Highly Regio- and Enantioselective Reductive Coupling of Alkynes and Aldehydes via Photoredox Cobalt Dual Catalysis

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(19), С. 7306 - 7313

Опубликована: Май 5, 2021

A Co-catalyzed highly regio- and enantioselective reductive coupling of alkynes aldehydes has been developed under visible light photoredox dual catalysis. variety enantioenriched allylic alcohols have obtained by using unsymmetrical internal commercially available catalyst, chiral ligand, reagents. It is noteworthy that this approach considerable advantages, such as excellent (>95:5 for >40 examples), stereo- (up to >95:5 E/Z), enantioselectivity (92-99% ee, >35 examples) control, mild reaction conditions, broad substrate scope, good functional group compatibility, making it a great improvement alkyne-aldehyde reactions.

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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A New Paradigm in Enantioselective Cobalt Catalysis: Cationic Cobalt(I) Catalysts for Heterodimerization, Cycloaddition, and Hydrofunctionalization Reactions of Olefins

Accounts of Chemical Research, Год журнала: 2021, Номер 54(24), С. 4545 - 4564

Опубликована: Ноя. 30, 2021

One of the major challenges facing organic synthesis in 21st century is utilization abundantly available feedstock chemicals for fine chemical synthesis. Regio- and enantioselective union easily accessible 1,3-dienes other feedstocks like ethylene, alkyl acrylates, aldehydes can provide valuable building blocks adorned with latent functionalities further synthetic elaboration. Through an approach that relies on mechanistic insights systematic examination ligand counterion effects, we developed efficient cobalt-based catalytic system [(P∼P)CoX2/Me3Al] (P∼P = bisphosphine) to effect first heterodimerization several types ethylene. In addition simple cyclic acyclic dienes, siloxy-1,3-dienes participate this reaction, giving highly functionalized, nearly enantiopure silyl enolates, which be used subsequent C-C C-X bond-forming reactions. As our understanding mechanism reaction improved, attention was drawn more challenging partners acrylates (one largest volume feedstocks) as olefin instead Prompted by intrinsic limitations using aluminum alkyls activators explored fundamental chemistry lesser known (P∼P)Co(I)X species discovered presence halide sequestering agents, such sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (NaBARF) or (C6F5)3B, certain chiral bisphosphine complexes are superb catalysts regio- acrylates. We have since found these cationic Co(I) catalysts, most conveniently prepared situ reduction corresponding cobalt(II) zinc NaBARF, promote [2 + 2]-cycloaddition between alkynes astonishing variety alkenyl derivatives give functionalized cyclobutenes. reactions 1,3-enynes alkyne ethylene followed a 1,4-addition tandem fashion cyclobutanes all-carbon quaternary center, set molecules maps well into many medicinally relevant compounds. another application, find Co(I)-catalysts selective hydroacylation 1,2-hydroboration prochiral 1,3-dienes. Further, Co(I)-catalyst promotes cycloisomerization hydroalkenylation 1,6-enynes produce carbo- heterocyclic Surprisingly regioselectivity alkene depends whether it acrylate, acrylate produces uncommon Z-adduct. This Account will summary enabling basic discoveries attendant developments led unique Co(I)-complexes disparate C-B It hope stimulate work versatile derived from earth-abundant metal.

Язык: Английский

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Enantioselective C−H functionalization reactions enabled by cobalt catalysis

Chem Catalysis, Год журнала: 2022, Номер 2(11), С. 2965 - 2985

Опубликована: Сен. 16, 2022

Язык: Английский

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Nickel‐Catalyzed Defluorinative Asymmetric Cyclization of Fluoroalkyl‐Substituted 1,6‐Enynes for the Synthesis of Seletracetam

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(46)

Опубликована: Сен. 23, 2022

Abstract The introduction of fluorine‐containing groups into organic molecules can significantly affect their physical and chemical properties has long been used as an effective strategy for drug discovery development. Consequently, the development catalytic asymmetric methods synthesis heterocycles is highly desirable sought after. Herein, we describe a nickel‐catalyzed defluorinative cyclization fluoroalkyl‐substituted 1,6‐enynes, providing expedient access to synthetically attractive 4‐fluorovinyl‐substituted 2‐pyrrolidones in good yields with remarkable high levels chemo‐, regio‐, enantioselectivities (90–99 % ee,>35 examples). This protocol features readily available starting materials excellent functional group compatibility, exhibits complementary regioselectivity. utility this was demonstrated enantioselective antiepileptic Seletracetam.

Язык: Английский

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Cobalt-catalyzed enantioselective intramolecular reductive cyclization via electrochemistry

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

Опубликована: Март 9, 2023

Transition-metal catalyzed asymmetric cyclization of 1,6-enynes has emerged as a powerful method for the construction carbocycles and heterocycles. However, very rare examples worked under electrochemical conditions. We report herein Co-catalyzed enantioselective intramolecular reductive coupling enynes via electrochemistry using H2O hydride source. The products were obtained in good yields with high regio- enantioselectivities. It represents progress on cobalt-catalyzed transformation general substrate scope. DFT studies explored possible reaction pathways revealed that oxidative by LCo(I) is more favorable than addition or other pathways.

