Site-selective C–H functionalization to access the arene backbone of indoles and quinolines

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(20), P. 11249 - 11269

Published: Jan. 1, 2021

The site-selective C-H bond functionalization of heteroarenes can eventually provide chemists with great techniques for editing and building complex molecular scaffolds. During the past decade, benzo-fused N-heterocycles such as indoles quinolines have been among most widely investigated organic templates. Early developments led to on pyrrole pyridine cores quinolines; however, benzenoid ring has remained a challenge in catalysis. In this review, we elaborate recent highly challenging bonds less-reactive core quinolines. These findings are mainly described selective directing group assisted strategies, remote their reaction mechanisms. underlying principle each strategy is elucidated, which aims facilitate design more advanced structure heterocycles based bioactive molecules, synthetic drugs, material aspects. Moreover, challenges perspectives catalytic access arene backbone also proposed conclusion section.

Language: Английский

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Regioselective C₃Alkylation of Indoles for the Synthesis of Bis(indolyl)methanes and 3-Styryl Indoles

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(3), P. 1846 - 1857

Published: Jan. 12, 2024

Herein, we describe an efficient transition-metal-free regioselective C3alkylation of indoles for the synthesis bis(indolyl)methanes and 3-styryl indoles. Nitrobenzene is employed as oxidant to oxidize alcohols in presence a strong base reaction avoids use transition metals such Ru Mn. The protocol provides favorable route access biologically active compounds arundine, vibrindole A, turbomycin B.

Language: Английский

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Transition metal-catalyzed C–H functionalizations of indoles

New Journal of Chemistry, Journal Year: 2021, Volume and Issue: 45(31), P. 13692 - 13746

Published: Jan. 1, 2021

This review summarises a wide range of transformations on the indole skeleton, including arylation, alkenylation, alkynylation, acylation, nitration, borylation, and amidation, using transition-metal catalyzed C–H functionalization as key step.

Language: Английский

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Synthesis of C‐Aryl Glycosides by C−H Functionalization

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(32)

Published: March 21, 2023

Abstract In recent years, the synthesis of C‐aryl glycosides hrough C−H functionalization has attracted extensive attention organic chemists due to its steps and atomic economy. this concept, we systematically summarizes with diverse regioselectivity diastereoselectivity from perspective arylation glycosylation arenes. It can be found that a series recently developed reactions have higher site‐selectivity diastereomeric selectivity than Friedel–Crafts reaction. The reaction conditions are milder, which compatible acid‐sensitive protective groups, such as acetals or ketals, deprotection is more convenient. seen there few reports on remote aromatic hydrocarbons, new field needs further research. addition, lot shortcomings, need explored: a) precise regulation stereoselectivity in process also optimization; b) research mechanism almost limited DFT calculation, no exact experimental evidence. For key parts, specific between cyclo‐metal intermediates glycosyl donors ortho ‐C Ar −H still unclear; c) fact aryl glycoside compounds contain bare hydroxyl groups practical applications, it an urgent problem realize compatibility substrates containing naked remove by mild efficient method after reaction; d) rapidly developing field, study greener, economical arenes future, will conducive biological application significance.

Language: Английский

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Enabling Cyclopropanation Reactions of Imidazole Heterocycles via Chemoselective Photochemical Carbene Transfer Reactions of NHC-Boranes

Organic Letters, Journal Year: 2022, Volume and Issue: 24(11), P. 2232 - 2237

Published: March 11, 2022

Herein we report a site-selective cyclopropanation of N-heterocyclic carbene (NHC)-borane complexes via photochemical transfer reactions. By subtle changes to the reaction conditions, this approach can be further extended toward difunctionalization NHC-boranes and B-H insertion reaction. Further investigations in continuous-flow applications synthetic transformations proved utility method. Theoretical calculations control experiments were performed explain observed selectivity.

