Archivo de la categoría: Noticias

Nuevo artículo, ChemSusChem 05.23

Mizoroki–Heck Macrocyclization Reactions at 1 M Concentration Catalyzed by Sub-nanometric Palladium Clusters

Francisco Garnes–Portolés, Estíbaliz Merino, Antonio Leyva–Pérez*

ChemSusChem 2023, Accepted Articles
DOI: 10.1002/cssc.202300200

Mizoroki-Heck macrocyclization reactions are carried out at 1M concentration with ligand-free Pd cluster catalysts either in solution or supported on solids. Mechanistic studies unveil the essential role of the fluxional Pd cluster to accommodate, at the same time, the reacting groups, to give the intramolecular vs the intermolecular coupling reaction at this high concentration, enabling (in-flow) solid-catalyzed macrocyclization reactions.

Nuevo artículo, Synthesis 03.23

Visible-Light-Mediated Regioselective Chlorosulfonylation of Acrylamides

Mercedes Zurro, Sergio Torres-Oya, Guillermo G. Otárola, Juan José Vaquero, Estíbaliz Merino*

Synthesis 2023, Special Issue dedicated to Prof. Cristina Nevado, recipient of the 2021 Dr. Margaret Faul Women in Chemistry Award
DOI: 10.1055/s-0042-1751424

A one-step chlorosulfonylation of acrylamides via a photocatalytic redox process is described. This reaction provides α-chlorosulfonylamides with a quaternary center with high regioselectivity via radical process. It is amenable to a broad range of substrates and the products are obtained in moderate to good yields.

Nuevo artículo, Org. Biomol. Chem. 03.23

Gold-catalyzed endo-selective cyclization of alkynylcyclobutanecarboxamides: synthesis of cyclobutane-fused dihydropyridones

M. Soledad Garre, Guillermo G. Otárola, Estíbaliz Merino, David Sucunza, Enrique Aguilar, M. Teresa Quirós, Juan J. Vaquero* and Patricia García-García*

Org. Biomol. Chem. 2023, Advance Article
DOI: 10.1039/D3OB00051F

Cyclobutane-fused dihydropyridones can be efficiently synthesized by a completely endo-selective gold-catalyzed cyclization of alkynylcyclobutanes bearing an appended amide, which proceeds under mild conditions. The observed selectivity, which is reversed from that previously observed for the cyclization of related alcohols and acids, is supported by DFT calculations.

Participación XVIII SJIQ

XVIII Simposio de Jóvenes Investigadores Químicos de la RSEQ

Sevilla, 21 – 28 noviembre

– Oral:
· Metal-free synthesis of 3-trifluoromethypyrazoles: [3+2] cyclization of styrenes and 2,2,2-trifluorodiazoethane
Julia Altarejos, David Sucunza, Juan J. Vaquero, Estíbaliz Merino, and Javier Carreras

– Póster:
· Visible-light mediated synthesis of indazoles
Clara Mañas, Estíbaliz Merino

– Póster:
· Synthesis of novel five membered organoborate heterocycles and their use in cross-coupling reactions
Isabel Valencia, Patricia Garcia-Garcia, David Sucunza, Adrián Pérez-Redondo, Juan J. Vaquero

Nuevo artículo, Synthesis 11.22

Synthesis of five-membered organoborate heterocycles via a metal-free carboboration and their use in cross-coupling reactions

Isabel Valencia, David Sucunza, Patricia García-García, Adrián Pérez-Redondo, Juan Vaquero López

Synthesis 2022, Accepted Articles
DOI: 10.1055/a-1979-6009

Treatment of various vinylbenzopyridines with allyl(dichloro)borane affords five-membered organoborate heterocycles via a metal-free carboboration. The reaction between these organoborates and Grignard reagents increases the number of derivatives belonging to this novel family of four-coordinate organoboron compounds. Some of them were used as reagents in phenylations and methylations in moderate to high yields under standard palladium-catalyzed cross-coupling reaction conditions.

