Synthesis of new optically active cyanocyclopropanes as chiral dopants for ferroelectric liquid crystals

✍ Scribed by Tetsuo Kusumoto; Akiko Nakayama; Ken-ichi Sato; Tamejiro Hiyama; Sadao Takehara; Tadao Shoji; Masashi Osawa; Takeshi Kuriyama; Kayoko Nakamura; Toru Fujisawa

• Publisher: Elsevier Science
• Year: 1991
• Tongue: French
• Weight: 249 KB
• Volume: 32
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)92125-7

✦ Synopsis

Optically acttve 2-alkyl-I-aryl-I-cyanocyclopropanes

weye synthesized from 2-aryI-4-hydroxyalkanenitriles which in turn were obtained by the reaction of chiral 1,2epoxyalkanes with the carbanions derived from arylacetonitnles. Ferroelectric liquid crystals (FLCs) have been attracting much attention of scientists in academic and industrial research institutes, since Clark and Lagerwall suggested in 1980 that FLCs might be applicable to high-speed switching devices. 1) As the response time depends on the magnitude of spontaneous polarization (I's), various optically active compounds exhibiting a large Ps have been synthesized for chiral dopants. 2) We have designed chiral dopants which contain chiral center connected directly both to a polar group and to a core aromatic rings-h) and recently have found that cyano group is particularly pertinent as a polar group.5,6) We report herein the synthesis of the FLCs having an optically active cyclopropane ring like 1, wherein CN group is fixed perpendicular to the long axis of the molecule. a: (lR,2S) X= n-CBH170 -Q-&O0 R = n-C6HIJ be (lS,2S) II c (lR,2S