Enantioselective Total Syntheses of Vallesamidine and Schizozygane Alkaloids

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Янв. 27, 2025

A general streamlined strategy for the enantioselective total syntheses of schizozygane family natural products and related alkaloid vallesamidine is described. Specifically, a catalytic enantioconvergent cross-coupling sets quaternary stereogenic center in pluripotent intermediate adorned with an olefin three orthogonal carboxylate groups, upon which modularity synthesis relies. late-stage oxidative lactamization alkyne instrumental first-generation alkaloids. In second-generation approach, novel application van Leusen reaction generation lactams pivotal to accessing alkaloids from common intermediate. The strategies outlined here are expected enable detailed biological investigations as well facilitate access provide solutions modification bioactive

Язык: Английский

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A General Enantioselective α-Alkyl Amino Acid Derivatives Synthesis Enabled by Cobalt-Catalyzed Reductive Addition

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Сен. 12, 2024

Enantioenriched unnatural amino acids represent a prevalent motif in organic chemistry, with profound applications biochemistry, medicinal and materials science. Herein, we report cobalt-catalyzed aza-Barbier reaction of dehydroglycines unactivated alkyl halides to afford α-amino esters high enantioselectivity. This catalytic reductive alkylative addition protocol circumvents the use moisture-, air-sensitive organometallic reagents, stoichiometric chiral auxiliaries, enabling conversion variety primary, secondary, even tertiary α-alkyl-amino under mild conditions, thus leading broad functional group tolerance. The expedient access biologically active motifs demonstrates practicality this by reducing number synthetic steps enhancing efficiency.

Язык: Английский

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Paired Electro‐Synthesis of Remote Amino Alcohols with/in H2O

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 13, 2024

Abstract Amino alcohols, particularly remote amino alcohols and peptide are valuable due to their functional diversity in biologically active compounds. However, traditional synthesis methods face significant challenges, making electrochemistry an attractive alternative. We have developed a mild biocompatible sequential paired electrolysis strategy, leveraging copper‐electrocatalysis synthesize diverse including unnatural alcohols. Both experimental results density theory (DFT) calculations demonstrated that water serves as both the hydroxyl source solvent, facilitating generation of CuH with Cu(I) at cathode, which turn reduces aldehyde intermediates formed during reaction.

Язык: Английский

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Electrochemical Synthesis of Itaconic Acid Derivatives via Chemodivergent Single and Double Carboxylation of Allenes with CO₂

Chemistry - A European Journal, Год журнала: 2024, Номер 30(49)

Опубликована: Июнь 24, 2024

Abstract Leveraging electrochemistry, a new synthesis of non‐natural derivatives itaconic acid is proposed by utilizing carbon dioxide (CO 2 ) as valuable C1 synthon. An electrochemical cross‐electrophile coupling between allenoates and CO was targeted, allowing for the both mono‐ di‐carboxylation products in catalyst‐ additive‐free environment (yields up to 87 %, 30 examples). Elaboration model mono‐carboxylation product, detailed cyclovoltammetric, well mechanistic analyses complete present investigation.

Язык: Английский

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Catalytic Asymmetric Barbier Reaction of Ketones with Unactivated Alkyl Electrophiles

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Окт. 3, 2024

The Barbier reaction is a reductive-type addition of an aldehyde or ketone with organic electrophile in the presence terminal metal reductant, providing straightforward and efficient method for carbon-carbon bond formation. This possesses advantage circumventing preparation moisture- air-sensitive organometallic reagents. However, catalytic ketones to construct tetrasubstituted stereogenic centers largely underdeveloped, despite its great potential accessing synthetically challenging chiral tertiary alcohol. Particularly, leveraging unactivated alkyl electrophiles as coupling components still rarely exploited. Herein, we disclose photoredox-assisted cobalt-catalyzed asymmetric alkylative Barbier-type address aforementioned challenges, thereby allowing construction highly congested carbon centers. fragments could be either readily accessible halides redox-active esters generated through decarboxylative pathway. Both types include primary, secondary, ones, thus affording diverse enantioenriched alcohols broad substrate scope. enantioselective protocol applied expedient synthesis core structure

Язык: Английский

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Electrochemical Approach Toward Mesoionic 1,2,3‐Triazole 1‐Imines

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер unknown

Опубликована: Авг. 22, 2024

Abstract Synthetic electrochemistry may establish direct routes to a preparation of plethora organic substances, which are hardly accessible by conventional experimental techniques. Herein, we present an electrochemically‐driven method for assembly broad range rare heterocyclic mesoionic entities –1,2,3‐triazole 1‐imines. These nitrogen heterocycles were prepared through transition‐metal‐ and exogenous oxidant‐free strategy using C/Ni electrode pair. Over 30 examples thus synthesized 1,2,3‐triazole 1‐imines illustrate selectivity practical utility this approach. Key solvent‐controlled reactivity patterns the formation triazole imine scaffold revealed indicating modulation ability developed findings additionally justified based on cyclic voltammetry (CV) data density functional theory (DFT) calculations. Moreover, according differential scanning calorimetry (DSC) data, some correspond thermally stable species with onset decomposition temperature up 190 °C.

