One more year, Chemistry and Young people have had an appointment; this time in the beautiful city of Toledo

Our guys attended last week (5-8 NOVEMBER 2018) the last Young Research Symposium of the Spanish Chemistry Society, celebrated in Toledo.

XV SIMPOSIO DE INVESTIGADORES JÓVENES DE LA REAL SOCIEDAD ESPAÑOLA DE QUÍMICA. REAL SOCIEDAD ESPAÑOLA DE QUÍMICA-SIGMA ALDRICH (MERCK)

They presented their work and enjoyed Toledo!!!

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Meeting of the Leonardo Network of the BBVA Foundation

Meeting of the Leonardo Network of the BBVA Foundation

Yesterday, Raquel attended to this big event celebrated in Madrid. Congratulations once again!

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Celebrating the publication of a new article!

First Organocatalytic Asymmetric Synthesis of 1-Benzamido-1,4-Dihydropyridine Derivatives,  Auria-Luna, F.; Marqués-López, E.; Herrera, R. P.  Molecules 2018, 23(10), 2692. https://doi.org/10.3390/molecules23102692. Special Issue “Stereogenic Centers

Abstract. Preliminary results concerning the first asymmetric synthesis of highly functionalized 1-benzamido-1,4-dihydropyridine derivatives via the reaction of hydrazones with alkylidenemalononitriles in the presence of β-isocupreidine catalyst are reported. The moderate, but promising, enantioselectivity observed (40–54% ee), opens the door to a new area of research for the asymmetric construction of new chiral 1,4-dihydropyridine derivatives, whose enantioselective catalytic preparation are still very limited. Moreover, the use of hydrazones for the enantioselective construction of chiral 1,4-dihydropyridines has been overlooked in the literature so far. Therefore, our research represents a pivotal example in this field which remains still unexplored.

Keywordschiral base; 1,4-dihydropyridine; enantioselective; hydrazone; organocatalysis

Congratulations Fer!!

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Raquel is in the Basque Country

She attendes to the 7ª JORNADAS DE LA RED DE CATÁLISIS ASIMÉTRICA (7J_CASI) – 2018 (4-5th October. Hondarribia – Fuenterrabía, Gipuzkoa, Spain).

No doubt about she will also enjoy the great Basque food!

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Raquel combined holidays and work last summer

Gold 2018 (15-18 July, 2018 – Paris, France)

Gold(I)-Mediated Thiourea Organocatalyst Activation: A Synergic Effect for Asymmetric Catalysis. Raquel P. Herrera, Anabel Izaga, Juan V. Alegre-Requena, M. Concepción Gimeno. (S5 O5)

 

Groupe d’Etudes en Chimie Organique 59 (26-31 August, 2018 – Cabourg, France)

New Trends in Hydrogen Bonds based Catalysts. Raquel P. Herrera.

 

She met in Cabourg an old friend, Christophe Pichon.

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Some HOCA members attend to GEQO in Zaragoza

These days (5th to 7th September 2018)  XXXVI CONGRESS OF THE ORGANOMETALLIC CHEMISTRY GROUP (GEQO) is taking place in Zaragoza.

HOCA is involved in its organization since Raquel is member of the Organaizing Committee. Is going to be a great success!!  Congratullations 😉

We present very nice and recent results from Fernando’s thesis project: Trapping enolates in pure water for the synthesis of 4H-pyran derivatives and study of their biological activity. Fernando Auria-Luna, Eugenia Marqués-López, and Raquel P. Herrera.

 

 

 

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Gold Catalyzed Multicomponent Reactions beyond A3Coupling

Gold Catalyzed Multicomponent Reactions beyond A3Coupling

Renso Visbal, Sara Graus, Raquel P. Herrera, M. Concepción Gimeno

Molecules 201823(9), 2255. https://doi.org/10.3390/molecules23092255

Abstract: The preparation of complex architectures has inspired the search for new methods and new processes in organic synthesis. Multicomponent reactions have become an interesting approach to achieve such molecular diversity and complexity. This review intends to illustrate important gold-catalyzed examples for the past ten years leading to interesting skeletons involved in biologically active compounds.

