Neopentyl Esters as Robust Linkers for Introducing Functionality to Bis-MPA Dendrimers

A series of neopentyl carboxylic acids bearing functionality amenable to click chemistry were prepared and then appended to high-generation bis-MPA dendrons via fluoride-promoted esterification. The nucleophilic stability of neopentyl and non-neopentyl dendrons in acidic to basic phosphate buffers was compared by monitoring degradation via quantitative H-1 nuclear magnetic resonance (NMR). The neopentyl periphery dendrons were found to be highly resistant to hydrolysis under all experimental conditions. The neopentyl groups also did not impede click functionalization onto the dendrons.