Divulgación de la química en los diversos niveles educativos

Póster presentado en: VIII Jornadas de Innovación Docente de la UBU, Burgos, 5 de abril de 2016, organizadas por el Instituto de Formación e Innovación Educativa-IFIE de la Universidad de Burgo

Experimental and theoretical studies on the effect of the oxo group in 1,4-benzodiazepines

Two families of regioisomeric 1,4-benzodiazepines, 4-benzyl-3H-benzo[e][1,4]diazepin-5-ones and 4-benzoyl-4,5-dihydro-3H-benzo[e][1,4]diazepines, have been synthesized through a similar Ugi/reduction cyclization sequence. Their conformation and stability depend on the position of the tautomeric imine/enamine equilibrium present in the diazepine nucleus, which in turn depends on the relative position of the carbonyl group adjacent to the nitrogen at the 4-position in the benzodiazepine system. Moreover, the electrophilic center on the imine tautomer is essential for the antitumor activity of some benzodiazepines as a DNA binding position. The mechanism of tautomerization in the presence or absence of the oxo group has been studied computationally using DFT methods (B3LYP/6-31G** level).Ministerio de Economía y Competitividad, Spain (project CTQ2012- 31611), from Ministerio de Ciencia e Innovación, Spain and Fondo de Desarrollo Regional (project MAT2011-22781), as well as from Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (project ref. BU246A12-1 and BU327A11-2)

Complementary regioselectivity in the synthesis of iminohydantoins: remarkable effect of amide substitution on the cyclization

Complementary regioselective synthesis of iminohydantoins from isocyanoacetamides controlled by the substituent on the amide group has been described. 4-Iminohydantoins were the major products when the starting materials were N-alkyl isocyanoamides, whereas 2-iminohydantoins were the major products with N-aryl isocyanoamides.Ministerio de Ciencia e Innovación, Spain (Project CTQ2009-12631- BQU), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Projects BU023A09 and GR170)

Surface Coating by Gold Nanoparticles on Functional Polymers: On-Demand Portable Catalysts for Suzuki Reactions

We have developed new functionalized polymers capable of being easily coated by gold nanoparticles, uniformly distributed on the surface of the polymers, by simply adding a gold(III) solution in water to the polymers. The polymer-supported gold nanoparticle material was used as an efficient portable and reusable catalyst for Suzuki reactions in mixed organic−aqueous solvents.Ministerio de Economía y Competitividad, Spain, and Fondo Europeo de Desarrollo Regional (FEDER) (Projects CTQ2015-71353-R and MAT2014-54137-R), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Projects BU051U16 and BU061U16), and the European Commission, Seventh Framework Programme (Project SNIFFER FP7-SEC- 2012-312411

Synthesis of Catechol Derived Rosamine Dyes and Their Reactivity toward Biogenic Amines

Functional organic dyes play a key role in many fields, namely in biotechnology and medical diagnosis. Herein, we report two novel 2,3- and 3,4-dihydroxyphenyl substituted rosamines (3 and 4, respectively) that were successfully synthesized through a microwave-assisted protocol. The best reaction yields were obtained for rosamine 4, which also showed the most interesting photophysical properties, specially toward biogenic amines (BAs). Several amines including n- and t-butylamine, cadaverine, and putrescine cause spectral changes of 4, in UV–Vis and fluorescence spectra, which are indicative of their potential application as an effective tool to detect amines in acetonitrile solutions. In the gas phase, the probe response is more expressive for spermine and putrescine. Additionally, we found that methanolic solutions of rosamine 4 and n-butylamine undergo a pink to yellow color change over time, which has been attributed to the formation of a new compound. The latter was isolated and identified as 5 (9−aminopyronin), whose solutions exhibit a remarkable increase in fluorescence intensity together with a shift toward more energetic wavelengths. Other 9-aminopyronins 6a, 6b, 7a, and 7b were obtained from methanolic solutions of 4 with putrescine and cadaverine, demonstrating the potential of this new xanthene entity to react with primary amines.Financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e a Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the project PTDC/QUI-QOR/29426/2017. The research team would like to thank the projects UIDB/50006/2020, PTDC/QUI-QIN/28142/2017 and Grant BU263P18 (from the Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo). F. M. -S. gratefully acknowledges FCT (Portugal’s Foundation for Science and Technology) within grant DFA/BD/9136/2020. A.M.G.S. and A.L. thank FCT for the program DL 57/2016 – Norma transitória

Synthesis of water-soluble hemicoronenediimides by photocyclization of perylenediimides: Turn-on fluorescent probes in water by complexation with Cucurbit[7]uril or binding to G-quadruplex Motifs

