Uporaba tetramskih kislin kot izhodnih substratov v organokataliziranih pretvorbah

Hozjan, Mišel (author), Grošelj, Uroš (mentor)

Izvedel sem organokatalizirano asimetrično reakcijo Michaelove adicije iz N-Boc-glicina pridobljene tetramske kisline na različne derivate trans-β-nitrostirena. Produkte adicije sem alkiliral z raznimi alkilirnimi sredstvi, predvsem pa z benzil bromidom. Reakcije so potekle enantioselektivno (% ee od 81 do 94). Uspešno sem asimetrično adiral tudi iz N-Boc-glicilglicilglicina pridobljeno tetramsko kislino na trans-β-nitrostiren. Po alkiliranju z benzil bromidom sem produktu določil 59 % ee. Izbranim produktom sem odstranil Boc zaščitno skupino in jih poskusil kristalizirati z namenom pridobitve monokristalov. S pomočjo elektrofilnega fluoriranja sem vnesel fluor v derivat tetramske kisline. Tvoril sem amid s pripravljenim karboksilnim derivatom tetramske kisline s pomočjo in situ aktivacije in dodatkom aminokisline. Poskusil sem tudi asimetrično adirati tetramsko kislino na benzilidenmalononitril v prisotnosti organokatalizatorja, vendar mi je uspelo pridobiti le racemni produkt.

• Language: Slovenian
• Keywords: organokataliza, bifunkcionalna kataliza, tetramska kislina, trans-β-nitrostiren
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2021
• PID: 20.500.12556/RUL-129647
• COBISS.SI-ID: 79683843
• Publication date in RUL: 06.09.2021

Secondary language

• Language: English
• Title: Use of tetramic acids as starting substrates in organocatalyzed conversions

Abstract

I carried out organocatalysed asymmetric Michael addition involving N-Boc derived tetramic acid and different trans-β-nitrostyrene derivatives. The products of addition were alkylated with different alkylating agents, but mostly with benzyl bromide. Reactions were enantioselective (% ee from 81 to 94). I also successfully asimmetrically added from N-Boc-glycylglycylglycine prepared tetramic acid to trans-β-nitrostyrene. After alkylating the product with benzyl bromide, the enantioselectivity was determined to be 59 %. For selected products, I removed the Boc protecting group and tried crystallising them in order to obtain monocrystals. With the help of electrophilic fluorination I introduced fluorine into a derivate of tetramic acid. I synthesized an amide from the carboxylic acid derivate of tetramic acid using in situ activation and addition of an amino acid. I also tried to asymmetrically add tetramic acid to benzylidene-malononitrile catalyzed by organocatalyst, but I only managed to prepare a racemic product.

• Keywords: organocatalysis, bifunctional catalysis, tetramic acid, trans-β-nitrostyrene