Challenges and Opportunities in Multicatalysis

ACS Catalysis, Год журнала: 2021, Номер 11(7), С. 3891 - 3915

Опубликована: Март 15, 2021

Multicatalysis is an emerging field targeting the development of efficient catalytic transformations to quickly convert relatively simple starting materials into more complex value-added products. Within multicatalytic processes either multiple catalysts execute single reactions or precise sequences occur in a "one-pot" fashion. Attractively, protocols not only enable that are inaccessible through classic approaches but also able significantly reduce time, waste, and cost synthetic processes, making organic synthesis resources efficient. In this Perspective article, we review different strategies multicatalysis bring distinct challenges opportunities. We divide overarching three main categories: cooperative, domino, relay catalysis. Each category described along with representative examples highlight its features. Special emphasis dedicated catalysis, which further discussed subcategories. Lastly, provide analysis systems incorporate higher levels complexity underscore potential systems.

Язык: Английский

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Cobalt-Catalyzed Enantioselective C–H Arylation of Indoles

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(2), С. 798 - 806

Опубликована: Янв. 10, 2022

Atropoisomeric (hetero)biaryls are scaffolds with increasing importance in the pharmaceutical and agrochemical industries. Although it is most obvious disconnection to construct such compounds, direct enantioselective C–H arylation through concomitant induction of chiral information remains extremely challenging uncommon. Herein, unprecedented earth-abundant 3d-metal-catalyzed atroposelective reported, furnishing rare atropoisomeric C2-arylated indoles. Kinetic studies DFT computation revealed an uncommon mechanism for this asymmetric transformation, oxidative addition being rate- enantio-determining step. Excellent stereoselectivities were reached (up 96% ee), while using unusual N-heterocyclic carbene ligand bearing essential remote substituent. Attractive dispersion interactions along positive C–H---π exerted by identified as key factors guarantee excellent enantioselection.

Язык: Английский

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Transition-metal-catalyzed C–H bond alkylation using olefins: recent advances and mechanistic aspects

Chemical Society Reviews, Год журнала: 2022, Номер 51(17), С. 7358 - 7426

Опубликована: Янв. 1, 2022

Transition metal catalysis has contributed immensely to C-C bond formation reactions over the last few decades, and alkylation is no exception. The superiority of such methodologies traditional evident from minimal reaction steps, shorter times, atom economy while also allowing control regio- stereo-selectivity. In particular, hydrocarbonation alkenes grabbed increased attention due its fundamental ability effectively selectively synthesise a wide range industrially pharmaceutically relevant moieties. This review attempts provide scientific viewpoint systematic analysis recent developments in transition-metal-catalyzed various C-H bonds using simple activated olefins. key features mechanistic studies involved these transformations are described briefly.

Язык: Английский

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Enantio‐ and Regioselective Electrooxidative Cobalt‐Catalyzed C−H/N−H Annulation with Alkenes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(11)

Опубликована: Янв. 20, 2023

In recent years, the merging of electrosynthesis with 3d metal catalyzed C-H activation has emerged as a sustainable and powerful technique in organic synthesis. Despite impressive advantages, development an enantioselective version remains elusive poses daunting challenge. Herein, we report first electrooxidative cobalt-catalyzed enantio- regioselective C-H/N-H annulation olefins using undivided cell at room temperature (up to 99 % ee). t Bu-Salox, rationally designed Salox ligand bearing bulky tert-butyl group ortho-position phenol, was found be crucial for this asymmetric reaction. A strong cooperative effect between Bu-Salox 3,4,5-trichloropyridine enabled highly more challenging α-olefins without secondary bond interactions 96 ee 97 : 3 rr). Cyclovoltametric studies, preparation, characterization, transformation cobaltacycle intermediates shed light on mechanism

Язык: Английский

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Palladium-catalyzed enantioselective carbonylation reactions

Science China Chemistry, Год журнала: 2022, Номер 65(3), С. 441 - 461

Опубликована: Янв. 5, 2022

Abstract Carbonylation, one of the most powerful approaches to preparation carbonylated compounds, has received significant attention from researchers active in various fields. Indeed, impressive progress been made on this subject over past few decades. Among types carbonylation reactions, asymmetric is a straightforward methodology for constructing chiral compounds. Although rhodium-catalyzed enantioselective hydroformylations have discussed several elegant reviews, general review palladium-catalyzed carbonylations still missing. In review, we summarize and discuss recent achievements reactions. Notably, review’s contents are categorized by reaction type.

Язык: Английский

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Base‐Promoted Electrochemical Co^II‐catalyzed Enantioselective C−H Oxygenation

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(21)

Опубликована: Март 20, 2023

Metalla-electrocatalyzed C-H oxygenation represents one of the most straightforward and sustainable approaches to access valuable oxygenated molecules. Despite significant advances, development enantioselective electrochemical reaction is very challenging remains elusive. Herein, we described first CoII -catalyzed alkoxylation. A broad range enantioenriched alkoxylated phosphinamides were obtained in good yields with excellent enantioselectivities (up 98 % yield >99 ee). An unusual cobalt(III) alcohol complex was prepared fully characterized, which proven be a key intermediate this alkoxylation reaction. Mechanistic studies revealed that oxidation CoIII CoIV facilitated by base whole process proceeded through cobalt(III/IV/II) catalytic cycle.

