Transition Metal-Catalyzed Tandem Reactions of Ynamides for Divergent N-Heterocycle Synthesis

Accounts of Chemical Research, Год журнала: 2020, Номер 53(9), С. 2003 - 2019

Опубликована: Сен. 1, 2020

ConspectusYnamides are electron-rich heteroatom-substituted alkynes with a C-C triple bond directly attached to the amide group. Importantly, this group is able impose an electronic bias, thus resulting in highly regioselective attack of polarized alkyne by large variety nucleophiles. Over past two decades, catalytic reactions ynamides have experienced dramatic developments, especially those catalyzed transition metals. As result, been widely applied rapid and efficient assembly versatile structurally complex N-containing molecules, atom-economic stereoselective way.On basis newly developed ynamide preparations new transformations, we first oxidation-initiated tandem such as zinc-catalyzed oxidation/C-H functionalization copper-catalyzed oxidation/carbene metathesis, leading divergent synthesis isoquinolones, β-carbolines, pyrrolo[3,4-c]quinolin-1-ones. protocol represents non-noble-metal-catalyzed intermolecular oxidation N-oxide type oxidants, related overoxidation could be dramatically inhibited non-noble-metal catalysis. Then, achieved gold-catalyzed amination-initiated via α-imino gold carbenes for construction various 2-aminoindoles, 3-amino-β-carbolines, 2-aminopyrroles, where types nitrene transfer reagents (benzyl azides isoxazoles) were discovered. In particular, use isoxazoles generation metal has also elegantly exploited Hashmi, Liu, many other groups, providing ready access wide range functionalized N-heterocycles. Moreover, revealed that donor/donor copper generated diyne cyclization under mild conditions. These novel undergo asymmetric C-H insertion, cyclopropanation, formal [3 + 2] cycloaddition produce diverse chiral polycyclic pyrroles good excellent enantioselectivities. Thus, strategy may open avenues reaction ynamides, which remain largely unexplored deserve more attention. Meanwhile, accomplished practical medium-sized lactams yttrium-catalyzed cascade allyl alcohol-tethered combination radical chemistry based on visible-light photoredox catalysis useful 2-benzhydrylindoles 3-benzhydrylisoquinolines.In Account, describe panoramic picture our recent contributions since 2015 development application organic metal-catalyzed focusing tetrafunctionalization ynamides. studies provide not only attractive methods valuable N-heterocycles but some insights into exploration carbene chemistry.

Язык: Английский

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Nitrene Transfer and Carbene Transfer in Gold Catalysis

Chemical Reviews, Год журнала: 2020, Номер 121(14), С. 9039 - 9112

Опубликована: Авг. 3, 2020

Catalytic transformations involving metal carbenes are considered one of the most important aspects homogeneous transition catalysis. Recently, gold-catalyzed generation gold from readily available alkynes represents a significant advance in carbene chemistry. This Review summarizes advances nitrene-transfer reactions with nitrogen-transfer reagents, such as azides, nitrogen ylides, isoxazoles, and anthranils, carbene-transfer reactions, oxygen atom-transfer nitro compounds, nitrones, sulfoxides, pyridine N-oxides, through presumable α-imino α-oxo intermediates, respectively. Gold-catalyzed processes reviewed by highlighting their product diversity, selectivity, applicability, mechanistic rationale is presented where possible.

Язык: Английский

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Reversal of Regioselectivity in Ynamide Chemistry

ACS Catalysis, Год журнала: 2019, Номер 9(7), С. 6393 - 6406

Опубликована: Июнь 5, 2019

Ynamides are special alkynes bearing an electron-withdrawing group on the nitrogen atom, and they have been extensively studied over past decade. However, addition of functional groups across ynamides in these transformations typically occurs at α-position ynamide because strong polarization alkynyl moiety. Studies umpolung chemistry may not only discover organic reactions but also lead to divergent syntheses, thus significantly enriching chemistry. This review summarizes four main strategies utilized achieve reversal regioselectivity, including ring strain factor, metal–carbonyl (or sulfonyl) chelation, base-mediated radical-initiated addition.

Язык: Английский

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Brønsted acid-mediated reactions of ynamides

Chemical Society Reviews, Год журнала: 2020, Номер 49(24), С. 8897 - 8909

Опубликована: Янв. 1, 2020

This review summarizes the latest trends and developments of Brønsted acid-mediated reactions ynamides, including cycloaddition, cyclization so on.

