Amparo Sanz-Marco

Electrochemically driven organic transformations have emerged as a versatile approach for developing more sustainable synthetic methods, offering precise control over redox processes while replacing stoichiometric oxidants with electricity. In this context, an efficient electrochemical strategy for the generation of highly reactive o-quinonediimines from readily available o-phenylenediamines is reported. Anodic oxidation enables their in-situ formation and subsequent cycloaddition with diverse alkenes, affording valuable tetrahydroquinoxaline cycloadducts in good to excellent yields. The broad substrate scope, together with the successful derivatization of the products, highlights the synthetic utility of this approach.

The utility of underexplored vinylogous isocyano esters in the synthesis of oxazole derivatives is demonstrated herein. A divergent base-promoted tandem (3+2) cyclization–isomerization reaction with aldehydes divergently yields bisubstituted oxazoles (up to 90% in MeOH with 2 equiv of DBU) or oxazolines (up to 80% in CH2Cl2 with 1 equiv of DBU) A density functional theory (DFT) study of these reactions supports the experimental evidence, confirming the mechanism and selectivity of this divergent process.

The DBU-mediated tandem reaction of dicyanoalkenes with enantiomerically pure conjugated sulfinyl iminoesters give rise to the formation of tetracyclic scaffolds with formation of 3 bonds and 4 stereocenters in good diastereo- and enantioselectivies.

An enantioselective strategy for the synthesis of chiral 3-alkyl-1,5-functionalized 1,4-diynes is reported. The method involves a highly enantioselective organocatalytic conjugate addition of isoxazol-5(4H)-ones to nitroenynes followed by a Zard-type transformation under one-pot conditions yielding chiral skipped diynes in good overall yields and with excellent enantioselectivities. This study highlights the synthetic versatility of the isoxazol-5(4H)-one scaffold and its value as a platform for accessing structurally diverse and synthetically relevant building blocks.

A cinchonine-derived thiourea catalyst enables the organocatalytic desymmetrization of bisphenol derivatives through a phosphorylation reaction, providing chiral 1,1-diarylalkanes and triarylmethanes in good yields and excellent enantioselectivities.

We report the synthesis of chiral sulfonyl fluorides bearing a carbon quaternary stereocenter. A commercially available organocatalyst (DHQD)₂AQN enables the enantioselective addition of 3-substituted oxindoles to ethenesulfonyl fluoride (ESF), achieving excellent yields (27-99%) and enantioselectivities (89-99% ee) for 3-arylsubstituted oxindoles. This methodology shows high functional group tolerance, as demonstrated by successfully engaging halides, ethers, nitriles, acetals, ketals, or heteroaromatic substituents. The utility of the described products was proven by various synthetic transformations, including SuFEx reactions with complex biomolecules.

Vinylogous isocyano esters were prepared for the first time. They react with aldehydes to give chiral oxazolines bearing a pendant conjugated ester under synergistic silver/organocatalysis. The reaction is carried out using a bifunctional squaramide in combination with silver oxide and performs well with a number of aryl, heteroaryl, and cycloalkyl aldehydes, providing the expected heterocycles in good yields with good diastereoselectivity and enantiomeric excesses ranging from 60% to 95% ee.

Las asignaturas experimentales, como los laboratorios de química orgánica en el Grado en Química, son a menudo difíciles de evaluar de manera objetiva e individualizada. En esta comunicación se presenta el proyecto de innovación educativa UV-SFPIE_PIEE-3328892, desarrollado en la Universitat de València, cuyo objetivo ha sido mejorar la evaluación y superar las limitaciones existentes en las asignaturas de Laboratorio de Química Orgánica I y II del Grado en Química. Para ello, se han diseñado rúbricas de evaluación que buscan garantizar una valoración objetiva, coherente y uniforme por parte del profesorado. Estas rúbricas están orientadas a facilitar la evaluación formativa de las prácticas, teniendo en cuenta la adquisición de competencias por parte del alumnado. Posteriormente, las rúbricas se implementaron en grupos reducidos de estas asignaturas experimentales, y se realizaron encuestas de valoración entre los estudiantes participantes, con el fin de evaluar la efectividad de las rúbricas e identificar posibles áreas de mejora.

An efficient enantioselective organocatalytic conjugate addition of isoxazol‐5(4 H )‐ones to aurone‐derived azadienes under mild conditions has been developed. This methodology provides access to a wide range of chiral compounds featuring both benzofuran and isoxazole scaffolds in their structures achieving high yields and stereo control. Furthermore, the resulting adducts can be readily transformed into chiral β‐benzofuran‐branched carbonyl compounds in high yields and enantioselectivity in one‐pot reaction through hydrolysis‐decarboxylation of the isoxazole ring.

A valuable vinylogous addition reaction between 4-alkylidene-5-aminopyrazoles and alkyl trifluoropyruvates leading to highly functionalized tertiary alcohols bearing a trifluoromethyl group and a pyrazole ring is presented. The corresponding trifluoromethyl alcohols are obtained in moderate to good yields (up to 80%) and high diastereoselectivity (up to 7:1).