Язык: Английский

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Synthesis of Some New Chiral Triazole-oxazoline Derivatives

Current Organic Synthesis, Год журнала: 2024, Номер 22(1), С. 136 - 142

Опубликована: Июль 12, 2024

: Some new (S)-2-[1-aryl-5-methyl-1H-1,2,3-triazol-4-yl]-4-benzyl-4,5-dihydro-ox-azoline were synthesized by the reaction of (S)-N-(1-hydroxy-3-phenylpropan-2-yl)-1-aryl-5-methyl-1H-1,2,3-triazole-4-carboxamides which prepared from aromatic amine as start-ing materials, with p-toluenesulfonyl chloride, triethylamine and DMAP. The structures characterized 1H NMR, 13C MS IR. chiral triazole-oxazoline was used a ligand in Diels-Alder asymmetric catalytic between 3-allyl-1,3-ox-azolidin-2-ketone 2-methyl-1,3-butadiene, using PdCl2 catalyst. (S)-3-(4-methylcyclo-hexe-3-ene-1-formyl)-1,3-oxazolidin-2-one obtained. Background: ligands are rarely reported. Objective: aim study to synthsize some (S)-4-benzyl-2-(1-aryl-5-methyl-1H-1,2,3-triazole-4-yl)-4,5-dihydrooxazoline (5a-g). Methods: one-pot methods oriented synthesis adopted. This provides sim-ple effective method for derivatives. Results: (5a-g) cyclization 3-allyl-1,3-oxazolidin-2-ketone 2-methyl-1,3-butadiene catalyzed (S)-4-triazole-oxazoline ligands. Conclusion: (S)-4-benzyl-2-(1-aryl-5-methyl-1H-1,2,3-triazole-4-yl)-4,5-dihydro-oxazoline corresponding N-[(S)-1-hydroxy-3-phenylpropan-2-yl]-1-aryl-5-methyl-1H-1,2,3-triazole-4-formamide, through method. After preliminary evaluation, triazoline-oxazoline ligands, 1,2,3-triazole rings, like pyridine-type materials saved replace one oxazoline ring di-oxazoline reactions.

Язык: Английский

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Alkene Cyclopropanation with gem-Dichloroalkanes Catalyzed by (PNN)Co Complexes: Scope and Mechanism

ACS Catalysis, Год журнала: 2024, Номер 14(17), С. 12846 - 12856

Опубликована: Авг. 12, 2024

Highly regioselective and diastereoselective cis-arylcyclopropanation (ACP) trans-vinylcyclopropanation (VCP) of 1-alkenes with gem-dichloroalkanes are described. By employing stable readily available donor carbene precursors zinc powder as the additive, cobalt dichloride complex (tBuPNN)CoCl2 a phosphinobipyridine (PNN) pincer tBu substituents on phosphorus atom catalyzes mild efficient cyclopropanation high functional-group compatibility wide substrate scope, furnishing diastereoselectivity in case trans-VCP that remains underdeveloped. The synthetic potential was demonstrated by late-stage modification bioactive molecules. Stoichiometric experiments cyclic voltammetry provide insights into reaction mechanism identify key factors to achieve this reaction; particular importance is relatively slow reduction gem-dichloroalkane formal CoI species (tBuPNN)CoCl keep free alkyl radical at low concentration, elucidated relationship between catalytic activity potentials four (tBuPNN)Co complexes various electronic properties.

Язык: Английский

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Electrochemical Decarboxylation Coupling Reactions

Chemistry - A European Journal, Год журнала: 2024, Номер 30(66)

Опубликована: Окт. 16, 2024

Abstract Carboxylic acids are attractive synthetic feedstocks with stable, non‐toxic, and inexpensive properties that can be easily obtained from natural sources or through synthesis. have long been considered environmentally friendly coupling agents in various organic transformations. In recent years, electrochemically mediated decarboxylation reactions of decarboxylic their derivatives (NHPI) emerged as effective new methods for constructing carbon‐carbon carbon‐heterocarbon chemical bonds. Compared transition metal photochemistry‐mediated catalytic reactions, which do not require the addition oxidants strong bases, electrochemically‐mediated decarboxylative transformations a sustainable strategy. addition, functional groups tolerate electrochemical conversion strategy well. Here, we summarize to better elucidate advantages reactions.

Язык: Английский

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Paired Electro‐Synthesis of Remote Amino Alcohols with/in H2O

Angewandte Chemie, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 13, 2024

Abstract Amino alcohols, particularly remote amino alcohols and peptide are valuable due to their functional diversity in biologically active compounds. However, traditional synthesis methods face significant challenges, making electrochemistry an attractive alternative. We have developed a mild biocompatible sequential paired electrolysis strategy, leveraging copper‐electrocatalysis synthesize diverse including unnatural alcohols. Both experimental results density theory (DFT) calculations demonstrated that water serves as both the hydroxyl source solvent, facilitating generation of CuH with Cu(I) at cathode, which turn reduces aldehyde intermediates formed during reaction.

Язык: Английский

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