Decarboxylative tandem C-N coupling with nitroarenes via SH2 mechanism

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Май 4, 2022

Abstract Aromatic tertiary amines are one of the most important classes organic compounds in chemistry and drug discovery. It is difficult to efficiently construct from primary via classical nucleophilic substitution due consecutive overalkylation. In this paper, we have developed a radical tandem C-N coupling strategy aromatic commercially available carboxylic acids nitroarenes. A variety can be furnished good yields (up 98%) with excellent functional group compatibility under mild reaction conditions. The use two different also allows for concise synthesis nonsymmetric satisfactory yields. Mechanistic studies suggest intermediacy arylamine–(TPP)Fe(III) species might provide possible evidence an S H 2 (bimolecular homolytic substitution) pathway critical bond formation step.

Язык: Английский

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Carbene Radicals in Transition-Metal-Catalyzed Reactions

ACS Catalysis, Год журнала: 2023, Номер 13(8), С. 5428 - 5448

Опубликована: Апрель 6, 2023

Discovered as organometallic curiosities in the 1970s, carbene radicals have become a staple modern-day homogeneous catalysis. Carbene exhibit nucleophilic radical-type reactivity orthogonal to classical electrophilic diamagnetic Fischer carbenes. Their successful catalytic application has led synthesis of myriad carbo- and heterocycles, ranging from simple cyclopropanes more challenging eight-membered rings. The field matured employ densely functionalized chiral porphyrin-based platforms that high enantio-, regio-, stereoselectivity. Thus far focus largely been on cobalt-based systems, but interest growing for past few years expand other transition metals. This Perspective covers advances made since 2011 gives an overview coordination chemistry, reactivity, radical species using metal complexes catalysts.

Язык: Английский

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Visible-Light-Mediated Energy Transfer Enables Cyclopropanes Bearing Contiguous All-Carbon Quaternary Centers

ACS Catalysis, Год журнала: 2023, Номер 13(14), С. 9806 - 9816

Опубликована: Июль 11, 2023

Cyclopropanes bearing contiguous all-carbon quaternary centers continue to attract attention due their bioactivities. However, methods obtain cyclopropanes with remain largely unexplored the high steric hindrance of these compounds. Herein, we report a visible-light-mediated energy-transfer (EnT) strategy realize in situ donor/donor carbenes from readily available N-tosylhydrazones, facilitating synthesis highly congested EWG-free cyclopropanes. Through this approach, are rapidly installed into complex bioactive molecules, fluorescent and other useful building blocks that challenging synthesize. Detailed mechanistic reactions DFT studies clearly demonstrated role photosensitizer, formation carbenes, necessity light base system.

Язык: Английский

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Biomimetic asymmetric catalysis

Science China Chemistry, Год журнала: 2023, Номер 66(6), С. 1553 - 1633

Опубликована: Апрель 25, 2023

Язык: Английский

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Asymmetric Radical Bicyclization for Stereoselective Construction of Tricyclic Chromanones and Chromanes with Fused Cyclopropanes

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(21), С. 11622 - 11632

Опубликована: Май 2, 2023

Asymmetric radical bicyclization processes have been developed via metalloradical catalysis (MRC) to stereoselectively construct chiral chromanones and chromanes bearing fused cyclopropanes. Through optimization of a versatile

Язык: Английский

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Vitamin B₁₂‐Photocatalyzed Cyclopropanation of Electron‐Deficient Alkenes Using Dichloromethane as the Methylene Source**

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(2)

Опубликована: Ноя. 28, 2023

Abstract The cyclopropyl group is of great importance in medicinal chemistry, as it can be leveraged to influence a range pharmaceutical properties drug molecules. This report describes Vitamin B 12 ‐photocatalyzed approach for the cyclopropanation electron‐deficient alkenes using dichloromethane (CH 2 Cl ) methylene source. reaction proceeds good excellent yields under mild conditions, has functional compatibility, and highly chemoselective. scope could also extended preparation D ‐cyclopropyl methyl‐substituted adducts starting from CD 1,1‐dichloroethane, respectively.

