Enantioselective Radical Reactions Using Chiral Catalysts

Chemical Reviews, Год журнала: 2022, Номер 122(6), С. 5842 - 5976

Опубликована: Янв. 24, 2022

Benefiting from the impressive increase in fundamental knowledge, last 20 years have shown a continuous burst of new ideas and consequently plethora catalytic methods for enantioselective radical reactions. This review aims to provide complete survey progress achieved over this latter period. The first part focuses on use chiral organocatalysts, these include catalysts covalently linked substrate those that interact with by weaker interactions like hydrogen bonds. second is devoted transition-metal redox catalysis which organized according increasing atomic number first-row transition metals (Ti, Cr, Fe, Mn, Co, Ni, Cu). Bioinspired manganese- iron-mediated hydroxylations oxidations are also discussed. A specific section dedicated reactivity Ru, Rh, Ir complexes as Lewis acids special focus at metal. Absorption photons result different events such energy transfer, single-electron hydrogen-atom transfer facilitating formation radicals. Organocatalysis has been successfully combined photocatalysts, opened pathways enlarging precursors available. merger photocatalysis organo- or metalla-photocatalysis brought novelty allowed discovery large original transformations. enzyme-catalyzed reactions involving intermediates largely benefit visible-light irradiation included review. provides comprehensive inventory goal detailing reaction mechanisms involved transformations any nonspecialist could find their own creativity invent yet unknown applications.

Язык: Английский

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Ligand‐to‐Metal Charge Transfer (LMCT) Photochemistry at 3d‐Metal Complexes: An Emerging Tool for Sustainable Organic Synthesis

ChemCatChem, Год журнала: 2022, Номер 14(19)

Опубликована: Авг. 11, 2022

Abstract Despite the rich photochemistry of 3d‐metal complexes, utilization excited‐state reactivity these compounds in organic synthesis has been historically overlooked. The advent photoredox catalysis changed perception synthetic chemists towards photochemistry, and nowadays potential photoinduced, outer‐sphere single‐electron transfer events is widely recognized. More recently, an emerging new mode photoactivation taken spotlight, based on inner‐sphere triggered by population ligand‐to‐metal charge‐transfer (LMCT) excited states. Contrarily to photoredox, LMCT‐activation does not rely matching redox potentials, offers unique profiles particularly well suited Earth‐abundant metal complexes. Those appealing features are propelling development methods using this blueprint generate highly reactive open‐shell species under mild conditions. aim contribution provide a didactical tool for comprehension concept facilitate methodologies achieve sustainable chemical transformations.

Язык: Английский

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Asymmetric hydrogenation catalyzed by first-row transition metal complexes

Chemical Society Reviews, Год журнала: 2021, Номер 50(5), С. 3211 - 3237

Опубликована: Янв. 1, 2021

This review focuses on asymmetric direct and transfer hydrogenation with first-row transition metal complexes. The reaction mechanisms the models of enantiomeric induction were summarized emphasized.

Язык: Английский

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Reductive Deoxygenative Functionalization of Alcohols by First‐Row Transition Metal Catalysis

Chinese Journal of Chemistry, Год журнала: 2023, Номер 41(13), С. 1637 - 1652

Опубликована: Янв. 23, 2023

Comprehensive Summary Alcohols are among the most accessible functionalities. Catalytic deoxygenative functionalization of alcohols is highly synthetically appealing. While significant progress has been made on reactions with nucleophiles, electrophilic coupling partners remain a real challenge. This manuscript highlights advance in this direction, which mainly achieved by first‐row transition metals. The low‐valent titanium catalyst shown unique reactivity to homolytically cleave C—OH bonds. formed carbon radicals could either undergo reduction give protonation products or couple fragments form C—C chemistry initially realized using stoichiometric amount reagents and later extended catalytic variants. Nickel features variety oxidation states ranging from Ni 0 IV , both two‐electron oxidative addition single‐electron process involved their activation an electrophile. These properties enable nickel catalyze reductive R–X electrophiles. reaction first reported allylic alcohols, then benzylic and, very recently non‐activated alcohols. Recent effort resulted many invaluable methodologies that improve efficiency for construction aliphatic use cobalt copper catalysts not only expands substrate scope these but also shows new selectivity issues.

