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

Accounts of Chemical Research, Journal Year: 2020, Volume and Issue: 53(9), P. 2003 - 2019

Published: Sept. 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.

Language: Английский

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Nitrene Transfer and Carbene Transfer in Gold Catalysis

Chemical Reviews, Journal Year: 2020, Volume and Issue: 121(14), P. 9039 - 9112

Published: Aug. 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.

Language: Английский

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Homogeneous Gold-Catalyzed Oxidation Reactions

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(14), P. 8979 - 9038

Published: Feb. 16, 2021

Homogeneous gold catalysis has experienced extraordinary development since the dawn of this millennium. Oxidative is a vibrant and fertile subfield over years delivered diverse array versatile synthetic methods exceptional value to practices. This review aims cover topic in comprehensive manner. The discussions are organized by mechanistic aspects metal oxidation states further types oxidants or oxidizing functional groups. Synthetic applications oxidative also discussed.

Language: Английский

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Brønsted acid-mediated reactions of ynamides

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 49(24), P. 8897 - 8909

Published: Jan. 1, 2020

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

Language: Английский

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Gold-Catalyzed Synthesis of Small Rings

Chemical Reviews, Journal Year: 2020, Volume and Issue: 121(14), P. 8613 - 8684

Published: Nov. 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.

Language: Английский

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

Chemistry - A European Journal, Journal Year: 2019, Volume and Issue: 26(15), P. 3197 - 3204

Published: Dec. 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.

Language: Английский

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Generation of Donor/Donor Copper Carbenes through Copper-Catalyzed Diyne Cyclization: Enantioselective and Divergent Synthesis of Chiral Polycyclic Pyrroles

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(42), P. 16961 - 16970

Published: Sept. 26, 2019

The generation of metal carbenes from readily available alkynes represents a significant advance in carbene chemistry. However, most these transformations are based on the use noble-metal catalysts and successful examples such an asymmetric version still very scarce. Here copper-catalyzed enantioselective cascade cyclization N-propargyl ynamides is reported, enabling practical atom-economical construction diverse chiral polycyclic pyrroles generally good to excellent yields with wide substrate scope enantioselectivities (up 97:3 e.r.). Importantly, this protocol first diyne cyclization. Moreover, mechanistic studies revealed that donor/donor copper presumably involved 1,5-diyne cyclization, which distinctively different related gold catalysis, thus it constitutes novel way for carbenes.

Language: Английский

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Copper‐Catalyzed Azide–Ynamide Cyclization to Generate α‐Imino Copper Carbenes: Divergent and Enantioselective Access to Polycyclic N‐Heterocycles

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(41), P. 17984 - 17990

Published: July 4, 2020

Here an efficient copper-catalyzed cascade cyclization of azide-ynamides via α-imino copper carbene intermediates is reported, representing the first generation carbenes from alkynes. This protocol enables practical and divergent synthesis array polycyclic N-heterocycles in generally good to excellent yields with broad substrate scope diastereoselectivities. Moreover, asymmetric azide-ynamide has been achieved high enantioselectivities (up 98:2 e.r.) by employing BOX-Cu complexes as chiral catalysts. Thus, this constitutes example azide-alkyne cyclization. The proposed mechanistic rationale for further supported theoretical calculations.

Language: Английский

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Copper‐Catalyzed Enantioselective Doyle–Kirmse Reaction of Azide‐Ynamides via α‐Imino Copper Carbenes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(10)

Published: Jan. 14, 2023

[2,3]-Sigmatropic rearrangement reaction involving sulfonium ylide (Doyle-Kirmse reaction) generated from metal carbenes represents one of the powerful methods for construction C(sp3 )-S and C-C bonds. Although significant advances have been achieved, asymmetric versions via generation ylides rarely reported to date, they so far limited diazo compounds as carbene precursors. Here, we describe a copper-catalyzed enantioselective Doyle-Kirmse azide-ynamide cyclization, leading practical divergent assembly an array chiral [1,4]thiazino[3,2-b]indoles bearing quaternary carbon stereocenter in generally moderate excellent yields enantioselectivities. Importantly, this protocol unique catalytic non-diazo approach unprecedented [2,3]-sigmatropic α-imino carbenes.

Language: Английский

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Nature of the Nucleophilic Oxygenation Reagent Is Key to Acid-Free Gold-Catalyzed Conversion of Terminal and Internal Alkynes to 1,2-Dicarbonyls

The Journal of Organic Chemistry, Journal Year: 2019, Volume and Issue: 85(2), P. 745 - 757

Published: Dec. 18, 2019

2,3-Dichloropyridine N-oxide, a novel oxygen transfer reagent, allows the conductance of gold(I)-catalyzed oxidation alkynes to 1,2-dicarbonyls in absence any acid additives and under mild conditions furnish target species, including those derivatized by highly acid-sensitive groups. The developed strategy is effective for wide range alkyne substrates such as terminal- internal alkynes, ynamides, alkynyl ethers/thioethers, even unsubstituted acetylene (40 examples; yields up 99%). was successfully integrated into trapping reactive dicarbonyls one-pot heterocyclization synthesis six-membered azaheterocycles. This synthetic acid-free route also applied total natural 1,2-diketone.

Language: Английский

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