Synthesis of 2‐Acetylbenzonitriles and Their Reactivity in Tandem Reactions with Carbon and Hetero Nucleophiles: Easy Access to 3,3‐Disubstituted Isoindolinones

2‐Acetylbenzonitriles have been conveniently synthesized by the oxidation of the respective 2‐ethylbenzonitriles, combining in a one‐pot procedure radical bromination and hydrolysis reactions. The obtained ketones reacted under very mild conditions with carbon and hetero nucleophiles to give a wide range of 3,3‐disubstituted isoindolinones in yields of 80–99 % by a tandem process consisting of an addition step and a subsequent Dimroth‐type rearrangement. Among the tested nucleophiles, the addition of water in the presence of a catalytic amount of KOH allowed a convenient access to an unprecedented variety of novel 3‐hydroxy‐3‐methylisoindolinones.