LCrK (Cat. 2) catalysed PTA ROCOP with 3-Me/3-R-substituted oxetanesa.
| Runb | R | t [h] | Conv.a [%] | Alt.c [%] | M n d [kDa] (Ð) |
|---|---|---|---|---|---|
| #1 | Me | 19 | 99 | 99 | 11.4 (1.2) |
| #2 | CH2OEt | 60 | 75 | 99 | 28.4 (2.2) |
| #3* | CH2OBn | 72 | 80 | 97 | 9.8 (1.2) |
| #4 | CH2OAllyl | 220 | 60 | 99 | 16.2 (1.6) |
a
ROCOP conducted at 80 °C or *120 °C with 1 eq. LCrK: 1000 eq. 3-Me,3′-R-Oxetane: 1000 eq. PTA.
b
Conversion calculated by comparing the relative integrals in the normalised 1H NMR spectrum (CDCl3, 400 MHz) of aromatic resonances due to polymer versus unconsumed PTA.
c
Relative integrals in the 13C NMR spectrum (CDCl3, 126 MHz) from carbonyl resonances due to alternating ester-alt-thioester links compared to other carbonyl resonances.
d
Determined by GPC (gel permeation chromatography) measurements conducted in THF, using narrow MW polystyrene standards to calibrate the instrument.