1,3-Diarilalkinonų ciklizacijos reakcijos susidarant izoksazolams, chromonams ir 2,3,5-tripakeistiems tiofenams

1,3-Diarylalkynones were first mentioned in literature in 1892. Since then alkynones became very valuable starting materials in organic synthesis. These substrates are versatile intermediates for five or six membered heterocycles such as, isoxazoles, chromones, thiophenes, pyrroles and others. During the past ten years our team has focused on the chemistry of C≡C triple bond. We decided to explore chemical reactivity between oxocarbenium ions and 1,3-diarylalkynones which are structurally similar to previously studied propargylic compounds. These studies led to the development of new method for C-C bond formation. Obtained substances were potentially bioactive alkoxymethyl groups containing isoxazoles and chromones. We have also found that odorless, stable, and easily synthesized carbamimidothioates can be used as building blocks for 2,3,5-trisubstituted thiophenes via Fiesselmann type cyclization between alkynones and carbamimidothioates. It was found, that the introduction of electron deficient arenes in 3rd position and electron rich arenes in 5th position of the thiophene ring not only allowed to achieve photo luminescence quantum yield up to 83% for 2-(2-benzimidazoyl) thiophenes but also enhances PLQY of the less emissive pyridine-containing thiophenes