Язык: Английский

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From Serendipity to Rational Design: Heteroleptic Dirhodium Amidate Complexes for Diastereodivergent Asymmetric Cyclopropanation

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(16), С. 7465 - 7478

Опубликована: Апрель 14, 2022

A heteroleptic dirhodium paddlewheel complex comprising three chiral carboxylate ligands and one achiral acetamidate ligand has recently been found to be uniquely effective in catalyzing the asymmetric cyclopropanation of olefins with α-stannylated (silylated germylated) α-diazoacetate derivatives. number control experiments combination detailed computational studies provide compelling evidence that an interligand hydrogen bond between −NH group amidate ester carbonyl reactive rhodium carbene intermediate plays a quintessential role stereodetermining transition state. The penalty for distorting this array outweighs steric arguments renders two four conceivable transitions states unviable. Based on mechanistic insight, design parent catalyst is revisited herein: placement appropriate peripheral substituents allows high levels diastereocontrol imposed upon cyclopropanation, which original lacks. Because new complexes allow either trans- or cis-configured stannylated cyclopropanes made selectively excellent optical purity, transformation also marks rare case diastereodivergent catalysis. products are amenable stereospecific cross coupling aryl halides alkenyl triflates; these transformations appear first examples formation stereogenic quaternary carbon centers by Stille reaction; carbonylative achieved. Moreover, tin/lithium exchange affords lithium enolates, can intercepted variety electrophilic partners. virtues inherent flexibility methodology illustrated efficient synthesis salinilactones, extremely scarce bacterial metabolites signaling function involved self-regulatory growth inhibition producing strain.

Язык: Английский

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Who is Who in the Carbene Chemistry of N‐Sulfonyl Hydrazones

Chinese Journal of Chemistry, Год журнала: 2024, Номер 42(17), С. 2071 - 2108

Опубликована: Май 27, 2024

Comprehensive Summary Over the past few decades, N ‐sulfonyl hydrazones have been recognized as alternative precursors for hazardous diazo compounds in organic synthesis, allowing diverse innovative and original chemical transformations that were otherwise difficult to achieve. This critical review summarizes major advancements carbene chemistry of hydrazones. The contents this are organized based on research conducted by leading scientists who made significant contributions field. individual transfer reactions their mechanisms, well potential applications synthesis natural products complex bioactive molecules, thoroughly discussed.

Язык: Английский

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UV Light Is No Longer Required for the Photoactivation of 1,3,4-Oxadiazolines

ACS Catalysis, Год журнала: 2023, Номер 13(3), С. 1964 - 1973

Опубликована: Янв. 20, 2023

Carbenes play a key role in plethora of organic transformations. Although stabilized diazo carbonyl compounds predominate as source electrophilic carbenes, the hazardous nature nonstabilized analogues calls for their situ generation from stable precursors. Among these, 1,3,4-oxadiazolines serve diazoalkane surrogates under UV light irradiation. In view high stability, diverse reactivities, and straightforward synthesis, milder methodologies activation these that permit use UV-light-sensitive substrates are highly valued. Herein, we report visible-light-induced oxadiazolines by triplet energy transfer catalysis that, contrast to UV-induced processes, alters reactivity enables carbenes. The formed reactive species react with electron-poor olefins, thereby giving valuable spirocyclopropanes. Mechanistic investigations, both theoretical experimental, uncover plausible pathways highlight importance steps.

Язык: Английский

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Catalytic Olefin Cyclopropanation with In Situ-Generated Dialkyl Diazomethanes via Co(II)-Based Metalloradical Catalysis

ACS Catalysis, Год журнала: 2023, Номер 13(17), С. 11851 - 11856

Опубликована: Авг. 23, 2023

The synthesis of dialkyl-substituted cyclopropanes is an important challenge in with applications drug discovery and agrochemistry. Herein, we report on the gem-dialkyl situ-generated dialkyl diazo compounds under Bamford–Stevens conditions. A simple cobalt catalyst was identified to be optimal achieve high yields. Experimental computational studies suggest participation a metalloradical reaction mechanism that facilitates carbene transfer reactions provides access single step.

Язык: Английский

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