Язык: Английский

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Gold-Catalyzed Synthesis of Small Rings

Chemical Reviews, Год журнала: 2020, Номер 121(14), С. 8613 - 8684

Опубликована: Ноя. 2, 2020

Three- and four-membered rings, widespread motifs in nature medicinal chemistry, have fascinated chemists ever since their discovery. However, due to energetic considerations, small rings are often difficult assemble. In this regard, homogeneous gold catalysis has emerged as a powerful tool construct these highly strained carbocycles. This review aims provide comprehensive summary of all the major advances discoveries made gold-catalyzed synthesis cyclopropanes, cyclopropenes, cyclobutanes, cyclobutenes, corresponding heterocyclic or heterosubstituted analogs.

Язык: Английский

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1,2-Migrations onto Gold Carbene Centers

Chemical Reviews, Год журнала: 2020, Номер 121(14), С. 8948 - 8978

Опубликована: Окт. 7, 2020

Gold carbenes are highly active intermediates in homogeneous gold catalysis, enabling a large array of transformations such as C–H/X–H insertions, cyclopropanations, and 1,2-migrations. Unlike insertions 1,2-migrations onto carbene centers seem to be attracting less attention. There has been no comprehensive review focusing on this topic, even though chemistry become powerful tool for the rapid simple construction molecular complexity. This provides critical information centers, drawing preliminary conclusion migratory aptitude various groups. The is divided into several parts according kind precursors.

Язык: Английский

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Gold‐Catalyzed Regiospecific C−H Annulation of o‐Ethynylbiaryls with Anthranils: π‐Extension by Ring‐Expansion En Route to N‐Doped PAHs

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(23), С. 6935 - 6939

Опубликована: Апрель 10, 2018

Abstract We describe a novel, short, and flexible approach to diverse N‐doped polycyclic aromatic hydrocarbons (PAHs) through gold‐catalyzed π‐extension of anthranils with o ‐ethynylbiaryls as reagents. This strategy uses easily accessible starting materials, is simple due high step atom economy, shows good functional‐group compatibility well scale‐up potential. Mechanistically, the tandem reaction proposed involve nucleophilic addition/ring opening/regiospecific C−H annulation/protodeauration sequence terminated by Friedel–Crafts‐type cyclization. Photophysical studies products indicated violet‐blue fluorescence emission quantum yields up 0.45.

Язык: Английский

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Gold(III)‐Catalyzed Site‐Selective and Divergent Synthesis of 2‐Aminopyrroles and Quinoline‐Based Polyazaheterocycles

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(50), С. 16549 - 16553

Опубликована: Окт. 11, 2018

Abstract A facile, site‐selective, and divergent approach to construct 2‐aminopyrroles quinoline‐fused polyazaheterocycles enabled by a simple gold(III) catalyst from ynamides anthranils under mild reaction conditions is described. This one‐pot strategy uses readily available starting materials, proceeds in highly step‐ atom‐economical manner, with broad substrate scope scale‐up potential. The key element for success this tandem catalyst‐directed preferred quenching of the situ generated gold carbene intermediates nucleophilic benzyl/2‐furylmethyl moiety on as an alternative known C−H annulation leading indoles.

Язык: Английский

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Gold-catalyzed heterocyclic syntheses through α-imino gold carbene complexes as intermediates

Organic Chemistry Frontiers, Год журнала: 2019, Номер 6(9), С. 1513 - 1540

Опубликована: Янв. 1, 2019

This review reports a comprehensive compilation of gold-catalyzed heterocyclic synthesis by using α-imino gold carbene complexes as the proposed intermediates.

Язык: Английский

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α‐Imino Gold Carbene Intermediates from Readily Accessible Sulfilimines: Intermolecular Access to Structural Diversity

Chemistry - A European Journal, Год журнала: 2019, Номер 26(15), С. 3197 - 3204

Опубликована: Дек. 3, 2019

Abstract Catalytic approaches to pharmaceutically important bioactive skeletons through gold carbene intermediates have experienced a dramatic development in the last decade. Although various precursors continue play an role heterocyclic syntheses, these reagents are associated with some drawbacks terms of functional group tolerance, synthetic methods and safety limitations. A new generation nitrene transfer was established 2019: sulfilimines. These safe, inexpensive readily available. They can conveniently be stored handled, thus represent ideal for fast modular modification scaffolds preparation libraries by intermolecular reactions two components. Both practical synthesizing sulfilimines versatility ylidic species gold‐catalyzed structural diversity, both heterocycles carbocycles, will outlined this Concept article.

Язык: Английский

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