Recent Advances in Radical Coupling Strategies Enabled by 2‐Azaallyl Anions as Super‐Electron‐Donors

Abstract

Abstract Due to amine derivatives widely existing in numerous clinical medicines and bioactive compounds, their synthesis has received considerable attention over the past few decades. Traditional methods for the synthesis of amine derivatives largely relied on the reduction of nitroarenes, amides, hydrazines, nitriles, and azides. Recently, the discovery of 2‐azaallyl anions as super‐electron‐donors (SEDs) has opened up new possibilities for the construction of diverse carbon‐carbon and carbon‐heteroatom bonds through radical coupling strategies. This breakthrough highlights the potential of generating 2‐azaallyl radicals as versatile intermediates in organic synthesis. Then, hydrolysis of the coupling product can easily separate the corresponding amine derivatives. Thus, tremendous attention has been paid to the C−H functionalization of ketimines as an alternative strategy for the synthesis of amine derivatives. Herein, we comprehensively summarize the recent progress in radical coupling strategies enabled by 2‐azaallyl anions as SEDs. Their proposed mechanistic pathways, advantages, and limitations are also discussed in detail. 1. Introduction 2. C−C Bond Formation 2.1. Vinylation of Ketimines 2.2. Arylation of Ketimines 2.3. Alkylation of Ketimines 2.3.1. Methylation of Ketimines 2.3.2. Other Alkylation of Ketimines 3. C−X Bond Formation 3.1. C−P and C−S Bonds Formation 3.2. C−N and C−O Bonds Formation 4. Conclusions

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