New Fluorine Substituted Liquid Crystal Containing Bicyclo[2.2.2]Octane Unit

Nonconjugated Hydrocarbons as Rigid‐Linear Motifs: Isosteres for Material Sciences and Bioorganic and Medicinal Chemistry

“…Fluorine substituents can reduce melting without total elimination of liquid crystal phase due to its small atom size and high electronegativity that modulate the physical properties of the molecule . A variety of linearly‐BCO‐connected LC were synthesized with fluorine‐substituted benzenes incorporated in different positions of the mesogenic core 203 – 204 (Figure ) . Results showed that when fluorine atoms were incorporated at the end or in the middle of the mesogenic core a decrease of melting and clearing point values was observed which either reduced the interval of the mesophase or removed the LC phase completely depending on the location and number of fluorine atoms.…”

“…The fluorinated BCO derivative 205 and benzene LCs showed that upon fluorination nematic behavior was eliminated for both compounds while their SmC and SmA phases were enhanced and for the BCO derivative induced SmA, smectic I (SmI) and smectic F (SmF) phases were observed . The key step in the synthesis of compound 205 involved the reaction of the BCO alcohol, 4‐(3,4‐difluorophenyl)bicyclo[2.2.2]octan‐1‐ol, with 1,3‐difluoro‐5‐propylbenzene in the presence of H 2 SO 4 .…”

Hindered Dialkyl Ether Synthesis via Electrogenerated Carbocations

“…Striking truncation of this sequence could be achieved by a 2-step sequence (22% overall, 27 h) involving electrochemical hydroxylation (with basic workup to hydrolyze the remaining ester), followed by decarboxylative Giese-type chemistry. The same logic could be applied to alcohol 76, of use as an intermediate in the liquid-crystal arena, that was previously synthesized in a 7-step sequence (8% overall yield, 62 h) 34 . Thus, a Ni-catalyzed decarboxylative Negishi coupling of 71, followed by hydrolysis and electrochemical hydroxylation, furnished 76 in only 3 steps (17 % overall).…”