Язык: Английский

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Cobalt-Catalyzed Enantioselective C–H Annulation with Alkenes

ACS Catalysis, Год журнала: 2023, Номер 13(7), С. 4250 - 4260

Опубликована: Март 13, 2023

Herein, we disclose an efficient cobalt-catalyzed enantioselective C–H activation and annulation of benzamides with alkenes. This transformation is facilitated via the commercially available cobalt(II) catalyst in presence easily prepared chiral salicyl-oxazoline (Salox) ligand, which provides facile access to (R) or (S) enantiomers dihydroisoquinolone derivatives. It noticeable that reaction proceeded efficiently within extremely short time from 10 30 min under mild conditions. A broad range alkenes bear various functional substituents have been shown good compatibility deliver targeted products high yields enantioselectivities (51 examples, up 98% yield 99% ee). The gram scale experiment removal directing group further demonstrate practicability this protocol potential industrial applications. Density theory calculations elucidate mechanism, spin-state change olefin insertion step accelerates subsequent C–N reductive elimination, identified as stereo-determining step. AIM analysis indicates π interactions are vital for controlling switching stereoselectivity.

Язык: Английский

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P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis

Chemical Reviews, Год журнала: 2024, Номер 124(14), С. 8657 - 8739

Опубликована: Июль 2, 2024

Chiral phosphorus ligands play a crucial role in asymmetric catalysis for the efficient synthesis of useful optically active compounds. They are largely categorized into two classes: backbone chirality and P-stereogenic ligands. Most reported belong to former class. Privileged ones such as BINAP DuPhos frequently employed wide range catalytic transformations. In contrast, latter class has remained small family many years mainly because their synthetic difficulty. The late 1990s saw emergence novel with superior enantioinduction ability Rh-catalyzed hydrogenation reactions. Since then, numerous have been synthesized used This Review summarizes thus far, including stereochemical electronic properties that afford high excellent enantioselectivities. Examples reactions use this described together applications construction key intermediates natural products therapeutic agents. literature covered dates back 1968 up until December 2023, centering on studies published later years.

Язык: Английский

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Cobalt‐Catalyzed Enantioselective C−H Carbonylation towards Chiral Isoindolinones

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(10)

Опубликована: Янв. 11, 2024

Transition metal-catalyzed enantioselective C-H carbonylation with carbon monoxide, an essential and easily available C1 feedstock, remains challenging. Here, we disclosed unprecedented catalyzed by inexpensive readily cobalt(II) salt. The reactions proceed efficiently through desymmetrization, kinetic resolution, parallel affording a broad range of chiral isoindolinones in good yields excellent enantioselectivities (up to 92 % yield 99 ee). synthetic potential this method was demonstrated asymmetric synthesis biological active compounds, such as (S)-PD172938 (S)-Pazinaclone. resulting also serve ligands cobalt-catalyzed annulation alkynes construct phosphorus stereocenter.

Язык: Английский

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Cobalt(III)-Catalyzed Enantioselective C–H Functionalization: Ligand Innovation and Reaction Development

Accounts of Chemical Research, Год журнала: 2025, Номер unknown

Опубликована: Фев. 26, 2025

ConspectusIn contrast to precious transition metals, such as palladium and rhodium, the development of novel chiral ligands for enantioselective C-H functionalizations catalyzed by earth-abundant, cost-effective, environmentally friendly 3d metals poses substantial challenges, primarily due variable oxidation states, intricate coordination patterns, limited mechanistic insights. In this Account, we summarize our research endeavors in three types Co(III) catalysis: pseudotetrahedral achiral Cp*Co(III)/chiral carbonyl acid (CCA) catalysis, situ-generated octahedral cobalt(III) via cobalt/salicyloxazoline (Salox) Co(II)/chiral phosphoric (CPA) cooperative achieved through strategic ligand design. Our initial objective was achieve functionalization Cp*Co(III) catalysts with external ligands, aiming circumvent laborious preparation CpxCo(III) complexes. To end, developed several CCA incorporating non-covalent interactions (NCIs) a crucial design element. Next, address limitations associated lengthy synthesis Cp-ligated complexes difficulties modification, explored concept situ generation catalysis using commercially available cobalt(II) salts tailor-made ligands. This exploration led two innovative catalytic systems, namely, Co(II)/Salox Co(II)/CCA sequential catalysis. The emerged versatile strategy, demonstrating excellent enantioselectivities across range asymmetric reactions construct various molecules central, axial, planar, inherent chirality. facile single step, along ease further enhances versatility applicability approach. Moreover, successfully applied cobalt/Salox electro- photochemical-catalyzed functionalization, electrons or oxygen traceless oxidant, thereby eliminating need stoichiometric chemical oxidants. Through studies reaction developments, elucidated detailed structure-enantioselectivity relationships which are expected inform future endeavors. Finally, Co(II)/CPA enabled spiro-γ-lactams olefination/asymmetric [4 + 1] spirocyclization. Mechanistically, establishment stereochemistry occurs during cyclization where CPA serves both neutral Brønsted acid, stereoinduction independent cleavage step. We anticipate that insights advancements Account will inspire innovations drive progress metal-catalyzed reactions.

Язык: Английский

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