Potassium 2,2,5,7,8-pentamethylchroman-6-oxide: a rationally designed base for Pd-catalysed amination.

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.