Recent Advances in Ruthenium-Catalyzed Carbene/Alkyne Metathesis (CAM) Transformations

NOTICE: This is the peer reviewed version of the following article: Padín, D., Varela, J. A., Saá, C. (2020). Recent Advances in Ruthenium-Catalyzed Carbene/Alkyne Metathesis (CAM) Transformations. Synlett, 31, 12, 1147-1157. [doi: 10.1055/s-0039-1690861]. This article may be used for non-commercial purposes in accordance with Thieme Terms and Conditions for self-archivingCarbene intermediates have shown versatile applications in modern synthetic chemistry. Catalytic ruthenium carbene/alkyne metathesis (CAM) with readily available substrates renders an efficient procedure for the in situ generation of ruthenium vinyl carbene intermediates. Here, recent advances in synthetic applications of ruthenium-catalyzed carbene/alkyne metathesis (CAM) are highlighted.This work has received financial support from MINECO (project CTQ2017-87939R and ORFEO-CINQA network RED2018-102387-T), the Xunta de Galicia (project ED431C 2018/04 and Centro singular de investigación de Galicia accreditation 2019-2022, ED431G 2019/03) and the European Union (European Regional Development Fund – ERDF). D. P. thanks MEC for a predoctoral FPU fellowship (FPU15/02132)S

Tautomerism and Fragmentation of Biologically Active Hetero Atom (O, N)-Containing Acyclic and Cyclic Compounds Under Electron Ionization

In this thesis a total of 86 compounds containing the hetero atoms oxygen and nitrogen were studied under electron ionization mass spectrometry (EIMS). These compounds are biologically active and were synthesized by various research groups. The main attention of this study was paid on the fragmentations related to different tautomeric forms of 2- phenacylpyridines, 2-phenacylquinolines, 8-aryl-3,4-dioxo-2H,8H-6,7-dihydroimidazo- [2,1-c][1,2,4]triazines and aryl- and benzyl-substituted 2,3-dihydroimidazo[1,2-a]pyrimidine-5,7-(1H,6H)-diones. Also regio/stereospecific effects on fragmentations of pyrrolo- and isoindoloquinazolinones and naphthoxazine, naphthpyrrolo-oxazinone and naphthoxazino-benzoxazine derivatives were screened. Results were compared with NMR data, when available. The first part of thesis consists of theory and literature review of different types of tautomerism and fragmentation mechanisms in EIMS. The effects of tautomerism in biological systems are also briefly reviewed. In the second part of the thesis the own results of the author, based on six publications,are discussed. For 2-phenacylpyridines and 2-phenacylquinolines the correlation of different Hammett substituent constants to the relative abundances (RA) or total ion currents (% TIC) of selected ions were investigated. Although it was not possible to assign most of the ions formed unambiguously to the different tautomers, the linear fits of their RAs and % TICs can be related to changing contributions of different tautomeric forms. For dioxoimidazotriazines and imidazopyrimidinediones the effects of substituents were rather weak. The fragmentations were also found useful for obtaining structural information. Some stereoisomeric pairs of pyrrolo- and isoindoloquinazolines and regiomeric pairs of naphtoxazine derivatives showed clear differences in thir mass spectra. Some mechanisms are suggested for their fragmentations.Siirretty Doriast

Synthesis and evaluation of cerebroprotective activity of novel 6,7-dimethoxyquinazolin-4(3H)-one derivatives containing residues of amino acids and dipeptides

Neurodegenerative processes of the central nervous system are an important socially significant problem of modern society. They cause many diseases, such as Alzheimer's disease and cerebral ischemia, which significantly reduce the quality of human life and can lead to disability or death. The aim of this study was to synthesize novel 6,7-dimethoxyquinazolin-4(3H)-one derivatives with the remains of neuroactive amino acids and dipeptides in order to investigate their cerebroprotective properties. As a result of the study, 13 novel 6,7-dimetho-xyquinazolin-4(3H)-one derivatives were synthesized. Cerebral ischemia in rats was reproduced by irreversible right-sided occlusion of the middle cerebral artery using the Tamura method, and the area of brain necrosis was evaluated. Cognitive functions were evaluated in the Y-maze test. Among the studied quinazolinone derivatives, compounds 3i, 3j and 3k have the most pronounced cerebrotropic activity, which is not inferior to ethylmethylhydroxypyridine succinate in terms of pharmacological activity, making them promising objects for further research

Preparation, Antimicrobial Evaluation and Molecular docking of New 2,3-Substituted [1,3] Benzooxazin-4-one derivatives

New 2, 3-substituted benzooxazin-4-one derivatives were prepared by means of a altered step by step proceedings in which Schiff bases were substituted with salicylic acid for a ring forming reaction. The compositions of the synthesized compounds were certain via methods spectrometry as elemental analysis, FT-IR, 13C-NMR & 1H-NMR spectral analysis. The bio-activities for the prepared compounds in-vitro as antibacterial and antifungal were estimated as opposed to two races of gram-positive & two races of gram-negative bacteria as parallel to Cefotaxime sodium as regular drug and assessed versus two types of fungi. The prepared compounds were got to have antimicrobial activities spreading from middling to perfect against of the bacteria strains with good percentage mycelial growth inhibition activity against fungi. Molecular docking displays the critical part while effect of variety of substituents on biological activity while mark the disadvantageous constitutional parameters in drawing medication: A different substitution does ensure additional efficiency in bioactivity