Iron-Catalyzed C(Sp³)–H Borylation, Thiolation, and Sulfinylation Enabled by Photoinduced Ligand-to-Metal Charge Transfer

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(13), С. 7600 - 7611

Опубликована: Март 23, 2023

Catalytic C(sp3)-H functionalization has provided enormous opportunities to construct organic molecules, facilitating the derivatization of complex pharmaceutical compounds. Within this framework, direct hydrogen atom transfer (HAT) photocatalysis becomes an appealing approach goal. However, viable substrates utilized in these protocols are limited, and site selectivity shows preference activated thermodynamically favored bonds. Herein, we describe development undirected iron-catalyzed borylation, thiolation, sulfinylation reactions enabled by photoinduced ligand-to-metal charge (LMCT) process. These exhibit remarkably broad substrate scope (>150 examples total), most importantly, all three show unconventional regioselectivity, with occurrence preferentially at distal methyl position. The procedures operationally simple readily scalable provide access high-value products from hydrocarbons one step. Mechanistic studies control experiments indicate that afforded is not only relevant HAT species but also largely affected use boron- sulfone-based radical acceptors.

Язык: Английский

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Resurgence and advancement of photochemical hydrogen atom transfer processes in selective alkane functionalizations

Chemical Science, Год журнала: 2023, Номер 14(25), С. 6841 - 6859

Опубликована: Янв. 1, 2023

The selective functionalization of alkanes has long been recognized as a prominent challenge and an arduous task in organic synthesis. Hydrogen atom transfer (HAT) processes enable the direct generation reactive alkyl radicals from feedstock have successfully employed industrial applications such methane chlorination process,

Язык: Английский

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Multiplicative enhancement of stereoenrichment by a single catalyst for deracemization of alcohols

Science, Год журнала: 2023, Номер 382(6669), С. 458 - 464

Опубликована: Окт. 26, 2023

Stereochemical enrichment of a racemic mixture by deracemization must overcome unfavorable entropic effects as well the principle microscopic reversibility; recently, photochemical reaction pathways unveiled energetic input light have led to innovations toward this end, most often ablation stereogenic C(sp3)-H bond. We report photochemically driven protocol in which single chiral catalyst two mechanistically different steps, C-C bond cleavage and formation, achieve multiplicative enhancement stereoinduction, leads high levels stereoselectivity. Ligand-to-metal charge transfer excitation titanium coordinated phosphoric acid or bisoxazoline efficiently enriches alcohols that feature adjacent fully substituted centers enantiomeric ratios up 99:1. Mechanistic investigations support pathway sequential radical-mediated scission formation through common prochiral intermediate reveal that, although overall stereoenrichment is high, selectivity each individual step moderate.

Язык: Английский

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Scalability of advanced oxidation processes (AOPs) in industrial applications: A review

Journal of Environmental Management, Год журнала: 2023, Номер 345, С. 118861 - 118861

Опубликована: Авг. 29, 2023

Disinfection and decontamination of water by application oxidisers is an essential treatment step across numerous industrial sectors including potable supply industry waste management, however, could be greatly enhanced if operated as advanced oxidation processes (AOPs). AOPs destroy contaminants pathogens uniquely harnessing radical chemistry. Despite offer great practical opportunities, no reviews to date have highlighted the critical AOP virtues that facilitate AOPs' scale up under growing demand. Hence, this review analyses parameters such oxidant conversion efficiency, batch mode vs continuous-flow systems, location production, delivery micro-/mesoporous structures process costs assist translation progressing developments into their large-scale applications. Additionally, state art analysed for various inducing radical/oxidiser measurement techniques half-lives with a view identify radicals/oxidisers are suitable in-situ production. It concluded radicals short hydroxyl (10-4 μsec) sulfate (30-40 need produced via reactors effective transport dosing. Meanwhile, longer ozone (7-10 min), hydrogen peroxide (stable several hours), hypochlorous acid (10 min -17 h) applied through reactor systems due relatively stability during transportation Complex costly synthesis well cytotoxicity many limit use in scaling AOPs, particularly immobilising delivering short-lived point Overall, using safe biocompatible structures, efficiency design portability priority areas development industry.

