Diastereoselective cyclization in chiral diarylethene crystals: polymorphism and selectivity.
[structure: see text] An optically active photochromic diarylethene, (S)-1-(2-methyl-5-phenyl-3-thienyl)-2-[2-methyl-5-(4-(3-methyl-1-penten-1-yl)phenyl)-3-thienyl]perfluorocyclopentene ((S)-1a), was synthesized. (S)-1a formed two crystalline phases, alpha- and beta-phases. The diarylethene underwent a photochromic reaction in solution and even in the single-crystalline phase. In solution, no diastereoselection was observed. On the other hand, in the beta-crystalline phase, only one diastereomer (S,R,R)-1b was produced. No such diastereoselection was observed in the alpha-crystalline phase.
Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581, Japan.
Satoshi
S
Yamamoto
Kenji
K
Matsuda
Masahiro
M
Irie