92733-94-3Relevant academic research and scientific papers
Exploring the acidic catalytic role of differently structured deep eutectic solvents in the aza-Michael addition of amines to 2-vinylpiridine
Ballarotto, Marco,Cappellini, Federico,Del Giacco, Tiziana,Di Profio, Pietro,Germani, Raimondo,Maestri, Riccardo,Tiecco, Matteo
, (2020/08/26)
Abstract: The search for innovative and green reaction media is a prominent topic in the recent research in chemistry. Deep Eutectic Solvents (DESs) are currently gaining relevance in this field thanks to their unique properties in terms of their “greenness” as well as in terms of their catalytic properties. In this work we developed an efficient protocol for the conjugate aza-Michael addition of amines to 2-vinylpyridine using 14 differently structured acid DESs as both reaction media and catalysts, so preventing the use of other acid additives. The results are influenced by the acidity of the components of the DESs, showing the best results with weak acids in the DESs components, with isolated yields up to 86%. The aza-Michael reaction is a widely used synthetic route for the C–N bond formation in organic synthesis. In particular, the addition of amines to 2-vinylpyridine is used for the realization of pharmaceutically relevant compounds with anticancer, antiarrhythmic, and analgesic properties. Comparing the results with the ones observed in literature for the same reaction, this procedure revealed to be a convenient and efficient method for this relevant transformation. Graphic abstract: [Figure not available: see fulltext.]
Quantifying factors that influence metal ion release in photocaged complexes using ZinCast derivatives
Gwizdala, Celina,Singh, Charlene V.,Friss, Tracey R.,MacDonald, John C.,Burdette, Shawn C.
scheme or table, p. 8162 - 8174 (2012/08/08)
Two generations of nitrobenzhydrol-based photocages for Zn2+ have been prepared and characterized. The first series includes the tridentate ZinCast-1 utilizes a bis-pyridin-2-ylmethyl-aniline ligand that forms a 5,5-chelate ring upon metal binding. The related photocages ZinCast-2 with a N-[2-(pyridine-2-yl)ethyl]-N-(pyridine-2-ylmethyl)aniline (5,6-chelate ring) and ZinCast-3 with a N,N-bis[2-(pyridine-2-yl)ethyl]aniline (6,6-chelate ring) were synthesized for comparative studies. The complexes formed by the ions Cu 2+, Zn2+ and Cd2+ with three ZinCast and their photoproducts (ZinUnc) were interrogated by UV-Vis spectroscopy. The studies indicate that ZinCast-1 forms complexes of the highest stability and ZinCast-3 exhibits the most significant changes in metal affinity upon uncaging. These results suggest that the changes in nitrogen atom donor ability as well as the initial complex stability must be considered to design a photocage with the desired properties. The composite results were used to design ZinCast-4 and ZinCast-5, the second generation photocages that incorporate an additional adjacent ether ligand into the Zn2+ chelator.