Язык: Английский

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Terminal C(sp ³ )–H borylation through intermolecular radical sampling

Science, Год журнала: 2024, Номер 383(6682), С. 537 - 544

Опубликована: Фев. 1, 2024

Hydrogen atom transfer (HAT) processes can overcome the strong bond dissociation energies (BDEs) of inert C(sp

Язык: Английский

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Site- and enantioselective allylic and propargylic C–H oxidation enabled by copper-based biomimetic catalysis

Nature Catalysis, Год журнала: 2025, Номер unknown

Опубликована: Янв. 8, 2025

Язык: Английский

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Copper-Mediated Dehydrogenative C(sp³)–H Borylation of Alkanes

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(28), С. 15207 - 15217

Опубликована: Июль 6, 2023

Borylations of inert carbon-hydrogen bonds are highly useful for transforming feedstock chemicals into versatile organoboron reagents. Catalysis these reactions has historically relied on precious-metal complexes, which promote dehydrogenative borylations with diboron reagents under oxidant-free conditions. Recently, photoinduced radical-mediated involving hydrogen atom transfer pathways have emerged as attractive alternatives because they provide complimentary regioselectivities and proceed metal-free However, net oxidative processes require stoichiometric oxidants therefore cannot compete the high economy their precious-metal-catalyzed counterparts. Herein, we report that CuCl2 catalyzes radical-mediated, C(sp3)-H alkanes bis(catecholato)diboron This is a result an unexpected dual role copper catalyst, promotes oxidation reagent to generate electrophilic bis-boryloxide acts effective borylating agent in subsequent redox-neutral photocatalytic C-H borylations.

Язык: Английский

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Photoelectrochemical oxidative C(sp3)−H borylation of unactivated hydrocarbons

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Окт. 16, 2023

Organoboron compounds are of high significance in organic synthesis due to the unique versatility boryl substituents access further modifications. The demand for incorporation moieties into molecular structures has witnessed significant progress, particularly C(sp3)-H borylation hydrocarbons. Taking advantage special characteristics photo/electrochemistry, we herein describe development an oxidative reaction under metal- and oxidant-free conditions, enabled by photoelectrochemical strategy. exhibits broad substrate scope (>57 examples), includes use simple alkanes, halides, silanes, ketones, esters nitriles as viable substrates. Notably, unconventional regioselectivity is achieved, with coupling site selectively located distal methyl group. Our method operationally easily scalable, offers a feasible approach one-step high-value organoboron building blocks from hydrocarbons, which would provide ample opportunities drug discovery.

Язык: Английский

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Efficient C(sp³)−H Carbonylation of Light and Heavy Hydrocarbons with Carbon Monoxide via Hydrogen Atom Transfer Photocatalysis in Flow**

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(36)

Опубликована: Июль 17, 2023

Abstract Despite their abundance in organic molecules, considerable limitations still exist synthetic methods that target the direct C−H functionalization at sp 3 ‐hybridized carbon atoms. This is even more case for light alkanes, which bear some of strongest bonds known Nature, requiring extreme activation conditions are not tolerant to most molecules. To bypass these issues, chemists rely on prefunctionalized alkyl halides or organometallic coupling partners. However, new regioselectively a variety different scaffolds would be great added value, only late‐stage biologically active molecules but also catalytic upgrading cheap and abundant hydrocarbon feedstocks. Here, we describe general, mild scalable protocol enables C(sp )−H carbonylation saturated hydrocarbons, including natural products using photocatalytic hydrogen atom transfer (HAT) gaseous monoxide (CO). Flow technology was deemed crucial enable high gas‐liquid mass rates fast reaction kinetics, needed outpace deleterious pathways, leverage safe process.

Язык: Английский

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Electrophotochemical Metal‐Catalyzed Enantioselective Decarboxylative Cyanation

Chemistry - A European Journal, Год журнала: 2023, Номер 29(24)

Опубликована: Янв. 13, 2023

Abstract In contrast to the rapid growth of electrophotocatalysis in recent years, enantioselective catalytic reactions powered by this unique methodology remain rare. work, we report an electrophotochemical metal‐catalyzed protocol for direct asymmetric decarboxylative cyanation aliphatic carboxylic acids. The synergistic merging cerium catalysis and electrochemical copper permits mild reaction conditions formation utilization key carbon centered radicals combining power light electrical energy. Electrophotochemical enables radical decarboxylation produce alkyl radicals, which could be effectively intercepted construction C−CN bonds a highly stereoselective fashion. This environmentally benign method smoothly converts diverse array arylacetic acids into corresponding nitriles good yields enantioselectivities without using chemical oxidants or pre‐functionalization acid substrates can readily scaled up.

Язык: Английский

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