Julia Stephanidou-Stephanatou

Bio: Julia Stephanidou-Stephanatou is an academic researcher from Aristotle University of Thessaloniki. The author has contributed to research in topics: Chromone & Cycloaddition. The author has an hindex of 16, co-authored 134 publications receiving 1087 citations.

1,5-Benzoxazepines vs 1,5-benzodiazepines. One-pot microwave-assisted synthesis and evaluation for antioxidant activity and lipid peroxidation inhibition

Abstract: Amino-1,5-benzoxazepines 2 and 5 and hydroxyl-1,5-benzodiazepines 3 and 6 have been synthesized in one-pot solvent-free conditions from 2,3-diaminophenol and ketones through microwave assisted acid catalysis, the benzoxazepine/benzodiazepine ratio depending on the R1 and R3 aryl substituents. The otherwise inaccessible and unknown 2,2-dimethyl-4-aryl-1,5-benzodiazepines 8 were also prepared in an analogous manner. The reaction mechanism was investigated by means of DFT calculations. Structural assignments of the new compounds as well as complete assignment of 1H and 13C NMR signals have been unambiguously achieved on the basis of the analysis of their 1H and 13C NMR (1D and 2D), IR, MS, and elemental analysis data, whereas the presence of an amino group in 5 and of a hydroxyl in 6 was confirmed by derivatization. Compounds 2, 3, 5f, 6a, 6c, 6d, 6f, 6h, 8c, and 12 were evaluated as antioxidants and lipid peroxidation inhibitors in vitro. Compound 6f was also evaluated as anti-inflammatory agent in vivo. Co...

Dimethyl Acetylenedicarboxylate: A Versatile Tool in Organic Synthesis

Abstract: This review presents the recent progress in the chemistry of dimethyl acetylenedicarboxylate (DMAD). The interest in and applications of this powerful reagent with more than 135 years of history have greatly increased in the last 10 years, further proving its versatility. Undoubtedly, DMAD can be a multi-tool in the quest of molecular complexity and diversity. The extreme structural diversity of the products described in this review illustrates the powerful potential of DMAD as a building block in organic synthesis. 1 Introduction 2 Michael Reactions 2.1 Sulfur as Nucleophile 2.2 Nitrogen as Nucleophile 2.3 Oxygen as Nucleophile 2.4 Addition to Carbon–Carbon Double Bonds 3 Cycloaddition Reactions 3.1 Diels–Alder Reactions ([4+2] Cycloadditions) 3.2 1,3-Dipolar Reactions ([3+2] Cycloadditions) 3.3 [2+2] Cycloadditions 3.4 [8+2] Cycloadditions 4 DMAD and the Generation of Zwitterions; Multicomponent Reactions (MCRs) 4.1 Phosphines and Derivatives 4.2 Amines 4.3 Isocyanides 4.4 Carbenes 4.5 Miscellaneous Reactions 5 Conclusion

One-pot synthesis of functionalized spirobenzofuranones via MCR involving 3-cyanochromones.

Abstract: Another aspect concerning chromone chemistry leading to the one-pot synthesis of functionalized novel spirobenzofuranones has been described. The synthesis involves reaction of the zwitterionic intermediates formed by the 1:1 interaction between isocyanides and acetylenecarboxylates with 3-cyanochromones, whereupon through an unexpected and unprecedented reaction of the chromone moiety the isolated benzofuranones are formed. The regioselectivity of the reaction was investigated by DFT calculations. The geometries of the intermediates, transition structures, and intermediate products, leading to the final products, were optimized using the B3LYP functional with the 6-31G(d) basis set. The structures of the products were elucidated by 1D and 2D NMR experiments. Full assignment of all (1)H and (13)C NMR chemical shifts has been achieved. A plausible mechanistic rationale is proposed.

Ionic liquids in heterocyclic synthesis.

Abstract: 2.5. Ionic Liquids Presented in This Review 2020 3. Cyclocondensation Reactions 2020 4. Synthesis of Three-Membered Heterocycles 2022 4.1. Aziridines 2022 5. Synthesis of Five-Membered Heterocycles 2022 5.1. Pyrroles 2022 5.2. Furans 2022 5.3. Thiophenes 2023 5.4. Pyrazoles 2024 5.5. Imidazoles 2025 5.6. Isoxazoles 2027 5.7. Oxazoles, Oxazolines, and Oxazolidinones 2027 5.8. Thiazoles and Thiazolidinones 2028 6. Synthesis of Six-Membered Heterocycles 2030 6.1. Pyridines 2030 6.2. Quinolines 2031 6.3. Acridines 2033 6.4. Pyrans 2033 6.5. Flavones 2035 6.6. Pyrimidines and Pyrimidinones 2035 6.7. Quinazolines 2037 6.8. -Carbolines 2038 6.9. Dioxanes 2039 6.10. Oxazines 2039 6.11. Benzothiazines 2040 6.12. Triazines 2040 7. Synthesis of Seven-Membered Heterocycles: Diazepines 2041

Chromone: A Valid Scaffold in Medicinal Chemistry

Abstract: This work was supported by the Foundation for Science and Technology (FCT), Portugal (projects PTDC/QUI-QUI/113687/2009 and PEst-C/QUI/UI0081/2013). A.G. (SFRH/BD/43531/2008) and M.J.M. (SFRH/BD/61262/2009) thank FCT for grants.

Tetrazoles via Multicomponent Reactions.

Abstract: Tetrazole derivatives are a prime class of heterocycles, very important to medicinal chemistry and drug design due to not only their bioisosterism to carboxylic acid and amide moieties but also to their metabolic stability and other beneficial physicochemical properties. Although more than 20 FDA-approved drugs contain 1 H- or 2 H-tetrazole substituents, their exact binding mode, structural biology, 3D conformations, and in general their chemical behavior is not fully understood. Importantly, multicomponent reaction (MCR) chemistry offers convergent access to multiple tetrazole scaffolds providing the three important elements of novelty, diversity, and complexity, yet MCR pathways to tetrazoles are far from completely explored. Here, we review the use of multicomponent reactions for the preparation of substituted tetrazole derivatives. We highlight specific applications and general trends holding therein and discuss synthetic approaches and their value by analyzing scope and limitations, and also enlighten their receptor binding mode. Finally, we estimated the prospects of further research in this field.