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Figure 8

Publications

Publications
Principal original articles, reviews, chapters and books published by our group
2022

2022

New insights about structure/optical waveguide behavior relationships in linear bisethynylbenzenes  

C. Tardío, J. Álvarez-Conde, I. Torres-Moya, A. M. Rodríguez, A. de la Hoz, J. Cabanillas-González, P. Prieto

J. Mater. Chem. C Manuscript ID: TC-ART-01-2022-000173.R1

In order to establish a relationship between the structure and the optical waveguiding behavior, two series of linear bisethynylbenzenes combining trifluoromethyl and methoxy groups in the core and external rings were synthesized. The presence of the methoxy groups in the core benzene produced, generally, amorphous supramolecular aggregates, while the presence of trifluoromethyl groups in the core benzene produced needle shape crystals. As a result of this most planar compounds showed optical waveguiding behavior as shown by photoluminescence (PL) microscopy and optical loss coefficients down to 0.54x10-3 dB μm-1 in some of them, revealing optical waveguides assets. X-ray diffraction studies performed to establish a first approximation to the structure/optical property relationships confirming that the presence of channels in the crystal structure is concomitant with optical waveguiding behavior. This feature constitutes a relevant parameter to be taken into account to understand light propagation in these structure.

DOI: 10.1039/x0xx00000x

Benzotriazole-based multidonor-acceptor systems as attractive two-photon absorption dye platforms

S. Sierra, M. V. Gomez, A. I. Jiménez, A. Pop, C. Silvestru, M. L. Marín, F. Boscá, G. Sastre, E. Gómez-Bengoa, E. P. Urriolabeitia.

Dyes Pigments 2022, 200, 110149

Pyrazine-decorated benzotriazole cores allow the orthogonal combination of two dipolar systems within a single molecule. A series of this type of derivatives was synthesized and their photophysical features were studied. The properties of these compounds showed remarkable differences in function depending on the substitution in the pyrazine ring of the benzotriazole core. Furthermore, the two-photon absorption property (2PA) was studied to determine the structure-properties relationship for the reported compounds. The best dye achieved a crosssection of 1532 GM, which was higher than values previously obtained for similar D-π-A-π-D benzotriazole derivatives. TD-DFT calculations, which supported the experimental observations, indicating the interaction between the two dipolar systems was responsible for enhancing the 2 PA properties and favoring bathochromic
shifts.

https://doi.org/10.1016/j.dyepig.2022.110149

Stereoselective, Ruthenium-Photocatalyzed Synthesis of 1,2- Diaminotruxinic Bis-amino Acids from 4‑Arylidene-5(4H)‑oxazolones

S. Sierra, M. V. Gomez, A. I. Jiménez, A. Pop, C. Silvestru, M. L. Marín, F. Boscá, G. Sastre, E. Gómez-Bengoa, E. P. Urriolabeitia 

J. Org. Chem. 2022

 

The irradiation of (Z)-2-phenyl-4-aryliden-5(4H)-oxazolones 1 in deoxygenated CH2Cl2 at 25 °C with blue light (465 nm) in the presence of [Ru(bpy)3](BF4)2 (5% mole ratio) as a triplet photocatalyst promotes the [2+2] photocycloaddition of the C═C bonds of the 4-arylidene moiety, thus allowing the completely regio- and stereoselective formation of cyclobutane-bis(oxazolone)s 2 as single stereoisomers. Cyclobutanes 2 have been unambiguously characterized as the μ-isomers and contain two E-oxazolones coupled in an anti-head-to-head form. The use of continuous-flow techniques in microreactors allows the synthesis of cyclobutanes 2 in only 60 min, compared with the 24–48 h required in batch mode. Ring opening of the oxazolone heterocycle in 2 with a base affords the corresponding 1,2-diaminotruxinic bis-amino esters 3, which are also obtained selectively as μ-isomers. The ruthenium complex behaves as a triplet photocatalyst, generating the reactive excited state of the oxazolone via an energy-transfer process. This reactive excited state has been characterized as a triplet diradical 3(E/Z)-1* by laser flash photolysis (transient absorption spectroscopy). This technique also shows that this excited state is the same when starting from either (Z)- or (E)-oxazolones. Density functional theory calculations show that the first step of the [2+2] cycloaddition between 3(E/Z)-1* and (Z)-1 is formation of the C(H)–C(H) bond and that (Z) to (E) isomerization takes place at the 1,4-diradical thus formed.

 

DOI: 10.1021/acs.joc.1c03092

 

Flow Chemistry in Drug Discovery

This book reviews the challenges and opportunities posed by flow chemistry in drug discovery, and offers a handy reference tool for medicinal chemists interested in the synthesis of biologically active compounds.

Prepared by expert contributors, the respective chapters cover not only fundamental methodologies and reactions, such as the application of catalysis, especially biocatalysis and organocatalysis; and non-conventional activation techniques, from photochemistry to electrochemistry; but also the development of new process windows, processes and reactions in drug synthesis. Particular attention is given to automatization and library synthesis, which are of great importance in the pharmaceutical industry. Readers will also find coverage on selected topics of general interest, such as how flow chemistry is contributing to drug discovery R&D in developing countries, and the green character of this enabling technology, for example in the production of raw materials for the pharmaceutical industry from waste.

Given its scope, the book appeals to medicinal chemistry researchers working in academia and industry alike, as well as professionals involved in scale-up and drug development.

 

Green Aspects of Flow Chemistry for Drug Discovery

 In: . Topics in Medicinal Chemistry. pp 23-70. Springer, Berlin, Heidelberg. 2022