A new series of perylene and hemicoronene diimides, obtained by visible light photocyclization, are presented, between them some remarkable examples that are soluble in only water, and give nanoparticles by selfassociation. Those compounds work as new fluorescent materials in water by complexation with cucurbit[7] uril, as well as selective G-quadruplex binding ligands with remarkable cytotoxic activity when the interaction with G4 was sufficiently strong.We acknowledge the Ministerio de Ciencia, Innovación y Universidades-FEDER (Grants PID2019-111215RB-100 and RTI2018- 102040-B-100), the Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Grants BU263P18 and BU305P18), “la Caixa” Foundation (LCF/PR/PR12/11070003) for financial support. A. R.C. thanks Secretaría General de Universidades for a FPU18/03225 Grant. This research has made use of the high-performance computing resources of the Castilla y León Supercomputing Center (SCAYLE, htt ps://www.scayle.es), financed by FEDER (Fondo Europeo de Desarrollo Regional). We thank Ms. Ma del Pilar Castroviejo-Fernández, from PCT, UBU, for assistance in AFM studies and Mr. Javier Gutierrez-Reguera from LTI, UVA, for assistance in DLS studies

Synthesis of Pyrrolidine-Fused 1,3-Dithiolane Oligomers by the Cycloaddition of Polycyclic Dithiolethiones to Maleimides and Evaluation as Mercury(II) Indicators

The scandium triflate-catalyzed cycloaddition reaction of polycyclic 1,2-dithiolethiones to maleimides is described. The reaction constitutes an easy approach to linear as well as branched oligomeric cis-fused dihydro[1,3]dithiolo[4,5-c]pyrrole-4,6-dione rings interconnected by 3,5-diylidenethiomorpholine-2,6-dithione or ylidene-6-thioxo[1,2]dithiolo[3,4-b][1,4]thiazin-3-one groups. The presence of highly colored, highly polarized push−pull α,β- unsaturated thione groups in their structures make these compounds sensitive to the presence of mercury(II) cation in organic or mixed organic/aqueous solvents.Ministerio de Economía y Competitividad, Spain (Project CTQ2012- 31611), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Project BU246A12-1), and the European Commission Seventh Framework Programme (Project SNIFFER FP7-SEC-2012-312411)

Luminescent cis-Bis(bipyridyl)ruthenium(II) Complexes with 1,2-Azolylamidino Ligands: Photophysical, Electrochemical Studies, and Photocatalytic Oxidation of Thioethers

Producción CientíficaNew 1,2-azolylamidino complexes cis-[Ru(bipy)2(NH═C(R)az*-κ2N,N)](OTf)2 (R = Me, Ph; az* = pz, indz, dmpz) are synthesized via chloride abstraction after a subsequent base-catalyzed coupling of a nitrile with the previously coordinated 1,2-azole. The synthetic procedure allows the easy obtainment of complexes having different electronic and steric 1,2-azoylamidino ligands. All of the compounds have been characterized by 1H, 13C, and 15N NMR and IR spectroscopy and by monocrystal X-ray diffraction. Photophysical studies support their phosphorescence, whereas their electrochemistry reveals reversible RuII/RuIII oxidations between +1.13 and +1.25 V (vs SCE). The complexes have been successfully used as catalysts in the photooxidation of different thioethers, the complex cis-[Ru(bipy)2(NH═C(Me)dmpz-κ2N,N)]2+ showing better catalytic performance in comparison to that of [Ru(bipy)3]2+. Moreover, the significant catalytic performance of the dimethylpyrazolylamidino complex is applied to the preparation of the drug modafinil, which is obtained using ambient oxygen as an oxidant. Finally, mechanistic assays suggest that the oxidation reaction follows a photoredox route via oxygen radical anion formation.Ministerio de Economía, Industria y Competitividad (grants PGC2018- 099470-B-I00 and RTI2018-095038-B-I00)Junta de Castilla y León (grant VA130618)Junta de Castilla y León - Fondo Social Europeo (project BU263P18

Synthesis of Fluorogenic Arylureas and Amides and Their Interaction with Amines: A Competition between Turn-on Fluorescence and Organic Radicals on the Way to a Smart Label for Fish Freshness

We describe the synthesis of fluorogenic arylureas and amides and their interaction with primary or secondary amines under air and light in organic-aqueous mixtures to give rise to a new class of persistent organic radicals, described on the basis of their electron paramagnetic resonance (EPR), as well as UV–vis, fluorescence, NMR, and quantum mechanics calculations, and their prospective use as multi-signal reporters in a smart label for fish freshness.Funded by the NATO Science for Peace and Security Programme (Grant SPS G5536), the Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Grant BU263P18), and the Ministerio de Ciencia e Innovación (Grant PID2019-111215RB-100

Self-Assembly Hydrosoluble Coronenes: A Rich Source of Supramolecular Turn-On Fluorogenic Sensing Materials in Aqueous Media

Water-soluble coronenes, that form nanoparticles by self-association, work as new fluorescent materials by complexation with cucurbit[7]uril, as well as selective turn-on fluorogenic sensors for nitroaromatic explosives with remarkable selectivity, by using only water as solvent.NATO Science for Peace and Security Programme (SPS G5536), Ministerio de Ciencia, Innovación y Universidades-FEDER (PID2019-111215RB-100 and RTI2018-102040-B-100), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (BU263P18) and “la Caixa” Foundation (LCF/PR/PR12/11070003) for financial support. A.R.C. thanks Secretaría General de Universidades (FPU18/03225)