Facile one-pot synthesis and in silico study of new heterocyclic scaffolds with 4-pyridyl moiety: Mechanistic insights and X-ray crystallographic elucidation.

4-Acetylpyridine 1 and malononitrile 2 were allowed to react in a 3MCRs with dimedone 3a or cyclohexa-1,3-dione 3b under reflux to afford 4-methyl-4-(pyridin-4-yl)-5,6,7,8-tetrahydro-4H-chromene derivatives 4a,b respectively. The mechanism of the reaction has been studied and the structures elucidated by analytical, spectral as well as X-ray crystallographic data. Heterocyclic compounds find widespread application in pharmaceutical and agrochemical products. Docking analyses were performed on the synthesized compounds to assess their binding modes with various amino acids of the target protein tubulin (PDB Code - 1SA0). The results indicated promising binding scores for compounds 4a and 4b, suggesting a strong affinity for the tubulin binding site. Finally, ADMET for the synthesized compounds 4a, 4b, 5, 8a and 8b were carried out. The drug likeness and pharmacokinetic properties of the prepared compounds were also evaluated. Notably, all of the novel compounds adhered to Lipinski's rule (Ro5) without any violations.

(2R,4S,5S)-5-Meth-oxy-4-methyl-3-oxohept-6-en-2-yl benzoate.

The title compound, C16H20O4, was synthesized in the course of the total synthesis of fusaequisin A in order to verify and confirm the configurations of the stereogenic centers and to exclude the possibility of epimerization during the methyl-ation process. The crystal structure of the title compound at 100 K has ortho-rhom-bic (P212121) symmetry. The absolute configuration was determined by anomalous dispersion and agrees with the configuration of the allylic alcohol used in the synthesis.

Photochemical Approach to the Cyclohepta[b]indole Scaffold by Annulative Two-Carbon Ring-Expansion.

We report on the implementation of the concept of a photochemically elicited two-carbon homologation of a π-donor-π-acceptor substituted chromophore by triple-bond insertion. Implementing a phenyl connector between the slide-in module and the chromophore enabled the synthesis of cylohepta[b]indole-type building blocks by a metal-free annulative one-pot two-carbon ring expansion of the five-membered chromophore. Post-irradiative structural elaboration provided founding members of the indolo[2,3-d]tropone family of compounds. Control experiments in combination with computational chemistry on this multibond reorganization process founded the basis for a mechanistic hypothesis.