Table 2. Twist sense control in o-imine o-phenylenes a .
Compound | Conf. | Pop. b | de b | Twist sense c |
(R)-oP6(o-tBu) | ii | 33% | 88% | P |
io | 20% | 42% | P | |
oo | 47% | 0% | — | |
(R)-oP6(o-iPr) | ii | 25% | 68% | P |
io | 20% | 10% | P | |
oo | 55% | 38% | M | |
(S)-oP6(o-Et) | ii | 25% | 20% | M |
io | 20% | 16% | P | |
oo | 55% | 58% | P | |
(R)-oP6(o-Cy) | ii | 24% | 68% | P |
io | 17% | 8% | P | |
oo | 59% | 54% | M | |
(S)-oP6(o-Bo) | ii | 65% | 88% | M |
io | 18% | 14% | M | |
oo | 18% | 52% | P | |
(S)-oP6(o-Ph) | ii | 28% | 74% | n.d. |
io | 23% | 36% | n.d. | |
oo | 49% | 16% | n.d. |
aConf. = conformer, Pop. = population.
bDetermined from 1H NMR deconvolution at 278 K (CDCl3). Only the perfectly folded state was considered.
cAssigned as discussed in the text.