20.500.12556/RUL-109868 Aerobno jodohalogeniranje alkenov katalizirano z dušikovimi oksidi Aerobic iodohalogenation of alkenes catalysed by nitrogen oxides Eden izmed preferenčnih ciljev sodobne organske sinteze je razvoj okolju sprejemljivejših sinteznih metod. Osrednja tema raziskovanja diplomskega dela je bilo zato raziskati aerobno halogeniranje alkenov z reakcijskim sistemom I2/HCl/NaNO2/O2, ki temelji na aktivaciji I2 z in-situ generiranjem jodirne zvrsti HICl2 – reaktivnega jodovega(I) reagenta, kar predstavlja alternativno možnost za atomsko ekonomično in milo jodiranje organskih spojin. Uporabnost aerobnega sistema je bila podrobno raziskana na predstavnikih štirih družin alkenov, in sicer: stirenu, ciklooktenu, 1-oktenu in trans 3-heksenu. Pregledne reakcije in optimizacije potrjujejo, da jodokloriranje alkenov s HICl2 poteka po večini efektivno in selektivno. Iz dobljenega podatka o regioselektivnosti pa je za dodatek moč sklepati, da se jod v postopku elektrofilne adicije uvede kot elektrofil I+. Glavna stranska reakcija je vezava topila 2,2,2-trifluoroetanola kot nukleofila na jodonijev intermediat ter vezava vode kot nukleofila. Posebnost je transformacija 1-oktena, kjer nastaneta oba regioizomera v enakem deležu, kar je lastnost terminalnih alkenov. Za konec sem primerjal še dva sintezna pristopa. Dvostopenjska adicija s predhodno generiranim HICl2 poteka na ciklooktenu v acetonitrilu selektivneje, kot enostopenjska in-situ metoda, kjer se HICl2 tvori kar v prisotnosti alkena. To dejstvo ne drži za stiren, kjer reakcija poteka bolje na enostopenjski način. Za razliko pa poteka jodokloriranje 1-oktena in trans 3-heksena v enakih deležih ne glede na sintezni pristop. One of the preferences of modern organic synthesis is to replace conventional halogenation methods with more acceptable approaches. The main research goal within this thesis was therefore to investigate aerobic iodohalogenation of alkenes with I2/HCl/NaNO2/O2 reaction system which is based on the activation of I2 by in-situ synthesis of the reactive iodine(I) species HICl2. The method consequently represents an alternative option for atomic economical and mild iodination of organic compounds. In my research, I have investigated the application of the aerobic reaction system on four types of alkenes, namely: styrene, cyclooctene, 1-octene and trans 3-hexene. In general, reviews and final optimizations proved that iodochlorination of alkenes with HICl2 is successful and mostly selective choice. From regioselectivity point of view, it can be firmly concluded that iodine in the electrophilic addition is introduced to alkene as an electrophile I+. The main side reaction was found to be the incorporation of solvent 2,2,2-trifluoroethanol as nucleophile to iodonium intermediate and incorporation of water as nucleophile. Contrary to other alkenes, in the case of 1-octene, equimolar formation of both regioisomers is preferred, which is typical for terminal alkenes. What is more, I have also compared two types of synthesis. It has been proved that two-step iodochlorination of cyclooctene with pre-generation of HICl2 leads to more selective approach than one-step in-situ method, where HICl2 is formed in the presence of alkene. In the case of styrene one-step synthesis is more efficient. Contrary, iodochlorination of 1-octene and trans 3-hexene progresses equally successful when using either one- or two-step method. halogeniranje jodokloriranje alkenov jodov(I) reagent nitroksilni radikali aerobna oksidacija halogenation iodochlorination of alkenes iodine(I) reagent nitroxyl radicals aerobic oxidation true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2019-09-09 12:10:08 2019-09-09 12:10:12 2022-08-21 03:45:02 0000-00-00 00:00:00 2019 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 6164 1538409667 Kravos_Aleksander_-_Aerobno_jodohalogeniranje_alkenov_katalizirano_z_dusikovimi_oksidi.pdf Kravos_Aleksander_-_Aerobno_jodohalogeniranje_alkenov_katalizirano_z_dusikovimi_oksidi.pdf 1 5A19DC00671D841BE18073270C26D19A c12d4eb34234d0986c1e24abe8f78260dca179a18ba8b96c3358145d9c2c3f2c fa7c7492-a1b6-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=121471 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0