Reaction Profiling of Visible Light-Mediated [2+1] Dearomatization vs Alkylation of Electron-Rich Arenes with Aryldiazoacetates: Real-Time NMR Monitoring, Kinetics, and Computational Analysis

Abstract

Dearomative [2+1] reaction between electron-rich arenes and aryldiazoesters for the regioselective and diastereoselective synthesis of norcaradienes is reported. Strategic tuning of the electron density of the electron-rich arene prevents the usual alkylation reaction. Obtained meso norcaradienes are further desymmetrized into products with six contiguous stereogenic centres, while reactive functional groups allow for subsequent manipulation into more complex carbocycles. Profiling the reaction through the LED-NMR analysis gave kinetic insights to product formation, and unwanted side-reactions, and the influence of electron density profile on cyclopropanation vs alkylation in the key dearomative step is elucidated by theoretical analysis.