Abstract
meso-Tetrakis(2-pyridyl)-porphyrin (2-PyP) was tetra-N-alkylated with three different α-bromoacetamides to generate a series of water-soluble N-alkylpyridinium porphyrins (1-3). The product mixtures showed a marked preference for the formation of the ααββ atropisomer. With α-bromo N-n-butylacetamide, the corresponding ααββ 2-tetrakis (N-n-butylacetamido)-pyridyl porhyrin (2-TnBuPyP, 3) was obtained in 69% isolated yield in a single step. Prolonged heating lead to equilibration of the rotational isomers for the less bulky alkyl groups, indicating that the observed preference is a kinetic effect. The intermediate products for the N-bornyl case were identified by LC/ESI-MS to deduce an explanation for the observed nonstatistical selectivity.
Original language | English (US) |
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Pages (from-to) | 1818-1821 |
Number of pages | 4 |
Journal | Journal of Organic Chemistry |
Volume | 72 |
Issue number | 5 |
DOIs | |
State | Published - Mar 2 2007 |
All Science Journal Classification (ASJC) codes
- Organic Chemistry