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Optimiziral sem organokatalizirano sulfa-Michaelovo/aldolno kaskadno reakcijo med benzilidenskim derivatom pirolona in 2-merkaptoacetaldehidom. Pri optimalnih reakcijskih pogojih sem iz heteroarilidenskih derivatov pirolin-4-onov pripravil knjižnico desetih spirocikličnih spojin. Reakcije so v večini primerov potekle izredno stereoselektivno (do >99% ee, dr 96:4), produkti so bili izolirani s solidnimi izkoristki (32–84%). Produkti vsebujejo spirociklične, pirolonske in tetrahidrotiofenske motive, ki pogosto izražajo biološko aktivnost. Iz aminokislinskih gradnikov sem sintetiziral pirolin-4-onom sorodno tetramsko kislino in njen benzilidenski derivat. Slednjega sem uporabil v dveh organokataliziranih pretvorbah z 1,4-ditian-2,5-diolom in izoliral spirociklični produkt. Uporaba dveh različnih katalizatorjev je privedla do nastanka popolnoma različnih diastereomerov. Optimization of organocatalyzed sulfa-Michael/aldol cascade reaction of benzylidene-pyrrolone derivative using 2-mercaptoacetaldehyde was carried out. Under optimized reaction conditions, a library of 10 spirocyclic compounds was synthesized from respective heteroarylidene-pyrroline-4-ones. Reactions proved to be highly stereoselective (up to >99% ee, dr 96:4), yielding decent amounts of isolated spirocyclic compounds (32–84%). The end products contain spirocyclic, pyrrolone and tetrahidrothiophene motifs that frequently exhibit biological activity. Amino acid building blocks have been used to synthesize pyrroline-4-one related tetramic acid and its benzylidene derivative. Benzylidene-tetramic acid has been subsequently reacted with 1,4-dithiane-2,5-diol in the presence of an organocatalyst yielding a novel spirocyclic product. The application of two different organocatalysts led to the formation of two different diastereomers. |
