Synthesis of end-functionalized poly(methyl methacrylate) by organocatalyzed group transfer polymerization using functional silyl ketene acetals and α-phenylacrylates

The present study describes the alpha- and omega-end-functionalization of poly(methyl methacrylate)s (PMMAs) by organocatalyzed group transfer polymerization (GTP) using both functional silyl ketene acetal (SKA) initiators and alpha-phenylacrylate terminators. The syntheses of structurally defect-free alpha-end-functionalized PMMAs with hydroxyl, ethynyl, vinyl, and norbornenyl groups (HO-PMMA, HC C-PMMA, H2C CH-PMMA, and NB-PMMA, respectively) were achieved by either the N-(trimethylsilyl)bis(trifluoromethanesulfonyl)imide-( Me3SiNTf2-) or t-Bu-P-4-catalyzed GTP of MMA using functional trimethyl SKAs (1a-1d). On the other hand, the omega-end-functionalized PMMAs with ethynyl, hydroxyl, vinyl, and bromo groups (PMMA-C CH, PMMA-OH, PMMA-CH CH2, and PMMA-Br, respectively) were for the first time obtained by the Me3SiNTf2-catalyzed GTP of MMA followed by a termination reaction using functional alpha-phenylacrylates (2a-2d). All the polymerizations produced end-functionalized PMMAs with controlled molar masses, narrow dispersities, and defect-free polymer structures as designed. The quantitative incorporation of functionalities into the alpha- or omega-end of the PMMAs was confirmed by the H-1 NMR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) measurements.