Chemoselective Three‐Component Geminal Cross Couplings of Dihaloalkanes with Cr Catalysis: Rapid Access to Tertiary and Quaternary Alkanes via a Metal–Carbene Intermediate

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(44)

Опубликована: Сен. 14, 2023

Geminal cross couplings using multiple components enable the formation of several different bonds at one site in building tertiary and quaternary alkanes. Nevertheless, there are remaining issues concern-cleavage two geminal control selectivity present challenges. We report here three by reactions dihaloalkanes with organomagnesium chlorosilanes or alkyl tosylates Cr catalysis, affording C-C/C-Si C-C/C-C creation The catalyzed low-cost CrCl2 , enabling sluggishness competitive Kumada-type side homocouplings Grignard reagents, achieving high chemoselectivity. Experimental theoretical studies indicate that C-halide continuously cleaved to afford a metal carbene intermediate, which couples reagent, followed silylation, C-C C-Si via novel inner-sphere radical coupling mechanism. These three-component value-addition synthesis commercial drugs bioactive molecules medicinal chemistry.

Язык: Английский

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A four-component reaction to access 3,3-disubstituted indolines via the palladium–norbornene-catalyzed ortho amination/ipso conjunctive coupling

Chemical Science, Год журнала: 2023, Номер 15(4), С. 1318 - 1323

Опубликована: Дек. 14, 2023

As an important class of multicomponent reactions, the palladium/norbornene (Pd/NBE) cooperative catalysis has been mainly restricted to coupling aryl halide, electrophile and a nucleophile. Here, we report development Pd/NBE-catalyzed four-component reaction, which involves

Язык: Английский

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Metal-free and visible-light-mediated method enables the synthesis of olefins from ketones

Green Synthesis and Catalysis, Год журнала: 2024, Номер unknown

Опубликована: Фев. 1, 2024

Direct synthesis of olefins continues to attract stellar attention due the high importance olefins. In this context, wide availability ketones, directly from ketones provides a straightforward route. Considering this, via formation donor/donor type carbenes has been developed which leads efficient versatile by using metal-free strategy. This approach features mild reaction conditions and exhibits broad substrate scope when biomass-derived solvent as green media is used. The practical utility demonstrated late-stage modifications even scaling up 20 grams scale. At end, mechanistic investigations density functional theory studies clearly proved carbenes, examined necessity all reagents effect light in system.

Язык: Английский

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Copper‐Catalyzed 1,4‐Addition of a Silicon Nucleophile to Azadienes

European Journal of Organic Chemistry, Год журнала: 2023, Номер 26(16)

Опубликована: Март 13, 2023

Abstract Copper‐catalyzed 1,4‐addition of a silicon nucleophile to azadienes is reported. This method facilely provided wide variety dibenzylic silane derivatives in good excellent yields. The important practical features are the use cheap catalytic system, mild reaction conditions, and broad substrate scope.

Язык: Английский

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Enantioselective Synthesis of Dihydropyrazoles by Palladium/Xu‐Phos‐Catalyzed Alleneamination of β,γ‐Unsaturated Hydrazones with Propargylic Acetates

Angewandte Chemie, Год журнала: 2023, Номер 135(20)

Опубликована: Март 10, 2023

Abstract The palladium‐catalyzed asymmetric carboamination reaction is one of the most significant transformations in organic chemistry. Herein, we report first alleneamination β,γ ‐ unsaturated hydrazones with propargylic acetates. This protocol enables efficient installation various multisubstituted allene groups onto dihydropyrazoles good yields excellent enantioselectivities. chiral sulfinamide phosphine ligand Xu 5 exhibits highly stereoselective control this protocol. salient features include readily available starting materials, a broad substrate scope, an easy scale‐up, mild conditions and versatile transformations.

Язык: Английский

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Palladium-catalyzed intramolecular enantioselective C(sp³)–H insertion of donor/donor carbenes

Chemical Science, Год журнала: 2022, Номер 13(42), С. 12396 - 12402

Опубликована: Янв. 1, 2022

Herein, the first palladium-catalyzed intramolecular enantioselective C(sp

Язык: Английский

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Palladium‐Catalyzed Synthesis of Bicyclic Derivatives from the Cyclization/1,4‐Difunctionalization of Bromoarenes with Diazo Compounds

Asian Journal of Organic Chemistry, Год журнала: 2023, Номер 13(2)

Опубликована: Ноя. 28, 2023

Abstract A Pd‐catalyzed cyclization/1,4‐difunctionalization of bromoarenes bearing a carbon nucleophile with diazo compounds has been developed. The present reaction proceeds through π‐benzyl palladium intermediate, whose reactivity is key for the remarkable 1,4‐selectivity this reaction, providing functionalized indans and tetralins.

Язык: Английский

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Enantioselective and Regiodivergent Synthesis of Propargyl‐ and Allenylsilanes through Catalytic Propargylic C−H Deprotonation

Angewandte Chemie, Год журнала: 2024, Номер 136(16)

Опубликована: Фев. 13, 2024

Abstract We report a highly enantioselective intermolecular C−H bond silylation catalyzed by phosphoramidite‐ligated iridium catalyst. Under reagent‐controlled protocols, propargylsilanes resulting from C(sp 3 )−H functionalization, as well the regioisomeric and synthetically versatile allenylsilanes, could be obtained with excellent levels of enantioselectivity good to control propargyl/allenyl selectivity. In case unsymmetrical dialkyl acetylenes, selectivity for functionalization at less‐hindered site was also observed. A variety electrophilic silyl sources (R SiOTf R SiNTf 2 ), either commercial or in situ ‐ generated, were used reagents, broad range simple functionalized alkynes, including aryl alkyl 1,3‐enynes, drug derivatives successfully employed substrates. Detailed mechanistic experiments DFT calculations suggest that an η ‐propargyl/allenyl Ir intermediate is generated upon π‐complexation‐assisted deprotonation undergoes outer‐sphere attack silylating reagent give propargylic silanes, latter step identified enantiodetermining step.

Язык: Английский

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Synthesis of Organosilanes, Silyl Ethers, and Silanols

Elsevier eBooks, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

Язык: Английский

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Acetone Serving as a Solvent and Interaction Partner Promotes the Direct Olefination of N-Tosylhydrazones under Visible Light

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(9), С. 6180 - 6192

Опубликована: Апрель 18, 2024

The photochemistry of noncovalent interactions to promote organic transformations is an emerging approach providing fresh opportunities in synthetic chemistry. Generally, the external substance necessary add as interaction partner, thereby sacrificing atom economy reaction. Herein, we describe a catalyst-free and interaction-mediated strategy access olefination N-tosylhydrazones using acetone solvent partner. This protocol also features broad substrate scope, excellent functional group compatibility, mild reaction conditions without transition metals. Moreover, gram-scale synthesis olefins generation pharmaceutical intermediates highlighted its practical applicability. Lastly, mechanistic studies indicate that was initiated via between N-tosylhydrazone anion, which supported by density theory calculations.

Язык: Английский

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