Keywords: β-alkoxyketones; butenolides; catalysis; ethers; gold; 3,4-dihydropyrimidin-2(1H)-ones; 1,4-dihydropyridines; multicomponent reactions; oxazoles; pyridines; spirocycles; thiazolo-quinolines

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Efficient Gold(I) Acyclic Diaminocarbenes for the Synthesis of Propargylamines and Indolizines

Efficient Gold(I) Acyclic Diaminocarbenes for the Synthesis of Propargylamines and Indolizines

Mélanie Aliaga-Lavrijsen, Raquel P. Herrera, M. Dolores Villacampa, and M. Concepción Gimeno

ACS Omega20183, 9805–9813.

Abstract: Mononuclear gold(I) acyclic diaminocarbenes (ADCs) were prepared by the reaction of 1,2-cyclohexanediamine with the corresponding isocyanide complexes [AuCl(CNR)] (R = Cy, tBu). The three-component coupling of aldehydes, amines, and alkynes was investigated by using these gold(I) ADC complexes. The new gold(I) metal complexes are highly efficient catalysts for the synthesis of propargylamines and indolizines in the absence of solvent and in mild conditions. This method affords the corresponding final products with excellent yields in short reaction times. Additionally, chiral gold(I) complexes with ADCs have been prepared and tried in the enantioselective synthesis of propargylamines.

Topics: Carbene complexes; Catalysts; Multicomponent reaction; Organic compounds and Functional groups; Physical and chemical processes

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Synthesis and supramolecular self-assembly of glutamic acid-based squaramides

Synthesis and supramolecular self-assembly of glutamic acid-based squaramides

Juan V. Alegre-Requena, Marleen Häring, Isaac G. Sonsona, Alex Abramov, Eugenia Marqués-López, Raquel P. Herrera and David Díaz Díaz

Beilstein J. Org. Chem. 201814, 2065–2073.

Abstract: We describe the preparation and characterization of two new unsymmetrical squaramide-based organogelators. The synthesis of the compounds was carried out by subsequent amine condensations starting from dimethyl squarate. The design of the gelators involved a squaramide core connected on one side to a long aliphatic chain and on the other side to a glutamic acid residue. The gelator bearing the free carboxylic groups showed a lower gelation capacity than its precursor diester derivative. Some selected gels were further studied by infrared spectroscopy, rheology and electron microscopy. Critical gelation concentrations and gel-to-sol transition temperatures were also determined for each case. In addition, the superior squaramide diester gelator was compared with an analogue triazole-based gelator in terms of critical gelation concentration, gelation kinetics and thermal phase transition.

Keywords: glutamic acid derivative; organogel; self-assembly; squaramide; supramolecular gel

 

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Urea Activation by an External Brønsted Acid: Breaking Self-Association and Tuning Catalytic Performance

Urea Activation by an External Brønsted Acid: Breaking Self-Association and Tuning Catalytic Performance

Isaac G. Sonsona, Eugenia Marqués-López, Marleen Häring, David Díaz Díaz  and Raquel P. Herrera

Catalysts 20188(8), 305; https://doi.org/10.3390/catal8080305

Abstract: In this work, we hypothesize that Brønsted acids can activate urea-based catalysts by diminishing its self-assembly tendency. As a proof of concept, we used the asymmetric Friedel–Crafts alkylation of indoles with nitroalkenes as a benchmark reaction. The resulting 3-substituted indole derivatives were obtained with better results due to cooperative effects of the chiral urea and a Brønsted acid additive. Such synergy has been rationalized in terms of disassembly of the supramolecular catalyst aggregates, affording a more acidic and rigid catalytic complex.

Keywords: Brønsted acids; Friedel-Crafts; organocatalysis; self-association; synergy; urea

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