10381-82-5Relevant articles and documents
Synthesis of palladium complexes with anionic N,NR- or neutral NH,NR-theophylline-derived NHC ligands
Hahn, F. Ekkehardt,Hervé, Alexandre,Jahnke, Mareike C.,Kampert, Florian
, (2021)
Four C8-halogenated theophyllines (1–4) featuring N7-methyl or N7-allyl and C8-chloro or C8-bromo substituents have been prepared. The halogenotheophyllines react with [Pd(PPh3)4] in an oxidative addition to give complexes of type trans-[Pd(theophyllinato)X(PPh3)2] (trans-[5]–trans-[8]). The protonation of the unsubstituted theophyllinato ring-nitrogen atom to give the pNHC complexes was achieved either by performing the oxidative addition of 1 in the presence of NH4BF4 to give complex trans-[9]BF4 or by N-protonation of the coordinated theophyllinato ligand in trans-[6]–trans-[8] with HBF4·Et2O to give complexes trans-[10]BF4–trans-[12]BF4. The molecular structures of trans-[5], trans-[7], trans-[9]BF4, trans-[11]BF4 and trans-[12]BF4 were determined by X-ray diffraction showing significant differences of comparable metric parameters in the theophylline-derived five-membered diaminoheterocycles. No interaction of the N-allyl substituents with the metal center was observed.
Synthetic Transformations of Sesquiterpene Lactones. 11.* Conjugates Based on Caffeine and Eudesmanolides with N-Containing Linkers
Reshetnikov,Patrushev,Shults
, p. 855 - 860 (2020)
8-(Aminoalkylamino)caffeine or 8-(piperazinyl)caffeine were formed in high yields by reacting 8-bromo- or 8-chlorocaffeine with linear and cyclic diamines using microwave-assisted organic synthesis. These amines were highly reactive in Michael reactions with sesquiterpene lactones containing active methylene groups. Conjugates with caffeine and eudesmanolide moieties bonded by a N-containing linker were synthesized.
8-Ethynylxanthines as promising antiproliferative agents, angiogenesis inhibitors, and calcium channel activity modulators
Arsenyan, Pavel,Vasiljeva, Jelena,Domracheva, Ilona,Kanepe-Lapsa, Iveta
, p. 776 - 785 (2020/07/27)
[Figure not available: see fulltext.] Synthetic procedures for the preparation of 8-ethynylxanthines by treating 8-bromocaffeine and 8-bromopentoxifylline with terminal acetylenes were elaborated. Certain ethynylxanthine derivatives exhibit high in vitro antiproliferative activity against a panel of cancer cell lines, matrix metalloproteinase and in vitro angiogenesis inhibitory activity. Ca2+ channel blocking and agonist activity of the synthesized ethynylxanthines was discussed based on data obtained on the H9C2, SH-SY5Y, and A7R5 cell lines.