One-Pot, Multi-Component Green Microwave-Assisted Synthesis of Bridgehead Bicyclo[4.4.0]boron Heterocycles and DNA Affinity Studies

• Published in: International journal of molecular sciences Vol. 25; no. 18; p. 9842
• Main Authors: Paisidis, Polinikis, Kokotou, Maroula G, Kotali, Antigoni, Psomas, George, Fylaktakidou, Konstantina C
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.09.2024; MDPI
• Subjects: Aldehydes - chemistry; Amino acids; Animals; Boron; boron heterocycles; Boronic Acids - chemistry; Bridged Bicyclo Compounds - chemistry; Cattle; Chemistry Techniques, Synthetic; DNA; DNA - chemistry; DNA interaction; Genetic research; Green Chemistry Technology - methods; green synthesis; Heterocyclic Compounds - chemical synthesis; Heterocyclic Compounds - chemistry; microwave irradiation; Microwaves; Molecular Structure; multi-component reaction; one-pot reaction; ortho-Aminobenzoates - chemistry; Solvents; Greece; Germany; multi-component reaction; microwave irradiation; one-pot reaction; green synthesis; DNA interaction; boron heterocycles
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms25189842

Anthranilic acids, salicylaldehydes and arylboronic acids reacted in EtOH/H O (1/3) at 150 °C under microwave irradiation for 1 h to give, in excellent yields and purity, twenty-three bridgehead bicyclo[4.4.0]boron heterocycles via one-pot, three-component green synthesis. The scope and the limitations of the reactions are discussed in terms of the substitution of ten different anthranilic acids, three salicylaldehydes and three arylboronic acids. The replacement of salicylaldehyde with -hydroxyacetophenone demanded a lipophilic solvent for the reaction to occur. Eight novel derivatives were isolated following crystallization in a toluene-containing mixture that included molecular sieves. The above one-pot, three-component reactions were completed under microwave irradiation at 180 °C within 1.5 h, thus avoiding the conventional prolonged heating reaction times and the use of a Dean-Stark apparatus. All derivatives were studied for their affinity to calf thymus DNA using proper techniques like viscosity and UV-vis spectroscopy, where DNA-binding constants were found in the range 2.83 × 10 -8.41 × 10 M . Ethidium bromide replacement studies using fluorescence spectroscopy indicated Stern-Volmer constants between 1.49 × 10 and 5.36 × 10 M , whereas the corresponding quenching constants were calculated to be between 6.46 × 10 and 2.33 × 10 M s . All the above initial experiments show that these compounds may have possible medical applications for DNA-related diseases.