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In this work, we describe the Michael addition–cyclization reaction of 2-(2-nitrovinyl)phenol with two different reactive Michael donors, which lead to chiral benzopyran derivatives. Specifically, bifunctional amino-squaramides with one or two chiral units in the side chains were evaluated as catalysts in these transformations. Furthermore, the utility of selected green solvents as reaction media for these processes was also tested. The best result was achieved with methyl-cyclopentanone-2-carboxylate as the Michael donor in ethyl (–)-l-lactate with quinine-based amino-squaramide as catalyst (yield 72%, dr >99:1, ee 99%).

The paper is dedicated to the research output presented at the jubilee 50th edition of the international scientific conference Synthesis and Analysis of Drugs 2022 (SAL), which was organized and hosted by the Faculty of Pharmacy of Masaryk University in Brno. Since its launch in 1971, when Jozef Čižmárik from the Faculty of Pharmacy of the Comenius University in Bratislava started organizing SAL, significant progress in medicinal chemistry has been documented every year through the experimental works of researchers from different scientific institutions, both universities and academies of sciences as well as companies. We must point out long-term guest of SAL, Miroslav Protiva, co-founder of the antihistamine dosulepin and antiemetic moxastine-teoclas. As already mentioned, SAL 2022 was held at the Faculty of Pharmacy in Brno, which has been part of the University of Veterinary and Pharmaceutical Sciences for 25 years but became part of Masaryk University in 2021. Hence, the year 2022 was unique not only because of the 50th anniversary of this meeting but also for this year’s conference was the first within this institution. What topics were discussed among SAL conference participants? The meeting addressed all issues related to drug research—their design, preparation, analysis, and detection methods, as well as their biological activity studies, ADME studies, etc. The multidisciplinary character of the research, including topics on pharmaceutical technology and innovative dosage form investigation, was an additional value of the conference and its outcomes. We would like to thank the organization team and all participants for both high-quality research presentations resulting in the output of this paper and for the informal and friendly atmosphere.

The purpose of this study is to investigate the time dependent growth of silica shells on CdTe quantum dots to get their optimum thicknesses for practical applications. The core/shell structured silica-coated CdTe quantum dots (CdTe/SiO2 QDs) were synthesized by the Ströber process, which used CdTe QDs co-stabilized by mercaptopropionic acid. The coating procedure used silane primer (3-mercaptopropyltrimethoxysilane) in order to make the quantum dots (QDs) surface vitreophilic. The total size of QDs was dependent on both the time of silica shell growth in the presence of sodium silicate, and on the presence of ethanol during this growth. The size of particles was monitored during the first 72 h using two principally different methods: Dynamic Light Scattering (DLS), and Scanning Electron Microscopy (SEM). The data obtained by both methods were compared and reasons for differences discussed. Without ethanol precipitation, the silica shell thickness grew slowly and increased the nanoparticle total size from approximately 23 nm up to almost 30 nm (DLS data), and up to almost 60 nm (SEM data) in three days. During the same time period but in the presence of ethanol, the size of CdTe/SiO2 QDs increased more significantly: up to 115 nm (DLS data) and up to 83 nm (SEM data). The variances occurring between silica shell thicknesses caused by different methods of silica growth, as well as by different evaluation methods, were discussed.