SYNTHESIS AND THERMAL PROPERTIES OF TWIN DIMERS CONTAINING CYANOSTILBENE GROUPS AS A MESOGENIC GROUP
摘要:
Twin dimers (TDs) with a different linking group (ester or ether) between the mesogenic group (cyanostilbene moiety) and the flexible spacer were synthesized to clarify the effect of the linking group on the mesomorphic properties. The sequence of the ester linking group and the position of the cyano group in the mesogenic core made an important contribution to the thermal properties of the twin dimers. A remarkable odd-even effect in the phase transition temperatures and entropy changes from a nematic phase to an isotropic fluid was observed for all the synthesized twin dimers.
Transition-Metal-Free and Selective Deconstructive Carbonyl Olefination of α-Hydroxy Ketones: A Complementary Approach to Knoevenagel Reaction
作者:Anil Kumar、Sandeep Sandeep、Vaneet Saini、Chayawan Chayawan、Ganga R. Chaudhary、Paloth Venugopalan
DOI:10.1055/a-2114-7802
日期:2023.10
While the carbonylolefination has been extensively studied and well documented, use of α-hydroxy ketones as precursors for the carbonylolefination is not reported, till date. Herein, a transition-metal-free and selective Knoevenagel-type deconstructive carbonylolefination of α-hydroxy ketones using arylacetonitriles under mild reaction conditions is presented. The reaction affords valuable scaffolds