Organocatalytic Reactions Enabled by N-Heterocyclic Carbenes.

Beijing National Laboratory of Molecular Sciences (BNLMS) and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Green Chemistry Center, Peking University, 202 Chengfu Road, 098#, Beijing 100871, China State Key Laboratory of Organometallic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 200060, China

Transition-Metal-Free Coupling Reactions

This tutorial review is aimed at highlighting recent developments in transition-metal-free carbon–carbon and carbon–heteroatom bond-forming reactions utilizing a versatile class of reactive intermediates, viz., arynes, which hold the potential for numerous applications in organic synthesis. Key to the success of the resurgence of interest in the rich chemistry of arynes is primarily the mild condition for their generation by the fluoride-induced 1,2-elimination of 2-(trimethylsilyl)aryl triflates. Consequently, arynes have been employed for the construction of multisubstituted arenes with structural diversity and complexity. The versatile transition-metal-free applications of arynes include cycloaddition reactions, insertion reactions and multicomponent reactions. In addition, arynes have found applications in natural product synthesis. Herein, we present a concise account of the major developments that occurred in this field during the past eight years.

Recent advances in transition-metal-free carbon–carbon and carbon–heteroatom bond-forming reactions using arynes

About two decades after Kobayashi's discovery in 1983 of a very mild way of generating highly reactive aryne intermediates, the synthetic community embraced o-(trimethylsilyl)aryl triflates as convenient and versatile aryne precursors for the synthesis of carbocycles and heterocycles, as well as natural products and pharmaceutically promising drug candidates. This review provides a comprehensive overview of the construction of heterocycles using Kobayashi's silylaryl triflate aryne precursors. It is organized according to the type of heterocycle generated.

Use of benzynes for the synthesis of heterocycles

ConspectusArynes are highly reactive intermediates having several applications in organic synthesis for the construction of various ortho-disubstituted arenes. Traditionally, arynes are generated in solution from haloarenes under strongly basic conditions. However, the scopes of many of the aryne reactions are limited because of the harsh conditions used for their generation. The renaissance of interest in aryne chemistry is mainly due to the mild conditions for their generation by the fluoride-induced 1,2-elimination of 2-(trimethylsilyl)aryl triflates. This Account is focused on the Diels–Alder reaction of arynes and their transition-metal-free application in multicomponent couplings as well as arylation reactions.The Diels–Alder reaction of arynes is a powerful tool for constructing benzo-fused carbocycles and heterocycles. In 2012, we developed an efficient, broad-scope, and scalable Diels–Alder reaction of pentafulvenes with arynes affording benzonorbornadiene derivatives. Subsequently, we accomplish...

Employing Arynes in Diels–Alder Reactions and Transition-Metal-Free Multicomponent Coupling and Arylation Reactions

Arynes are highly electrophilic reactive intermediates, which have been extensively utilized in various carbon–carbon and carbon–heteroatom bond-forming reactions. Recent developments in aryne chemistry have been devoted to transitionmetal-free reactions, which mainly include the initial addition of nucleophiles to arynes and subsequent trapping of the aryl anion intermediate with electrophiles [Eq. (1)]. If the nucleo-

Sachin Suresh Bhojgude

Papers

Employing Arynes in Diels–Alder Reactions and Transition-Metal-Free Multicomponent Coupling and Arylation Reactions

Arynes in Transition‐Metal‐Free Multicomponent Coupling Reactions

Employing Arynes in Transition-Metal-Free Monoarylation of Aromatic Tertiary Amines

Substrate-Controlled Selectivity Switch in the Three-Component Coupling Involving Arynes, Aromatic Tertiary Amines, and CO2.

Three-Component Coupling Involving Arynes, Aromatic Tertiary Amines, and Aldehydes via Aryl–Aryl Amino Group Migration