| Abstract | U cilju nastavka proučavanja utjecaja heterocikličke jezgre na fotokemijsko ponašanje supstituiranih o-divinilbenzena razvijena je sinteza novih supstituiranih o-divinilbenzena s piridinskom jezgrom. Wittigovom reakcijom sintetizirani su novi piridinski produkti 2-2[(2-vinilfenil)etenil]piridin (1), 3-2[(2-vinilfenil)etenil]piridin (2) i 4-2[(2-vinilfenil)etenil]piridin (3) kao smjese geometrijskih izomera. Iz smjesa izomera uspješno su izolirani cis- i trans-izomeri koristeći kolonsku i tankoslojnu kromatografiju te su isti u potpunosti spektroskopski opisani. Svi novi sintetizirani derivati 1-3 podvrgnuti su fotokemijskim reakcijama na 300 nm u uvjetima sa i bez kisika u smjeru priprave novih bicikličkih struktura. Početni spojevi pokazali su različito fotokemijsko ponašanje. Fotoreakcija spoja 1 dovodi do zatvaranja u ciklizacijski spoj 7-etenil-benzo[f]kinolin (6), a uz njega izolirana su i opisana i dva intermedijara 7-etenil-10aH,10bH-cikloheksa[f]kinolin (4) i 7-etenil-1H,4H-benzo[f]kinolin (5). Uz ciklizacijski produkt nastala su dva produkta reakcijama cikloadicije i to biciklički produkt 2-(triciklo[6.1.1.02,7]deka-2,4,6-trien-9-il)piridin (7) te 3-azatetraciklo-[7.6.1.02,7.010,15]heksadeka-4-6,10(15),11,13-pentaen (8). Osvjetljavanjem spoja 2 dolazi do stvaranja većinskog ciklizacijskog spoja 7-etenil-benzo[f]izokinolina (9) (60 %) i manjinskog ciklizacijskog spoja 7-etenil-benzo[h]kinolina (10) (20 %) te bicikličkog produkta 3-(triciklo[6.1.1.02,7]deka-2,4,6-trien-9-il)piridina (11) (8 %). Osvjetljavanjem spoja 3 pokazalo se kako on uopće ne reagira već isključivo dolazi do reakcije trans-cis izomerizacije. S ciljem upotpunjavanja našeg razumijevanja fotokemijskih procesa koji se odvijaju, izračunali smo kvantna iskorištenja korištenjem ferioksalatog aktinometra. Polazni spojevi 1-3 kao i njihovi fotoprodukti okarakterizirani su modernim spektroskopskim metodama (jednodimenzionalni i dvodimenzionalni NMR, UV, IR i MS). Novi potencijalni farmakološki interesantni spojevi dobiveni su jednostavnim pristupom koristeći svjetlo kao reagens i pogodni su za daljnje transformacije i funkcionalizacije. |
| Abstract (english) | As a continuation of the study of the effect of the heterocyclic ring on the photochemical behavior of o-divinylbenzenes, a syntheses of new derivatives with pyridine as a heterocycle were developed. New derivatives 2-2[(2-vinylphenyl)ethenyl]pyridine (1), 3-2[(2-vinylphenyl)ethenyl]pyridine (2) and 4-2[(2-vinylphenyl)ethenyl]pyridine (3) were synthesized by Wittig reaction as mixtures of isomers. Both of the isomers, cis- and trans-, were isolated by chromatographic and thin layer chromatographies and completely spectroscopically analyzed. All of the derivatives 1-3 were irradiated at 300 nm to see if they would react and give new bicyclic products. Derivatives of 2-, 3- and 4-pyridine showed versatile reactivity in given conditions. Photoreaction of 2-pyridine derivative (1) gave, by cyclisation reaction, compound 7-vinylbenzo[f]quinoline (6). We were also able to isolate 2 intermediates of this process, compounds 7-vinyl-10a,10b-dihydrobenzo[f]quinoline (4) and 7-vinyl-1,4-dihydrobenzo[f]quinoline (5). This derivative also gave, by reaction of cycloaddition, two new bicyclic compounds, 2-(tricyclo[6.1.1.02,7]deca-2,4,6-trien-9-yl)pyridine (7) and 3-azatetracyclo[7.6.1.02,7.010,15]hexadeca-4-6,10(15),11,13-pentaene (8). Irradiation of compound 2 gave one major and a minor product. Major product was 7-vinylbenzo[f]isoquinoline (9) (60 %) and the minor 7-vinylbenzo[h]quinoline (10) (20 %). These derivatives also gave a cycloaddition product 3-(tricyclo[6.1.1.02,7]deca-2,4,6-trien-9-yl)pyridine (11) (8 %). Irradiation of 4-pyridine derivative in various conditions showed that this compound did not react in other than in reactions of photoisomerisation. To enrich our understanding of the photochemical process taking place we calculated quantum yields by utilization of ferrioxalate actinometer. All of the compounds were characterized by spectroscopic methods (one- and two-dimensional NMR, UV, IR and MS). |
