Find in Library

<i>N</i>-Sulfonyl-activated aziridines are known to undergo anionic-ring-opening polymerizations (AROP) to form polysulfonyllaziridines. However, the post-polymerization deprotection of the sulfonyl groups from polysulfonyllaziridines remains challenging. In this report, the polymerization of <i>tert</i>-butyl aziridine-1-carboxylate (<b>BocAz</b>) is reported. <b>BocAz</b> has an electron-withdrawing tert-butyloxycarbonyl (BOC) group on the aziridine nitrogen. The BOC group activates the aziridine for AROP and allows the synthesis of low-molecular-weight poly(<b>BocAz</b>) chains. A ¹³C NMR spectroscopic analysis of poly(<b>BocAz</b>) suggested that the polymer is linear. The attainable molecular weight of poly(<b>BocAz</b>) is limited by the poor solubility of poly(<b>BocAz</b>) in AROP-compatible solvents. The deprotection of poly(<b>BocAz</b>) using trifluoroacetic acid (TFA) cleanly produces linear polyethyleneimine. Overall, these results suggest that carbonyl groups, such as BOC, can play a larger role in the in the activation of aziridines in anionic polymerization and in the synthesis of polyimines.