A little tribute to (THIO)UREAS. Improving their organocatalytic activity…

Hydrogen bonding and Internal or External Lewis or Brønsted Acid Assisted (Thio)urea Catalysts, Gimeno, M. C.; Herrera, R. P. Eur. J. Org. Chem. 10.1002/ejoc.201901344

Abstract. The obtainment of more active organocatalysts has promoted the search for new modes of activation and new organocatalytic systems. Inspired on the mode of activation of enzymes, organocatalysis has recently focused on the challenge to create an enzyme-like ‘active site’ giving access to hydrogen bond donors (HBDs) with enhanced activity. Therefore, the assembly of catalytic species, connected through multiple weak inter- or intramolecular interactions, is a young and emerging topic of research which could become in the future a powerful tool for asymmetric catalysis. In the area of (thio)ureas, different alternatives such as internal hydrogen bonds or the use of an internal or an external Lewis or Brønsted acid assisted catalysts have been developed. The pivotal publications recently reported covering this family of organocatalysts are proof of this importance. This review treats to illustrate these important and scarce examples and to show a plausible mode of activation for each one.

Keywords. Activation, Brønsted acid, Lewis acid, Organocatalyst, (thio)urea

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The results of a new collaboration with University of Gabes

Synthesis, structural determination and catalytic study of a new 2-D chloro-substituted zinc phosphate, (C8N2H20)[ZnCl(PO3(OH))]2, Rayes, A.; Herrera, R. P.; Moncer, M.; Ara, I.; Calestani, G.; Ayed, B.; Mezzadri, F. J. Mol. Struct. 2019, https://doi.org/10.1016/j.molstruc.2019.127216

Abstract. A novel chloro-substituted zinc-phosphate, (C8N2H20)[ZnCl(PO3(OH)]2, has been synthesized by a slow evaporation method in the presence of 1,3-cyclohexanebis- (methylamine), which acts as a template. The structure consists of vertex linked ZnO3Cl and PO3(OH) tetrahedral, assembled into corrugated porous layers [ZnCl(PO3(OH))2] with (4.82) topology. The optical properties were also investigated using Diffuse Reflecting Spectroscopy (DRS), showing that the title compound has semiconducting properties. In addition, the catalytic activity of (C8N2H20)[ZnCl(PO3(OH))]2 has been tested in the acetalisation reaction of aldehydes. The title compound displayed a high catalytic activity with practically total conversion in many examples using MeOD as solvent and as the sole source of acetalisation. More importantly, the reaction crudes are very clean and only the preferred products are found in the NMR spectra.


Zinc-phosphate, Open framework structure, Chloride-substitution, X-ray diffraction, Spectroscopic techniques, Catalytic activity
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Prof. Vieira from UFSCar (Brazil) with us, this week

This week (October, 22-25th), Prof. Fillipe Vieira Rocha from Federal University of São Carlos (Brasil), has visited our University invited by Prof. Gimeno.

His mission is to promote their internationalization program (UFSCar PrInt) that supports, encourages and consolidates the graduate Programs, having identified 5 priority research areas. Specially, he is actively working for Integrated Technologies for Health: from Prevention to Rehabilitation Theme, which integrated Chemistry Department.

Very interesting!



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Re-thinking ISQCH in Jaca

During few days (October, 23-25th) ISQCH members have been in Jaca (Huesca), re-thinking the institute in terms of chemistry and organization.

Raquel told us about Visualization and Internationalization, a part of about HOCA CHEMISTRY. She took us through her pasionated talks!

Raquel’s moods.

Raquel, Conchita, Fillipe, Maru (left to right).

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Wedding bells ring!

Last fridey (October, 18th), two HOCA members got married!

Congrats, Isaac and Sandra! 😉

May the CHEMISTRY be with you!



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Raquel has promoted to “Investigador Científico”!!

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Closing a period of life opens you new horizons. Good luck!

Sara and Pablo, the youngest HOCA members, did their final exams last wenesday (september, 25th) and now they are ready to get their B.Sc. Diplomes.

Organic Privileged Scaffolds with Anticancer Activity: Synthesis through Organocatalytic Procedures. Sara Gil.

Design and synthesis of chiral organocatalysts and study of their applications. Pablo Murillo.

Of course, we celebrated it together around the table.


Sara, Raquel, Maru, Isaac, Pablo and Fernando (from left to right).


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Looking for intermediates of reaction to clarify the previously established mechanism

Thiolate Bridged Gold(I) NHC Catalysts: New Approach for Catalyst Design and its Application Trapping Catalytic Intermediates, Visbal, R.; Herrera, R. P.; Gimeno, M. C. Chem. Eur. J. 2019https://doi.org/10.1002/chem.201903494

Abstract. Novel dinuclear N ‐heterocyclic gold complexes with bridging thiolate ligands have been designed to be catalytic precursors with desired properties such as stability, recyclability and the no necessity of additives. The dinuclear species [(AuNHC) 2 (µ‐SC 6 F 5 )]OTf are complexes that could slowly release the active catalytic species AuNHC + and the precursor [Au(SC 6 F 5 )(NHC)] in solution, which means that both species would maintain stable during all catalytic cycle and the pre‐catalyst could easily be recovered. These properties shown by the complexes have been taken advantage to get new insights in the gold catalyzed hydroalkoxylation of alkynes, with the aim of clarifying all the steps of the catalytic cycle, together with the characterization of intermediates and final products. Isolation and characterization of the pure final spiroketals and the thermodynamic intermediate have been achieved for the first time. Moreover, the kinetic intermediate has been also detected for the first time.

Keywords. N-Heterocyclic carbenes, gold catalysis, hydroalkoxylation reactions, reaction mechanism, cyclization reactions



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Two old friends visited us!

Last 6th September, Prof. David Díaz Díaz from the “INSTITUTE OF NATURAL PRODUCTS AND AGROBIOLOGY” – CSIC (Tenerife, Spain), visited us. We enjoyed talking about Chemistry and much more 😉

Thanks a lot for coming to Zaragoza one more time! See you next year in the island!

David Díaz Díaz and Raquel P. Herrera.


And few days later, last 10th Septembre, our former PhD student and a good friend, Juanvi (currently, a very suscesfull postdoctoral researcher at Colorado State University – Department of Chemistry, USA), was with us for a while in his quick visit to Europe.

Of course, we went to our fovourite Japanese restaurant! Ummm, delicius!

Thanks for your vistit, short but very nice! You are always nicly welcome in ZGZ!

Raquel, Juanvi, Fer and Isaac.

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Synthesis of optically active warfarin by using an aromatic amine

First aromatic amine organocatalysed activation of α,β-unsaturated ketones, Sonsona, I. G.; Marqués-López, E.; Gimeno, M. C.; Herrera, R. P. New J. Chem. 2019, 43, 12233-12240. DOI: 10.1039/c9nj02392e.

Abstract. This work provides an unprecedented example of a chiral aromatic amine used to activate α,β-unsaturated ketones in asymmetric aminocatalysis. Chiral aromatic diamine VII has been efficiently employed, as a proof of concept, in the Michael addition reaction between benzylideneacetones (1a–f) and coumarins (2a–d). The reaction gives rise to warfarin derivatives 3 with promising results using this family of catalysts for the first time. The additional studies performed supported the bifunctional mode of activation of the chiral catalyst VII and the covalent nature of the interactions between the catalyst VII and benzylideneacetones 1.

Congratulations, Isaac!


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