| Abstract [eng] |
Functionalized alkynes have huge potential in the designing of new carbo- and heterocyclic scaffolds and exploring undiscovered reaction pathways for fundamental research. The aim of the present work was to investigate intramolecular cyclization or rearrangement reactions of functionalized alkynes. Three-component Kabachnik−Fields reaction was applied for the synthesis of acetylenic α-anilinomethylphosphonates. The relationship between α-aminomethylphosphonates structure and outcome of the reaction was found. Therefore, only benzene ring containing phosphonates were capable to switch their reactivity from 5-exo-dig to 6-endo-dig by using different catalyst. Whereas nonaromatic derivatives underwent 5-exo-dig cyclization processes. Contrariwise, compounds bearing pyridine or quinoline ring exclusively reacted in a 6-endo-dig manner obtaining 1,6-naphthyridine frame containing phosphonates. Metal-free, facile synthesis of oxazinones, 1,3-oxazines, 1,3-thiazines, 4,5-dihydrothiazoles and α-substituted enones from electrophile-induced cyclizations of propargylic substrates was established. New mild method of preparation of halogen, chalcogen, azide, alkoxy or aryloxy substituted pyrroles from cyclopropyl-tethered 3-alkynyl imines reaction with polar covalent bond containing compounds was developed. Powerful and straightforward double bond migration-nucleophilic addition reaction of 2-(1-alkynyl)-2-cycloalken-1-ones with amines forming (Z)-β-enaminones was found. |
