Cross Redox Coupling of Aryl-Aldehydes and <i>p</i>-Benzoquinone
作者:Anima Bose、Prasenjit Mal
DOI:10.1021/acs.joc.5b02175
日期:2015.11.6
unprecedented Cross Redox Coupling (CRC) reaction catalyzed by Cu(OAc)2·H2O. As a proof-of-concept, directcoupling of aromatic aldehydes (or alcohols) and p-benzoquinone led to an ester in the presence of the Cu(II)–TBHP combination. During the coupling process, the C–H bond of the aldehydes was converted directly to a C–O bond. Mechanistically, we propose that the reaction proceeded via a radical pathway
The present invention relates to compounds that have ultraviolet light absorbing properties, and which can also have mesogenic properties. The present invention also relates to compositions that include one or more such compounds, and to articles of manufacture that include one or more such compounds, such as optical elements that include an optical substrate and a layer that includes at least one compound of the present invention.
Compounds that have ultraviolet light absorbing properties, and which can also have mesogenic properties. Compositions that include one or more such compounds. Articles of manufacture that include one or more such compounds, such as optical elements that include an optical substrate and a layer that includes at least one such compound.
The transformation kinetics of a series of liquid-crystallines based on 1,4-phenylene 4-n-alkybenzoate-4-allyloxybenzoate (PABAOB) was studied by nonisothermal methods using differential scanning calorimetry. These determinations led to the values of activation energy of transformation from 691.3 to 628.3 kJ/mol, respectively The values of the Avrami exponent n were from 3.0 to 2.6. The values of transformation activation energy decreased with the ascending of alkyl. The result shows that the process of transformation of PABAOB is a constant number of nuclei growing in three dimensions at constant rate and the crystal growth being controlled probably by a diffusion process. (C) 1997 John Wiley & Sons, Inc.
Liquid crystal composition containing an optical active compound and liquid crystal electro-optical element