Solubilizing influence of 2,7-Bis(trimethylsiyl) substitution on the fmoc residue

Nowick and co-workers described the synthesis of 2,6-di-tert-butyl-9-fluorenemethyloxycarbonyl group as a substitute for the Fmoc function in cases where the latter led to highly insoluble derivatives. It was shown for some systems that such substitution enhanced solubilities by 1-2 orders of magnitude.