1560-54-9Relevant articles and documents
Supramolecular Recognition of Quaternary Phosphonium Cations
Walsh, Mark P.,Kitching, Matthew O.
, (2021/12/06)
The modes of supramolecular recognition of quaternary phosphonium cations mediated by 1,1′-bi-2-naphthol (BINOL) are identified and characterized. In contrast to our previous work on ammonium cations, the recognition of the quaternary phosphonium cations via the formation of a PR4+·Br–·BINOL ternary complex was found to be mediated by a hydrogen bond from an α-carbon center of the phosphonium cation, encapsulation within a continuous hydrogen bond network between the halide–BINOL network, or a combination of these effects working in tandem. The solid state structures of these ternary complexes were analyzed by X-ray crystallography, aided by Hirshfeld surface analysis, to confirm the presence of characteristic intermolecular interactions for the identified modes. In all cases, the quaternary phosphonium cation acts as a hydrogen bond donor (HBD) in these supramolecular interactions, and thus this is the key to the recognition process with BINOL. The characterization of such mechanisms offers insight into the supramolecular and crystal engineering communities in the future design of agents capable of the supramolecular recognition of phosphonium cations and their abstraction from the solution phase.
Substituted dienes prepared from betulinic acid – Synthesis, cytotoxicity, mechanism of action, and pharmacological parameters
Frydrych, Ivo,Urban, Milan,?arek, Jan,Benická, Sandra,D?ubák, Petr,Gurská, Soňa,Hajdúch, Marián,Kotulová, Jana,Li?ková, Barbora,Olejníková, Denisa,Pokorny, Jan
, (2021/07/28)
A set of new substituted dienes were synthesized from betulinic acid by its oxidation to 30-oxobetulinic acid followed by the Wittig reaction. Cytotoxicity of all compounds was tested in vitro in eight cancer cell lines and two noncancer fibroblasts. Almost all dienes were more cytotoxic than betulinic acid. Compounds 4.22, 4.30, 4.33, 4.39 had IC50 below 5 μmol/L; 4.22 and 4.39 were selected for studies of the mechanism of action. Cell cycle analysis revealed an increase in the number of apoptotic cells at 5 × IC50 concentration, where activation of irreversible changes leading to cell death can be expected. Both 4.22 and 4.39 led to the accumulation of cells in the G0/G1 phase with partial inhibition of DNA/RNA synthesis at 1 × IC50 and almost complete inhibition at 5 × IC50. Interestingly, compound 4.39 at 5 × IC50 caused the accumulation of cells in the S phase. Higher concentrations of tested drugs probably inhibit more off-targets than lower concentrations. Mechanisms disrupting cellular metabolism can induce the accumulation of cells in the S phase. Both compounds 4.22 and 4.39 trigger selective apoptosis in cancer cells via intrinsic pathway, which we have demonstrated by changes in the expression of the crucial apoptosis-related protein. Pharmacological parameters of derivative 4.22 were superior to 4.39, therefore 4.22 was the finally selected candidate for the development of anticancer drug.
Radical-Mediated Heck-Type Alkylation: Stereoconvergent Synthesis of Functionalized Polyenes
Zhang, Hong,Wu, Xinxin,Wei, Yunlong,Zhu, Chen
supporting information, p. 7568 - 7572 (2019/10/02)
The stereospecific synthesis of polyenes is of great synthetic value. Disclosed herein is a new, efficient, stereoconvergent approach for the synthesis of functionalized polyenes via a radical-mediated Heck-type alkylation. The easily accessed Z- and E-mixed alkenes are harnessed as starting material, leading to a unique stereoisomer of polyenes. In addition, the transformation features mild reaction conditions and broad functional group compatibility. A variety of valuable 1,3-dienes and 1,3,5-trienes are afforded in useful yields.