Nuevo artículo, Adv. Synth. Catal. 10.22

Synthesis of Phenanthrene-based Polycycles by Gold(I)-Catalyzed Cyclization of Biphenyl-Embedded Trienynes

Ana Milián, Patricia García-García,* Juan J. Vaquero, Roberto Sanz, Manuel Ángel Fernández-Rodríguez*

Adv. Synth. Catal. 2022, Accepted Articles
DOI: 10.1002/adsc.202200887

Gold(I)-catalyzed cyclization of o-alkenyl-o’-alkynylbiaryls in the presence of external or internal nucleophiles provides a straightforward access to phenanthrene-based polycycles, which are of considerable interest in materials science. Thus, their reactions with alcohols yield functionalized dihydrophenanthrenes, in a process that can also be carried out intramolecularly to provide phenanthrene-derived heteropolycyclic compounds. Moreover, benzo[b]triphenylenes can be synthesized from o-methoxyvinyl-o’-alkynylbiaryls, in a reaction in which an (hetero)aryl substituent at the triple bond acts as an internal nucleophile.

Nuevo artículo, Dyes and Pigments 08.22

Highly efficient unbridged D-A+(D) chromophores based on the quinolizinium cation for nonlinear optical (NLO) applications

Esmeralda Sánchez-Pavón, Javier Recio, Marco Antonio Ramirez, Belen Batanero, Koen Clays, Francisco Mendicuti, Gema Marcelo, Thais Carmona, Obis Castaño, Silvia Angelova, Jose L. Andres, Juan J. Vaquero, Ana M. Cuadro*

Dyes and Pigments 2022, ASAP
DOI: 10.1016/j.dyepig.2022.110323

Novel charged D-A+ chromophores based on quinolizinium cations as acceptor unit have been prepared by treating haloquinolizinium salts with N-heteroarylstannanes under Stille reaction conditions. This approach provides an easy access to potential one-dimensional D-A+ and two-dimensional D-A+-D chromophores in which the acceptor moiety (A+) is the simple azonia cation and the donors are different π-rich N-heterocycles. The first hyperpolarizabilities (β) were measured by hyper-Rayleigh scattering experiments and the experimental data confirmed that the inherent polarization between donor and acceptor fragments modulates the NLO properties. The electronic structures and properties (including both the linear and nonlinear optical properties) of the quinolizinium chromophores were examined by theoretical (DFT, HF and MP2) calculations. A promising strategy for the rational design of D-A building blocks to create new organic-based NLO materials is proposed..

Nuevo artículo, Org.Lett 08.22

Synthesis of BN-Polyarenes by a Mild Borylative Cyclization Cascade

Ester Sans-Panadés, Juan J. Vaquero, Manuel A. Fernández-Rodríguez*, Patricia García-García*

Org. Lett. 2022, ASAP
DOI: 10.1021/acs.orglett.2c02477

Reaction of BCl3 with suitably substituted o-alkynylanilines promotes a cascade reaction in which BN-polycyclic compounds are obtained via the formation of two new cycles and three new bonds in a single operational step. The reaction is highly efficient and takes place at room temperature, providing a very mild and straightforward strategy for the preparation of BN-aromatic compounds, which can be further transformed into a variety of BN-PAHs with different polycyclic cores and substituents.

Nuevo artículo, EurJOC 07.22

Synthesis of Tri- and Tetrasubstituted Alkenyl Boronates from Alkynes

Julia Altarejos, Antonio Valero, Rubén Manzano,* Javier Carreras*

Eur. J. Org. Chem. 2022, #NextGenOrgChem
DOI: 10.1002/ejoc.202200521

The synthesis of organoboron compounds have attracted the attention of the synthetic community. In particular, molecules with C(sp2)-B bonds enable the transformation to new C−C or C-heteroatom bonds by well-established methodologies. Alkenyl boronates have the possibility for further conversion of the boron moiety or functionalization of the double bond. This review gives an overview on the recent methodologies for the selective preparation of the challenging highly substituted alkenyl boronates from alkynes.