Hydroformylation of pyrolysis oils to aldehydes and alcohols from polyolefin waste

Science, Год журнала: 2023, Номер 381(6658), С. 660 - 666

Опубликована: Авг. 10, 2023

Waste plastics are an abundant feedstock for the production of renewable chemicals. Pyrolysis waste produces pyrolysis oils with high concentrations olefins (>50 weight %). The traditional petrochemical industry uses several energy-intensive steps to produce from fossil feedstocks such as naphtha, natural gas, and crude oil. In this work, we demonstrate that oil can be used aldehydes through hydroformylation, taking advantage olefin functionality. These then reduced mono- dialcohols, oxidized dicarboxylic acids, or aminated diamines by using homogeneous heterogeneous catalysis. This route high-value oxygenated chemicals low-value postconsumer recycled polyethylene. We project produced could lower greenhouse gas emissions ~60% compared their petroleum feedstocks.

Язык: Английский

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Anti-Markovnikov Intermolecular Hydroamination of Alkenes and Alkynes: A Mechanistic View

Chemical Reviews, Год журнала: 2023, Номер 123(15), С. 9139 - 9203

Опубликована: Июль 5, 2023

Hydroamination, the addition of an N–H bond across a C–C multiple bond, is reaction with great synthetic potential. Important advances have been made in last decades concerning catalysis these reactions. However, controlling regioselectivity amine toward formation anti-Markovnikov products (addition to less substituted carbon) still remains challenge, particularly intermolecular hydroaminations alkenes and alkynes. The goal this review collect systems which hydroamination terminal alkynes has achieved. focus will be placed on mechanistic aspects such reactions, discern step at decided unravel factors that favor regioselectivity. In processes entailing direct alternative pathways, involving several reactions accomplish (formal processes), also discussed review. catalysts gathered embrace most metal groups Periodic Table. Finally, section discussing radical-mediated metal-free approaches, as well heterogeneous catalyzed processes, included.

Язык: Английский

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Cobalt-catalyzed synthesis of amides from alkenes and amines promoted by light

Science, Год журнала: 2024, Номер 383(6678), С. 77 - 81

Опубликована: Янв. 4, 2024

Catalytic methods to couple alkene and amine feedstocks are valuable in synthetic chemistry. The direct carbonylative coupling of alkenes amines holds promise as a perfectly atom-economical approach amide synthesis, but general remain underdeveloped. Herein, we report an hydroaminocarbonylation catalyzed by unmodified, inexpensive cobalt carbonyl under mild conditions low pressure promoted light. Silane addition after the reaction enables sequential cobalt-catalyzed reduction, constituting formal hydroaminomethylation. These exhibit exceptional scope across both components with high chemo- regioselectivity proceed efficiently even absence solvent. formation hydridocobalt through photodissociation ligand is proposed enable catalytic activity conditions, which addresses long-standing challenge catalysis.

Язык: Английский

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An unprecedented 2-fold interpenetrated open framework built from Zn6 ring seamed trivacant polyoxotungstates used for photocatalytic synthesis of pyridine derivatives

Applied Catalysis B Environment and Energy, Год журнала: 2022, Номер 323, С. 122134 - 122134

Опубликована: Ноя. 1, 2022

Язык: Английский

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Remote and Proximal Hydroaminoalkylation of Alkenes Enabled by Photoredox/Nickel Dual Catalysis

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(39), С. 17776 - 17782

Опубликована: Сен. 22, 2022

A mild and site-selective hydroaminoalkylation of activated unactivated alkenes via dual photoredox/Ni catalysis is developed. This catalytic strategy enables exclusive access to α-selective products, which complementary previously reported photocatalytic that provides the β-selective products. The chain-walking a Ni–H intermediate toward carbonyl allows for at remote sp3 C–H sites. method tolerates broad substrate scope both amines as well providing streamlined synthesis value-added β-amino acid derivatives from readily available starting materials.

