64419-24-5Relevant articles and documents
New variants of polymorphism in banana-shaped mesogens with cyano-substituted central core
Wirth,Diele,Eremin,Pelzl,Grande,Kovalenko,Pancenko,Weissflog
, p. 1642 - 1650 (2001)
A new series of achiral five-ring banana-shaped compounds is presented which exhibit a cyano substituent in the 4-position of the central core. It follows from X-ray investigations and from NMR, microscopical and electro-optical measurements that all members of the series do not only form the chiral B2 phase characteristic of a bent molecular shape, but also SmA and SmC (in one case also nematic) phases. The electro-optical studies on the B2 phase prove an antiferroelectric ground state which can be switched into ferroelectric states. On the base of the experimental data plausible structure models have been proposed.
Lewis acid-promoted site-selective cyanation of phenols
Yang, Wen,Zhang, Wu,Zhao, Wanxiang
, p. 4604 - 4609 (2020/07/04)
An efficient Lewis acid-promoted site-selective electrophilic cyanation of 3-substituted and 3,4-disubstituted phenols has been developed. The cyanation reactions using MeSCN as the cyanating reagent proceeded efficiently to afford a wide range of 2-hydroxybenzonitriles with high efficiency and excellent regioselectivity. This protocol could provide a practical method for the synthesis and modification of biologically active molecules.
Metal-Free Regioselective Monocyanation of Hydroxy-, Alkoxy-, and Benzyloxyarenes by Potassium Thiocyanate and Silica Sulfuric Acid as a Cyanating Agent
Sardarian, Ali Reza,Dindarloo Inaloo, Iman,Modarresi-Alam, Ali Reza,Kleinpeter, Erich,Schilde, Uwe
, p. 1748 - 1756 (2019/02/05)
A novel and efficient metal- and solvent-free regioselective para-C-H cyanation of hydroxy-, alkoxy-, and benzyloxyarene derivatives has been introduced, using nontoxic potassium thiocyanate as a cyanating reagent in the presence of silica sulfuric acid (SSA). The desired products are obtained in good to high yields without any toxic byproducts.
Development of Polar Order by Liquid-Crystal Self-Assembly of Weakly Bent Molecules
Alaasar, Mohamed,Prehm, Marko,Poppe, Silvio,Tschierske, Carsten
, p. 5541 - 5556 (2017/04/27)
Organic ferroelectrics are of growing importance for multifunctional materials. Here we provide an understanding of the distinct stages of the development of sterically induced polar order in liquid-crystalline (LC) soft matter. Three series of weakly bent molecules derived from 4-cyanoresorcinol as the bent core unit with laterally fluorinated azobenzene wings have been synthesized, and the effects of the position of fluorine substitution, alkyl-chain length, and temperature on the LC self-assembly and polar order were studied. In the LC phases a paraelectric–ferroelectric transition took place as the size of the polar domains gradually increased, thereby crossing a permittivity maximum, similar to inorganic solid-state ferroelectrics. An increase in polar coherence length simultaneously led to a transition from synpolar to antipolar domain correlation in the high-permittivity paraelectric range. Associated with the emergence of polar order was the development of a tilted organization of the molecules and a growing coherence of tilt. This led to a transition from non-tilted via tilt-randomized uniaxial to long-range-tilted biaxial smectic phases, and to surface-stabilized symmetry breaking with the formation of chiral conglomerates and field-induced tilt. Moreover, there is a remarkably strong effect of the position of fluorination; polar order is favored by peripheral core substitution and is suppressed by inside-directed fluorination.
Perfluoroalkanosulfonyl fluoride: A useful reagent for dehydration of aldoximes to nitriles
Yan, Zhao-Hua,Tian, Huan,Zhao, Dong-Dong,Jin, Hong-Ai,Tian, Wei-Sheng
, p. 96 - 98 (2016/01/25)
The reaction of a variety of aldoximes with perfluoroalkanosulfonyl fluoride in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in dichloromethane smoothly generated the corresponding nitriles in 70%-95% yields.
Discovery of phenoxybutanoic acid derivatives as potent endothelin antagonists with antihypertensive activity
Cai, Jin,Liu, Ligang,Hong, Kwon Ho,Wang, Peng,Li, Lushen,Cao, Meng,Sun, Chunlong,Wu, Xiaoqing,Zong, Xi,Chen, Junqing,Ji, Min
, p. 657 - 667 (2015/02/19)
A series of phenoxybutanoic acid derivatives were synthesized and tested for their antagonistic activity on the contraction of the rat thoracic aortic ring induced by endothelin-1. Preliminary screening results showed that 6e and 6g with benzoheterocycles demonstrated significant antagonistic activities when compared to the reference compound BQ123. The results from additional assays for the binding affinity and selectivity for endothelin receptors showed that 6e was a selective ETA antagonist with a nanomolar IC50. Moreover, 6e was effective in relieving hypoxia-induced pulmonary arterial hypertension and right ventricular weight ratio. Therefore, 6e may have potential for further development as a therapeutic agent for the treatment of cardiovascular diseases.
