19 research outputs found
Azidoperfluoroalkany: Syntéza a Aplikace
ZavedenĂ trifluormethylovĂ© a perfluoralkylovĂ© skupiny do organickĂ˝ch molekul pĹ™edstavuje jedno z hlavnĂch tĂ©mat syntetickĂ© organofluorovĂ© chemie. Existuje Ĺ™ada metod pro zavedenĂ CF3 skupiny na atom uhlĂku, kyslĂku a sĂry. Naopak metody pro syntĂ©zu N-trifluor-methylovanĂ˝ch a N-perfluoralkylovanĂ˝ch slouÄŤenin jsou velmi omezenĂ© a vĂ˝voj novĂ˝ch pĹ™ĂstupĹŻ k jejich syntĂ©ze je vysoce žádanĂ˝. Nedostatek tÄ›chto slouÄŤenin nás vedl k vĂ˝voji ÄŤinidel schopnĂ˝ch pĹ™enosu perfluoralkylovĂ© skupiny na atom dusĂku, kde jsme jako vhodná ÄŤinidla zvolili azidoperfluoralkany. Tato práce se zabĂ˝vá syntĂ©zou a aplikacĂ perfluoralkylazidĹŻ. Prvnà část popisuje pĹ™Ăpravu azidoperfluoralkanĹŻ. Po aktivaci fluoridem cesnĂ˝m mĹŻĹľe TMSCF3 pĹ™enĂ©st trifluormethylovou skupinu na elektrofilnĂ azid za vzniku žádanĂ©ho azidotrifluormethanu. Azidoperfluoralkany s delšĂm uhlĂkatĂ˝m Ĺ™etÄ›zcem byly pĹ™ipraveny podobnĂ˝m zpĹŻsobem vycházejĂcĂm z pĹ™ĂslušnĂ©ho organosilanu. RozdĂlnĂ˝ syntetickĂ˝ pĹ™Ăstup byl pouĹľit pro pĹ™Ăpravu azidoperfluorethanu, kde byl pĹ™i reakci pentafluorethanu s n BuLi generován perfluorethylovĂ˝ anion, k nÄ›muĹľ byl následnÄ› pĹ™idán tosylazid. FluorovanĂ© azidy byly izolovány pomocĂ destilace s vhodnĂ˝m rozpouštÄ›dlem. Druhá část se zabĂ˝vá syntetickĂ˝m potenciálem azidoperfluoralkanĹŻ. Tyto azidy vykazovaly velkou reaktivitu v azido-alkynovĂ˝ch...The incorporation of the trifluoromethyl and perfluoroalkyl motifs into organic compounds has been a hot topic in synthetic organofluorine chemistry. There is a plethora of methods for the introduction of the CF3 moiety at carbon, oxygen and sulfur centers. In sharp contrast, methods for synthesizing N-trifluoromethyl and N-perfluoroalkyl compounds are very limited and new approaches are highly sought-after. The scarcity of these compounds prompted us to develop reagents capable of transferring the perfluoroalkyl unit to nitrogen atom. To fulfil this purpose, we have regarded azidoperfluoroalkanes as ideal reagents, therefore, this thesis is concerned with the synthesis and applications of these azides. The first part describes the preparation of azidoperfluoroalkanes. Upon activation by cesium fluoride, TMSCF3 transfers the trifluoromethyl group to an electrophilic azide to produce the desired azidotrifluoromethane. Longer carbon chain azidoperfluoroalkanes were prepared in a similar way, starting from the corresponding organosilane. A different synthetic strategy was applied for the preparation of azidopentafluoroethane where the perfluoroalkyl anion was generated from pentafluoroethane with n BuLi, followed by the addition of tosyl azide. The isolation of these fluorinated azides was...Department of Organic ChemistryKatedra organickĂ© chemieFaculty of SciencePĹ™ĂrodovÄ›decká fakult
Azidoperfluoroalkanes: Synthesis and Application
The incorporation of the trifluoromethyl and perfluoroalkyl motifs into organic compounds has been a hot topic in synthetic organofluorine chemistry. There is a plethora of methods for the introduction of the CF3 moiety at carbon, oxygen and sulfur centers. In sharp contrast, methods for synthesizing N-trifluoromethyl and N-perfluoroalkyl compounds are very limited and new approaches are highly sought-after. The scarcity of these compounds prompted us to develop reagents capable of transferring the perfluoroalkyl unit to nitrogen atom. To fulfil this purpose, we have regarded azidoperfluoroalkanes as ideal reagents, therefore, this thesis is concerned with the synthesis and applications of these azides. The first part describes the preparation of azidoperfluoroalkanes. Upon activation by cesium fluoride, TMSCF3 transfers the trifluoromethyl group to an electrophilic azide to produce the desired azidotrifluoromethane. Longer carbon chain azidoperfluoroalkanes were prepared in a similar way, starting from the corresponding organosilane. A different synthetic strategy was applied for the preparation of azidopentafluoroethane where the perfluoroalkyl anion was generated from pentafluoroethane with n BuLi, followed by the addition of tosyl azide. The isolation of these fluorinated azides was..