Язык: Английский

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Recent Advances in Cyclization Reactions of 1,6‐Enynes

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(6), С. 1220 - 1268

Опубликована: Янв. 22, 2024

Abstract Elaborated molecular architectures, specifically those bearing one or more carbon stereocenters, stand as an important class of carbocyclic and heterocyclic frameworks because they are frequently occurring core structures in numerous natural products biologically active pharmaceutical molecules. Over the past few decades, development versatile synthetic approaches via cascade cyclization reactions 1,6‐enynes for construction a series fused spiro compounds has been focus great deal research initiatives. These synthesis strategies peculiarly fascinating context assembly wide array molecules, products, agrochemicals, functional materials. In this review, recent developments transformations with diverse coupling reagents summarized since 2018, which could be divided into five categories: 1) Introduction; 2) Transition metal catalyzed 1,6‐enynes; 3) Metal‐free 4) Visible‐light‐induced 5) Electrocatalytic 1,6‐enynes.

Язык: Английский

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Nickel-catalyzed switchable arylative/endo-cyclization of 1,6-enynes

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Апрель 4, 2024

Abstract Carbo- and heterocycles are frequently used as crucial scaffolds in natural products, fine chemicals, biologically pharmaceutically active compounds. Transition-metal-catalyzed cyclization of 1,6-enynes has emerged a powerful strategy for constructing functionalized carbo- heterocycles. Despite significant progress, the regioselectivity alkyne functionalization is entirely substrate-dependent. And only exo -cyclization/cross-coupling products can be obtained, while endo -selective cyclization/cross-coupling remains elusive still poses formidable challenge. In this study, we disclose nickel-catalyzed switchable arylation/cyclization which nature ligand dictates arylation, electrophilic trapping reagents determine selectivity mode. Specifically, using commercially available 1,10-phenanthroline facilitates trans -arylation/cyclization to obtain seven-membered ring 2-naphthyl-substituted bisbox promotes cis access six-membered products. Diastereoselective cyclizations have also been developed synthesis enantioenriched piperidines azepanes, core structural elements pharmaceuticals possessing important biological activities. Furthermore, experimental density functional theory studies reveal that arylation process controlled by steric hindrance ligand; reaction mechanism involves -cyclization followed Dowd-Beckwith-type expansion form

Язык: Английский

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Diastereo- and Enantioselective Construction of Spirocycles by Nickel-Catalyzed Cascade Borrowing Hydrogen Cyclization

Journal of the American Chemical Society, Год журнала: 2020, Номер 143(1), С. 53 - 59

Опубликована: Дек. 24, 2020

Spirocycles play an important role in drug discovery and development owing to their inherent three-dimensionality structural novelty. Despite the recent significant progress, straightforward catalytic asymmetric assembly of spirocyclic scaffolds with multiple stereocenters from readily available starting materials remains a formidable challenge. Herein, we develop unprecedented nickel-catalyzed one-pot synthesis enantioenriched spiroindanones easily 1,6-enynes o-formylarylboronic acids. The reaction proceeds smoothly under redox-neutral conditions, without need for additional hydrogen donor, features broad substrate scope excellent regio-, enantio-, diastereoselectivity.

Язык: Английский

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α- and β-Functionalized Ketones from 1,3-Dienes and Aldehydes: Control of Regio- and Enantioselectivity in Hydroacylation of 1,3-Dienes

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(32), С. 12825 - 12835

Опубликована: Авг. 5, 2021

Ketones are among the most widely used intermediates in organic synthesis, and their synthesis from inexpensive feedstocks could be quite impactful. Regio- enantioselective hydroacylation reactions of dienes provide facile entry into useful ketone-bearing chiral motifs with an additional latent functionality (alkene) suitable for further elaboration. Three classes dienes, 2- or 4-monosubstituted 2,4-disubstituted 1,3-dienes, undergo cobalt(I)-catalyzed regio- hydroacylation, giving products high enantiomeric ratios (er). These highly dependent on ligands, we have identified ligands reaction conditions each class dienes. 2-Substituted predominantly 1,2-addition, whereas 4-substituted terminal give 4,1- 4,3-hydroacylation depending aldehyde, aliphatic aldehydes 4,1-addition aromatic 4,3-addition. Included substrates feedstock isoprene (US$1.4/kg) myrcene (US$129/kg), several common aldehydes. We propose oxidative dimerization mechanism that involves a Co(I)/Co(III) redox cycle appears to initiated by cationic Co(I) intermediate. Studies using isolated neutral complexes confirm critical role these reactions. Enantioselective 1,2-hydroacylation 2-trimethylsiloxy-1,3-diene reveals hitherto undisclosed route siloxy-protected aldols. Finally, syntheses anti-inflammatory drug (S)-Flobufen (2 steps, 92% yield, >99:1 er) food additive (S)-Dihydrotagetone (1 step, 83% yield; 96:4 illustrate power this method preparation commercially relevant compounds.

Язык: Английский

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