20.500.12556/RUL-160080 Piperidine and piperazine analogs in action zinc(II)-mediated formation of amidines The catalytic activity of zinc(II) compounds was exploited in the nucleophilic addition of amines to nitriles to form amidines. The reaction systems comprised a Zn(II) starting material [Zn(quin)$_2$(H$_2$O)] (quin− = quinaldinate, an anion of quinaldinic acid), secondary cyclic amine, acetonitrile, and in some cases, methanol. Amines with additional heteroatoms in the ring (thiomorpholine, piperazine) or ring substituents (piperidine derivatives, piperazine derivatives) with different steric and electronic effects were used. The aim of the study was to determine how the nature of the amine affects the formation of amidines. Different types of Zn(II) products were obtained: mono- or diamine complexes, amidine complexes, and also an ionic compound with a protonated amine. In one case, the amidine itself crystallized. A Zn(II) complex with acetamidine was also obtained. Acetamidine was formed from acetonitrile and ammonia, which most likely originated from the hydrolysis of acetonitrile under harsh reaction conditions. The hydrolysis could terminate at the acetamide step, which was confirmed by the isolation of a cocrystal containing acetamide. In the case of piperazine (pz), a polymeric compound with the composition [Zn(quin)$_2$(pz)]$_n$ was isolated regardless of the reaction conditions. The same coordination polymer was also observed to form in 1-methylpiperazine, 1-ethylpiperazine, and 1-acetylpiperazine reaction systems, containing piperazine as an inherent impurity. This was unambiguously confirmed by the crystal structure of a cocrystal, [Zn(quin)$_2$(1-Acpz)$_2$]·[Zn(quin)$_2$(pz)]$_n$·4CH$_3$CN, which formed in the 1-acetylpiperazine (1-Acpz) reaction system. quinaldinate piperazine cyclic amines amidines zinc(II) crystal structure kinaldinat piperazin ciklični amini amidini cink(II) kristalne strukture true false true Angleški jezik Slovenski jezik Članek v reviji 2024-08-16 12:13:31 2024-08-16 12:13:31 2024-08-17 03:55:12 0000-00-00 00:00:00 2024 0 0 Str. 8844-8859 iss. 19 Vol. 48 21 May 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 547.85:546.47:544.1 1369-9261 10.1039/D4NJ00235K 195465475 RAZ_Podjed_Nina_2024.pdf RAZ_Podjed_Nina_2024.pdf 1 4BA7E7B9E5DB64FBE48E21A26ACF39CE 29cee5fae4706845e1189b323d9ed80dd41cb620014dbc18d69c3273b08d549c ecd48e24-5bb8-11ef-8f74-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=188530 https://pubs.rsc.org/en/content/articlelanding/2024/nj/d4nj00235k 1 01e52205-5bb8-11ef-8f74-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=188529 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0