119754-13-1Relevant academic research and scientific papers
A photolabile protection strategy for terminal alkynes
Gschneidtner, Tina A.,Moth-Poulsen, Kasper
, p. 5426 - 5429 (2013/09/23)
We present a strategy for photolabile protection of terminal alkynes. Several photo-caged alcohols were synthesized via mild copper(II)-catalyzed substitution between tertiary propargylic alcohols and 2-nitrobenzyl alcohol to build up robust, base stable o-nitrobenzyl (NB) photo-cleavable compounds. We compare the new photolabile protecting group with the commonly used alkyne protecting group, 2-methyl-3-butyn-2-ol and the results show that NB ethers are stable under the cleaving conditions for the cleavage of methylbutynol protected alkynes. Additionally, we present the synthesis of photo-cleavable NB derivatives containing thiol groups that can serve as agents for photoinduced surface functionalization reactions.
Liquid crystal dimers derived from naturally occurring chiral moieties: synthesis and characterization
Yelamaggad, Channabasaveshwar V.,Shanker, Govindaswamy
, p. 3760 - 3771 (2008/09/20)
Naturally occurring cholesterol and α-chloroalkanoyl units derived from natural α-amino acids (l-valine, l-leucine, and l-isoleucine) have been utilized to prepare three different series of nonsymmetric liquid crystal dimers. Tolane (diphenylacetylene), w
Convenient syntheses of m- and p-ethynylphenols
Lai, Guo-Qiao,Liu, Shi-Ling,Xu, Jin-Feng,Shen, Yong-Jia
, p. 203 - 204 (2007/10/03)
m-lodophenol (4a) was found to couple with 2-methylbut-3-yn-2-ol (5) in the presence of PdCl2-CuI-Ph3P-in triethylamine to afford 3-(3-hydroxy-3-methylbut-1-ynyl)phenol(6a), which was conveniently converted into m-ethynylphenol (7a). Under the same conditions, p-iodophenol did not couple with 5. However, p-iodo-1-[(tetrahydro-2H-pyran-2-yl)oxy]benzene (4b) did react with 5 to afford 1-[(tetrahydro-2H-pyran-2-yl)oxy]-4-[2-hydroxy-2-methyl- 4-but-3-ynyl]benzene (6b), which was similarly converted into 1-[(tetrahydro-2H-pyran-2-yl)oxy]-4-ethynylbenzene (7b) with loss of acetone. Removal of the tetrahydropyranyl protecting group from 7b furnished p-ethynylphenol (8).
High birefringence phenylacetylene liquid crystals with low viscosity
Sekine, Chizu,Fujisawa, Koichi,Iwakura, Kazunori,Minai, Masayoshi
, p. 711 - 718 (2007/10/03)
We have synthesized new high Δ n 3-ring phenylacetylene(3PA) liquid crystals which have substituent groups with core center phenyl ring and investigated the effects of substitution on physical properties. Nematic range and viscosity were improved remarkab
A novel calamitic liquid crystalline oligomer composed of three non- identical mesogenic entities: Synthesis and characterization
Yelamaggad,Hiremath,Shankar Rao,Krishna Prasad
, p. 57 - 58 (2007/10/03)
The synthesis and evaluation of the mesomorphic properties of the first trimesogen consisting of three non-identical calamitic mesogenic entities have been described.
Synthesis of Some Substituted Dimethyl and Diethyl 4-(Phenylethynyl)-2,6-pyridinedicarboxylates
Takalo, Harri,Kankare, Jouko,Haenninen, Elina
, p. 448 - 454 (2007/10/02)
Substituted dimethyl and diethyl 4-(phenylethynyl)-2,6-pyridinedicarboxylates were prepared by coupling reactions between dialkyl 4-halo-2,6-pyridinedicarboxylates and terminal arylacetylenes in the presence of an organopalladium catalyst and copper(I) iodide in a suitable solvent system.The terminal acetylenes needed in this work were synthesized from the corresponding aryl halides using either (trimethylsilyl)acetylene or 2-methyl-3-butyn-2-ol followed by deprotection of the triple bond, depending on the nature of the compound in question.