4-cyanoresorcinol-based bent-core mesogens with azobenzene wings: Emergence of sterically stabilized polar order in liquid crystalline phases
Alaasar, Mohammed,Prehm, Marko,May, Kathrin,Eremin, Alexey,Tschierske, Carsten
, p. 1703 - 1717 (2014/04/03)
A new series of azobenzene containing bent-core molecules incorporating 4-cyanoresorcinol as the central core unit exhibiting cybotactic nematic, rectangular, columnar, and different types of tilted smectic (SmC) phases are synthesized. The mesophase behavior and phase structures are characterized in bulk and freely suspended films using a variety of experimental techniques. Depending on the chain length and temperature a series of different mesophases is observed in these compounds, ranging from cybotactic nematic via paraelectric SmC phases, polarization randomized SmCsPR phases to ferroelectric and antiferroelectric SmC phases, associated with increasing size and correlation length of the polar domains. Spontaneous formation of chiral domains is observed in the paraelectric SmC and the SmCsPR phases and discussed in relation with superstructural chirality, bend elastic constants, and surface effects. Development of polar order in tilted smectic liquid crystalline phases (SmC) of bent-core mesogens is found to take place with increasing polar domain size in a series of distinct phases via a paraelectric and a new randomized polar SmC phase (SmCsPR) to a ferroelectric phase, which then becomes modulated and finally changes to an antiferroelectric phase.
NOVEL COMPOUND HAVING SKIN-WHITENING, ANTI-OXIDIZING AND PPAR ACTIVITIES AND MEDICAL USE THEREFOR
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Paragraph 0293-0295, (2014/02/16)
Provided are a novel compound having skin-whitening, anti-oxidizing and PPAR activities and a medical use thereof, and the compound has skin-whitening activities for the suppression of tyrosinase, and accordingly, is useful for use in skin-whitening pharmaceutical composition or cosmetic products; has anti-oxidant activities, and accordingly, is useful for the prevention and treatment of skin-aging; and has PPAR activities, and in particular, PPARα and PPARγ activities, and accordingly, is useful for use in pharmaceutical compositions or health foods which are effective for the prevention and treatment of obesity, metabolic disease, or cardiovascular disease.
Heterogeneous catalytic method for the conversion of aldoximes into nitriles using molecular sieve modified with Copper(II)
Kiss, Arpad,Hell, Zoltan
supporting information, p. 1778 - 1786 (2013/05/22)
A simple heterogeneous metal-catalyzed method was developed for the transformation of aldoximes into nitriles. Molecular sieve (4 A) modified with copper(II) proved to be an efficient catalyst for the conversion. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
Effects of chain branching and chirality on liquid crystalline phases of bent-core molecules: Blue phases, de Vries transitions and switching of diastereomeric states
Ocak, Hale,Bilgin-Eran, Belkiz,Prehm, Marko,Schymura, Stefan,Lagerwall, Jan P. F.,Tschierske, Carsten
scheme or table, p. 8266 - 8280 (2012/03/10)
Bent-core molecules based on a resorcinol bisbenzoate core with a series of distinct substituents in different positions at the central resorcinol core have been synthesized and characterized. The focus is on the effect of branched terminal groups in the racemic and chiral forms on the mesomorphic properties. These were investigated by differential scanning calorimetry, optical polarizing microscopy, X-ray diffraction, electro-optic and dielectric methods. Only bent-core mesogens derived from 4-cyanoresorcinol exhibit liquid crystalline phases and the mesophases of these compounds are strongly influenced by the branching and enantiomeric composition of the terminal chains. Depending on the structure of the rod-like wings and the enantiomeric composition, cybotactic nematic phases (NcybC), BPIII-like isotropic mesophases (BPIII cybC*) and various polar and apolar smectic phases (SmA, SmC, SmC*, SmCsPA, SmCsPA*) are formed. For one compound, a de Vries type smectic phase is observed and it appears that with decreasing temperature, order develops in two steps. First, at the SmA to SmC transition, the tilt direction becomes long range ordered and in a second step a long range ordering in bend direction takes place. Hence, for the optically active compound a transition from chirality induced polar switching to bend induced (shape induced) antiferroelectricity takes place. In this SmCsPA* phase a homogeneous layer chirality is induced under an applied electric field which interacts with the fixed molecular chirality leading to the energetically favoured diastereomeric state and giving rise to a field direction dependent uniform tilt director orientation. Field reversal induces a flipping of the layer chirality, which first leads to the less favorable diastereomeric state, and then this slowly relaxes to the more stable one by a spontaneous reversal of the tilt direction.