Language: Английский

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Recent Advances on Direct Functionalization of Indoles in Aqueous Media

The Chemical Record, Journal Year: 2023, Volume and Issue: 23(3)

Published: Feb. 1, 2023

Abstract Indoles and their derivatives have dominated a significant proportion of nitrogen‐containing heterocyclic compounds play an essential role in synthetic medicinal chemistry, pesticides, advanced materials. Compared with conventional strategies, direct functionalization indoles provides straightforward access to construct diverse indole scaffolds. As we enter era emphasizing green sustainable utilizing environment‐friendly solvents represented by water demonstrates great potential synthesizing valuable derivatives. This review aims depict the critical aspects aqueous‐mediated over past decade discusses future challenges prospects this fast‐growing field. For convenience readers, is classified into three parts according bonding modes (C−C, C−N, C−S bonds), which focus on diversity derivatives, prominent chemical process, types catalyst systems mechanisms. We hope can promote development discovery novel practical organic methods aqueous phase.

Language: Английский

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Ynones in dearomative spirocyclisation processes; a review

Tetrahedron Chem, Journal Year: 2024, Volume and Issue: 9, P. 100055 - 100055

Published: Jan. 14, 2024

This review concentrates on our research into the discovery of novel ynone-based dearomative spirocyclisation processes, whilst placing new chemistry context existing knowledge. The genesis programme, development efficient synthetic routes to prepare natural products spirobacillene A (1) and B (2), utilised indole ynones. stimulated a much wider study explore reactivity ynones in processes more generally. Routes generate wide range spirocycles were subsequently developed, with reactions tethered indoles, benzofurans, benzisoxazoles, pyrroles, pyridines, isoquinolines, pyrazines, cyclic ketimines, anisoles all discussed herein, these initiated by catalytic Ag(I), Cu(II), Pd(0), photolysis many other reagents. Asymmetric variants some are also discussed, as is further elaboration spirocyclic give carbazoles, quinolones, polycycles useful building blocks. Finally, applications methodology product synthesis (e.g. A, lasubine II indolizidine 209D) described.

Language: Английский

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Dearomative [4 + 2] cycloaddition of 3‐nitroindoles with ortho‐amino Morita−Baylis−Hillman carbonates to forge indole‐fused quinolines

Journal of Heterocyclic Chemistry, Journal Year: 2024, Volume and Issue: 61(3), P. 528 - 537

Published: Jan. 16, 2024

Abstract A dearomative [4 + 2] cycloaddition of 3‐nitroindoles ortho ‐amino Morita−Baylis−Hillman carbonates was established under mild conditions. This method provides an efficient and practical approach for delivering tetrahydro‐5 H ‐indolo[2,3‐ b ]quinolines containing three contiguous stereocenters, two tertiary one quaternary, in high yield (up to 95%) with excellent diastereoselectivity (all cases >25:1 dr ). The potential synthetic applications this strategy were also highlighted by the scale‐up experiment further transformation. Moreover, structure relative configuration cycloadduct unequivocally confirmed single‐crystal X‐ray diffraction.

Language: Английский

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Iodine-mediated oxidative triple functionalization of indolines with azoles and diazonium salts

Chemical Communications, Journal Year: 2024, Volume and Issue: 60(34), P. 4613 - 4616

Published: Jan. 1, 2024

We report an innovative synthetic strategy for the generation of polysubstituted indoles from indolines, aryldiazonium salts, and azoles. The methodology encompasses electrophilic substitution reaction affording C5-indoline intermediates which undergo iodine-mediated oxidative transformation coupled with C-H functionalization to yield indole derivatives.

Language: Английский

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Recent Progress in Gold‐Catalyzed Reactions of Alkynes for the Construction of Indole Frameworks

Asian Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 12(8)

Published: June 21, 2023

Abstract Indole heterocycles hold an important position in chemical landscape because of their prominence natural products and pharmaceuticals. Consequently, development new efficient strategies to access indole scaffold are continuous interest. For the past few years, gold‐catalyzed activation alkyne has emerged as a powerful strategy for constructing heterocyclic skeleton. The present review highlights recent advances (2018–2023) toward synthesis skeletons via annulations alkynes. A variety alkynes, such as, ynamides, azido ortho ‐alkynyl anilines, propargylic alcohols, phenylimines, miscellaneous alkynes employed affording various architectures under gold catalysis. Moreover, mechanisms included most cases better understanding reaction pathway.

Language: Английский

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