Язык: Английский

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Nickel/Photoredox Dual-Catalyzed Regiodivergent Aminoalkylation of Unactivated Alkyl Halides

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(42), С. 23385 - 23394

Опубликована: Окт. 12, 2023

A mild and regiodivergent aminoalkylation of unactivated alkyl halides is disclosed via a dual photoredox/nickel catalysis. Bipyridyl-type ligands without an ortho-substituent control the site-selective coupling at original position, while ortho-disubstituted tune site-selectivity remote, unprefunctionalized position. Mechanistic studies combined with DFT calculations give insight into mechanism origins ligand-controlled regioselectivity. Notably, this redox-neutral, alkyl-alkyl features conditions, broad substrate scope for both partners, excellent offers straightforward way α-alkylation tertiary amines to synthesize structurally diverse alkylamines value-added amino acid derivatives.

Язык: Английский

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Organocatalytic radical relay trifunctionalization of unactivated alkenes by a combination of cyano migration and alkylacylation

Chemical Communications, Год журнала: 2023, Номер 59(36), С. 5395 - 5398

Опубликована: Янв. 1, 2023

The first N-heterocyclic carbene organocatalytic three-component radical relay trifunctionalization of unactivated alkenes through the combination remote 1,4-cyano migration and alkylacylation was reported. This protocol features mild reaction conditions, readily available materials, excellent regioselectivity, capability late-stage functionalization.

Язык: Английский

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Ligand-Controlled Regiodivergent Nickel-Catalyzed Hydroaminoalkylation of Unactivated Alkenes

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(5), С. 3458 - 3470

Опубликована: Янв. 25, 2024

Ligand modulation of transition-metal catalysts to achieve optimal reactivity and selectivity in alkene hydrofunctionalization is a fundamental challenge synthetic organic chemistry. Hydroaminoalkylation, an atom-economical approach for alkylating amines using alkenes, particularly significant amine synthesis the pharmaceutical, agrochemical, fine chemical industries. However, existing methods usually require specific substrate combinations precise regio- stereoselectivity, which limits their practical utility. Protocols allowing regiodivergent hydroaminoalkylation from same starting materials, controlling both regiochemical stereochemical outcomes, are currently absent. Herein, we report ligand-controlled, nickel-catalyzed unactivated alkenes with

Язык: Английский

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Tailored Amine Oxides─Synergists, Surfactants, and Polymers for Gas Hydrate Management, a Minireview

Energy & Fuels, Год журнала: 2023, Номер 37(13), С. 8919 - 8934

Опубликована: Июнь 27, 2023

Low-dosage hydrate inhibitors (LDHIs) are used to prevent gas hydrates from plugging upstream and oil flow lines. LDHIs come in two main classes, kinetic (KHIs) anti-agglomerants (AAs). KHIs delay the formation process, while AAs ultimately disperse any formed so that no deposits or plugs formed. Currently, KHI formulations deployed field contain one more water-soluble polyamides with optimized hydrophobic groups, most commercialized cationic quaternary ammonium surfactants also groups. The amine oxide group is closely related salts but has zero overall charge amide as a result of strong hydrogen-bonding properties. In past decade, small oxides synergists, polyamine stand-alone KHIs, have all been developed. This review summarizes contributions development amine-oxide-based LDHIs. includes powerful monoamine synergists for polyamide high-salinity-compatible bis-amine function both AAs.

Язык: Английский

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Iridium‐Catalyzed Remote Site‐Switchable Hydroarylation of Alkenes Controlled by Ligands

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(41)

Опубликована: Авг. 23, 2023

An iridium-catalyzed remote site-switchable hydroarylation of alkenes was reported, delivering the products functionalized at subterminal methylene and terminal methyl positions on an alkyl chain controlled by two different ligands, respectively, in good yields with to excellent site-selectivities. The catalytic system showed functional group tolerance a broad substrate scope, including unactivated activated alkenes. More importantly, regioconvergent transformations mixtures isomeric were also successfully realized. results mechanistic studies demonstrate that reaction undergoes chain-walking process give [Ar-Ir-H] complex alkene. subsequent processes proceed through modified Chalk-Harrod-type mechanism via migratory insertion alkene into Ir-C bond followed C-H reductive elimination afford hydrofunctionalization site-selectively.

Язык: Английский

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