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 and Heterogeneous Gold Catalysis for Materials Science

Chemical Reviews, Journal Year: 2020, Volume and Issue: 121(14), P. 9113 - 9163

Published: Dec. 14, 2020

Often stoichiometric amounts of gold find use in materials science; occasionally is even used as a support. This review discusses the contributions catalysis, both homogeneous and heterogeneous, to field science. One topic synthesis polymers, including nanowires polyesters, postcyclization polymerization by cyclopropanation, gold-catalyzed radical reactions. Other topics are dyes, phosphonium salts, wide range extended conjugated π-systems, latter ranging from acenes, pentalene derivatives, different heterocyclic π-systems fascinating applications helical anellated aromatic molecules. The existing clearly demonstrate potential catalysis for significant future impulses

Language: Английский

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Sulfilimines as Versatile Nitrene Transfer Reagents: Facile Access to Diverse Aza‐Heterocycles

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(11), P. 3589 - 3593

Published: Jan. 2, 2019

Abstract We herein report the unprecedented synthesis of diverse biologically important aza‐heterocycles by employing sulfilimines as nitrene transfer reagents. This class sulfur‐based aza‐ylides had not been successfully used for gold before. work contains an efficient generation α‐imino carbenes N−S cleavage sulfilimines. These undergo C−H insertion, cyclopropanation, and nucleophilic attack to form indoles (44 examples), 3‐azabicyclo[3.1.0]hexan‐2‐imines (24 imidazoles (3 examples). Our study represents a unique gold‐catalyzed reaction between alkynes sulfur ylides, also includes first aza‐heterocycle that proceeds intermolecular followed cyclopropanation carbenes. Moreover, unexpected 4‐acylquinolines examples) from 2‐acylphenyl propargylic silyl ether derivatives 1,2‐hydride shift onto carbene subsequent Mukaiyama aldol cyclization was discovered.

Language: Английский

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Silver-catalyzed decarboxylative radical cascade cyclization toward benzimidazo[2,1-a]isoquinolin-6(5H)-ones

Chemical Communications, Journal Year: 2019, Volume and Issue: 55(19), P. 2861 - 2864

Published: Jan. 1, 2019

A simple and efficient decarboxylative radical addition/cyclization strategy was developed, by which a wide range of benzimidazo[2,1-a]isoquinoline-6(5H)-ones were prepared in one-pot via reaction functionalized 2-arylbenzoimidazoles carboxylic acids the presence K2S2O8/AgNO3 under mild conditions.

Language: Английский

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Acyl Migration versus Epoxidation in Gold Catalysis: Facile, Switchable, and Atom‐Economic Synthesis of Acylindoles and Quinoline Derivatives

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(1), P. 471 - 478

Published: Oct. 17, 2019

Abstract We report a switchable synthesis of acylindoles and quinoline derivatives via gold‐catalyzed annulations anthranils ynamides. α‐Imino gold carbenes, generated in situ from an N,O‐coordinated gold(III) catalyst, undergo electrophilic attack to the aryl π‐bond, followed by unexpected highly selective 1,4‐ or 1,3‐acyl migrations form 6‐acylindoles 5‐acylindoles. With (2‐biphenyl)di‐ tert ‐butylphosphine (JohnPhos) ligand, gold(I) carbenes experienced carbene/carbonyl additions deliver oxides. Some these epoxides are valuable substrates for preparation 3‐hydroxylquinolines, quinolin‐3(4 H )‐ones, polycyclic compounds facile rearrangements. The reaction can be efficiently conducted on gram scale obtained products preparing other potentially useful compounds. A computational study explained selectivities dependency pathway oxidation state ligands gold. barrier formation strained oxirane ring is too high; whereas with this transition becomes accessible. Furthermore, energetic barriers migration substituents intermediate sigma‐complexes support observed substitution pattern final product.

Language: Английский

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

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(50), P. 16549 - 16553

Published: Oct. 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.

Language: Английский

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

Organic Chemistry Frontiers, Journal Year: 2019, Volume and Issue: 6(9), P. 1513 - 1540

Published: Jan. 1, 2019

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

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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Recent Advances in C–H Activation for the Synthesis of π-Extended Materials

ACS Materials Letters, Journal Year: 2020, Volume and Issue: 2(8), P. 951 - 974

Published: June 29, 2020

The activation of typically unreactive aromatic C–H bonds by transition-metal catalysis has been receiving increased attention from the synthetic chemistry community in recent years. Advances this area have enabled direct and site-selective modification rings without need for pre-functionalization. Accordingly, these techniques found broad application many fields, including construction extended π-systems use materials science. This review will discuss reports reactions applied toward synthesis π-extended functional materials.

Language: Английский

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Pd‐Catalyzed Dearomatization of Anthranils with Vinylcyclopropanes by [4+3] Cyclization Reaction

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(17), P. 5739 - 5743

Published: Feb. 27, 2019

Abstract Dearomatization of anthranils with vinylcyclopropanes (VCPs) by Pd‐catalyzed [4+3] cyclization reaction has been realized. In the presence a catalytic amount borane as an activator, bridged cyclic products were obtained in good to excellent yields stereoselectivities. By introducing chiral PHOX ligand ( L5 ), asymmetric dearomatization reactions proceeded enantioselectivity. Borane plays key role for reactivity, likely owing formation borane–anthranil complex which confirmed NMR experiments.

Language: Английский

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