmaceutical and agrochemical industries. Although it is most obvious disconnection to construct such compounds, direct enantioselective C–H arylation through concomitant induction of chiral information remains extremely challenging uncommon. Herein, unprecedented earth-abundant 3d-metal-catalyzed atroposelective reported, furnishing rare atropoisomeric C2-arylated indoles. Kinetic studies DFT computation revealed an uncommon mechanism for this asymmetric transformation, oxidative addition being rate- enantio-determining step. Excellent stereoselectivities were reached (up 96% ee), while using unusual N-heterocyclic carbene ligand bearing essential remote substituent. Attractive dispersion interactions along positive C–H---π exerted by identified as key factors guarantee excellent enantioselection.

Язык: Английский

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Catalytic Au(i)/Au(iii) arylation with the hemilabile MeDalphos ligand: unusual selectivity for electron-rich iodoarenes and efficient application to indoles

Chemical Science, Год журнала: 2019, Номер 10(30), С. 7183 - 7192

Опубликована: Янв. 1, 2019

The ability of the hemilabile (P,N) MeDalphos ligand to trigger oxidative addition iodoarenes gold has been thoroughly studied. Competition experiments and Hammett correlations substantiate a clear preference for electron-enriched substrates both in stoichiometric reactions catalytic C-C cross-coupling with 1,3,5-trimethoxybenzene. This feature markedly contrasts higher reactivity electron-deprived typically encountered palladium. Based on DFT calculations detailed analysis key transition states (using NBO, CDA ETS-NOCV methods particular), different behavior two metals is proposed result from inverse electron flow between substrate metal. Indeed, iodobenzene associated charge transfer metal at state gold, but opposite electrophilicity center favors electron-rich while important back-donation palladium electron-poor substrates. Facile combined propensity gold(iii) complexes readily react (hetero)arenes prompted us apply (MeDalphos)AuCl complex arylation indoles, challenging very transformation. proved be efficient, general robust. It displays complete regioselectivity C3 arylation, it tolerates variety functional groups iodoarene indole partners (NO2, CO2Me, Br, OTf, Bpin, OMe…) proceeds under mild conditions (75 °C, 2 h).

Язык: Английский

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Transition-metal-catalyzed site-selective C7-functionalization of indoles: advancement and future prospects

Chemical Communications, Год журнала: 2018, Номер 55(5), С. 572 - 587

Опубликована: Дек. 5, 2018

C7-Decorated indoles are important structural motifs present in a plethora of bioactive and pharmaceutical compounds. Early stage developments for C7 modifications were realized through directed metallation (DOM) subsequent quenching with suitable electrophiles or by halogenation Cu(ii) halides. Direct C-7 functionalization is comparatively difficult compared to at C-2 C-3 positions owing the inherent reactivity pyrrole-type ring. However, recently transition-metal-catalyzed auxiliary assisted site-selective has emerged as an elegant synthetic tool carbon-carbon carbon-heteroatom bond formation diversify indoles. This article covers advancement, application mechanistic underpinnings evolved transformations otherwise inert C7-H up October 2018.

Язык: Английский

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Application of Palladium-Catalyzed C(sp2)–H Bond Arylation to the Synthesis of Polycyclic (Hetero)Aromatics

Chem, Год журнала: 2019, Номер 5(8), С. 2006 - 2078

Опубликована: Июль 3, 2019

Язык: Английский

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Biomass-Derived Solvents for Sustainable Transition Metal-Catalyzed C–H Activation

ACS Sustainable Chemistry & Engineering, Год журнала: 2019, Номер 7(9), С. 8023 - 8040

Опубликована: Март 29, 2019

Transition metal-catalyzed C–H activation has emerged as an increasingly powerful strategy in molecular syntheses and a particularly attractive alternative to classical methods of cross-couplings. During the recent years, significant focus been dedicated further improve sustainable nature approach. As solvents represent major portion organic pollution caused by chemical syntheses, range nontoxic, biobased, have developed substitute for common reaction media. In this review, we present general perspective biomass-derived transition reactions their unique potential up January 2019.

Язык: Английский

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Rhodium(iii)-catalyzed C–H activation at the C4-position of indole: switchable hydroarylation and oxidative Heck-type reactions of maleimides

Chemical Communications, Год журнала: 2018, Номер 54(79), С. 11200 - 11203

Опубликована: Янв. 1, 2018

A Rh(iii)-catalyzed C–H activation of indole at the C4-position leading to novel and switchable functionalization has been reported by employing a weakly co-ordinating COCF₃ group as directing group.

Язык: Английский

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Mechanochemical Solvent‐Free Catalytic C−H Methylation

Angewandte Chemie International Edition, Год журнала: 2020, Номер 60(12), С. 6660 - 6666

Опубликована: Окт. 8, 2020

The mechanochemical, solvent-free, highly regioselective, rhodium-catalyzed C-H methylation of (hetero)arenes is reported. reaction shows excellent functional-group compatibility and demonstrated to work for the late-stage biologically active compounds. method requires no external heating benefits from considerably shorter times than previous solution-based protocols. Additionally, mechanochemical approach shown enable efficient synthesis organometallic complexes that are difficult generate conventionally.

Язык: Английский

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