Язык: Английский

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Constructing of ultrathin Bi2WO6/BiOCl nanosheets with oxygen vacancies for photocatalytic oxidation of cyclohexane with air in solvent-free

Applied Surface Science, Год журнала: 2022, Номер 584, С. 152606 - 152606

Опубликована: Янв. 28, 2022

Язык: Английский

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Titanium radical redox catalysis: Recent innovations in catalysts, reactions, and modes of activation

Chem, Год журнала: 2022, Номер 8(7), С. 1805 - 1821

Опубликована: Июль 1, 2022

Radical chemistry has emerged as a cornerstone in modern organic synthesis, providing chemists with numerous new tools to rapidly expand reactivity and chemical space academic industrial research. In this regard, titanium complexes have been recognized an attractive class of catalysts owing their rich redox activities addition the abundance low toxicity early transition metal. Traditionally employed for activation epoxides carbonyl compounds, Ti radical catalysis broken into grounds recent years, giving rise diverse repertoire useful transformations. Perspective, we highlight developments area

Язык: Английский

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Complex Nanomaterials in Catalysis for Chemically Significant Applications: From Synthesis and Hydrocarbon Processing to Renewable Energy Applications

Advances in Materials Science and Engineering, Год журнала: 2022, Номер 2022, С. 1 - 72

Опубликована: Фев. 8, 2022

The world is rapidly changing, the resources are getting depleted, and demand for newer technologies products increasing. To keep up with these new advances, highly efficient catalytic routes need to be taken sustainable ensure a drawn-out existence of future generations. Catalysis turns out significantly important field application when it comes era nanoscience, where all devices becoming smaller in size improved properties. When deeming usability catalyst, paramount importance have good understanding their properties synergistic effect on other reagents reaction. Over last decade, nanocatalysis has grown rapidly, both homogeneous heterogeneous catalysis. Given that nanoparticles high surface-to-volume ratio compared bulk materials, they appealing as catalysts. Catalysts accelerate boost thousands different chemical reactions daily basis, forming foundation multibillion-dollar industry worldwide, pathway leading green chemistry, novel, yet crucial, environmental protection technology. As result, this review, use nanocatalysts special features renewable energy, hydrocarbon processing, fine synthesis sector was explored. A detailed explanation working mechanism nanocatalysts, starting from how synthesized modification surface, been put together. We tried collect current progresses three sectors best our abilities. Furthermore, anticipated paper would useful researchers academicians wishing contribute toward subject interest.

Язык: Английский

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Hydroaminoalkylation for the Catalytic Addition of Amines to Alkenes or Alkynes: Diverse Mechanisms Enable Diverse Substrate Scope

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(26), С. 11459 - 11481

Опубликована: Июнь 22, 2022

Hydroaminoalkylation is a powerful, atom-economic catalytic reaction for the of amines with alkenes and alkynes. This C–H functionalization allows alkylation using simple or alkynes as alkylating agents. transformation has significant potential transformative approaches in pharmaceutical, agrochemical, fine chemical industries preparation selectively substituted N-heterocycles shows promise materials science synthesis functional responsive aminated materials. Different early transition-metal, late photoredox catalysts mediate hydroaminoalkylation by distinct mechanistic pathways. These insights have resulted development new conditions to realize broad range substrates: activated unactivated, terminal internal, C–C double triple bonds aryl alkyl primary, secondary, tertiary amines, including N-heterocyclic amines. By deploying select specific substrate combinations, control over regioselectivity, diastereoselectivity, enantioselectivity been realized. Key barriers widespread adoption this include air moisture sensitivity transition-metal well heavy dependence on amine protecting directing groups photocatalytic routes. Advances improved catalyst robustness, scope, regio-/stereoselective reactions early- catalysts, catalysis, are highlighted, opportunities further included. perspective that be disruptive strategy from alkenes.

Язык: Английский

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Pd-Catalyzed Cross-Couplings: On the Importance of the Catalyst Quantity Descriptors, mol % and ppm

Organic Process Research & Development, Год журнала: 2022, Номер 26(8), С. 2240 - 2269

Опубликована: Июль 11, 2022

This Review examines parts per million (ppm) palladium concentrations in catalytic cross-coupling reactions and their relationship with mole percentage (mol %). Most studies chemistry have historically focused on the concentration ratio between (pre)catalyst limiting reagent (substrate), expressed as mol %. Several recent papers outlined use of "ppm level" an alternative means describing reaction systems. led us to delve deeper into literature assess whether is a practically useful descriptor catalyst quantities palladium-catalyzed reactions. Indeed, we conjectured that many could, unknowingly, employed low levels" (pre)catalyst, generally, what would spread ppm look like across selection reported vast array literature. In few selected examples, examined other metal systems for comparison palladium.

Язык: Английский

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Direct and Unified Access to Carbon Radicals from Aliphatic Alcohols by Cost‐Efficient Titanium‐Mediated Homolytic C−OH Bond Cleavage

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(10)

Опубликована: Янв. 11, 2022

Low-valent Ti-mediated homolytic C-O bond cleavage offers unified access to carbon radicals from ubiquitous non-activated tertiary, secondary, and even primary alcohols. In contrast the representative Ti reagents, which were ineffective for this purpose, "TiCl2 (cat)"/Zn (cat=catecholate) was found be specifically active. This method applied addition reactions of alkenes exhibited high generality yields. More than 50 combinations examined. The excellent cost-efficiency accessibility further enhance its applicability. Control experiments proved presence a radical intermediate excluded pathway via alkyl chlorides. Further mechanistic study indicated that 1 : 2 complex alkoxide (R-O- ) TiIII is an active species in cleavage.

Язык: Английский

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