Related Experiment Video
Updated: May 26, 2026

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
Potassium 2,2,5,7,8-pentamethylchroman-6-oxide: a rationally designed base for Pd-catalysed amination
1Department of Chemistry, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada.
Abstract:
This base is just right! A new base, potassium 2,2,5,7,8-pentamethylchroman-6-oxide, for Pd-catalysed amination has been rationally designed that has sufficient basicity to efficiently deprotonate the intermediate aryl palladium ammonium complex, leading to far better rates than obtained with carbonate, which is known to be very mild. At the same time, this new base possesses minimal nucleophilicity to mitigate the degradation of base-sensitive functional groups in the starting materials and products, such as is commonly seen with potassium or sodium tert-butoxide.
Related Concept Videos
Factors Affecting α-Alkylation of Ketones: Choice of Base
The reaction involving bases like EtO− whose conjugate acid EtOH (pKa = 15.9) is stronger than the ketone (pKa = 19.2) results in an equilibrium mixture with higher ketone concentration. As a consequence, side reactions...
α-Alkylation of Ketones via Enolate Ions
Base-Promoted α-Halogenation of Aldehydes and Ketones
Basicity of Aliphatic Amines
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates higher...
Aldol Condensation with β-Diesters: Knoevenagel Condensation
Preparation of Amines: Reductive Amination of Aldehydes and Ketones

