Category Archives: Noticias

Org. Lett 04.24

Synthesis of Seven- and Eight-Membered Rings by a Brønsted Acid Catalyzed Cationic Carbocyclization of Biphenyl Embedded Enynes

Jaime Tostado , Ana Milián, Juan J. Vaquero, and Manuel A. Fernández-Rodríguez*

Org. Lett. 2024, ASAP
DOI: acs.orglett.4c00647

A Brønsted acid catalyzed cyclization of o-alkenyl-o′-alkynylbiaryls for the synthesis of biologically relevant dibenzo-fused medium-sized rings has been developed. The outcome of the cyclization is determined by the nature of the substituent at the alkyne, with arenes favoring seven-membered rings and alkyl substituents producing eight-membered rings. These reactions proceed via a vinyl cation, which is captured by water and, notably, by C-nucleophiles, such as electron-rich (hetero)arenes.

Álvaro González PhD Defense

On April 12th, Álvaro González Molina successfully defended his doctoral thesis under the supervision of Dr. Jose Luis Aceña Bonilla and Prof. Juan José Vaquero: “Síntesis de aminoácidos bicíclicos y peptidomiméticos conformacionalmente restringidos derivados de prolina y ácido pipecólico”

Thanks to all members of the tribunal: Dr. Javier García Marín, Dr. Ángela  Martín-Serrano Ortiz and Dr.  María Sánchez Roselló

Congratulations to Dr. González!

 

Clara Mañas PhD Defense

On April 4th, Clara Mañas successfully defended her doctoral thesis under the supervision of Dr. Estíbaliz Merino: “Design and study of novel reactivities of alkynylazobenzenes”

Thanks to all members of  thesis tribunal: Dr. Teresa Quirós, Dr. Eva Maya and Dr. María Ribagorda

Congratulations to Dr. Mañas!

Angewandte Chemie 03.24

Asymmetric, Remote C(sp3)−H Arylation via Sulfinyl-Smiles Rearrangement

Yawen Hu, Cédric Hervieu,  Dr. Estíbaliz Merino*, Prof. Cristina Nevado*

Angew. Chem. Int. Ed. 2024, Early View
DOI: anie.202319158

An efficient asymmetric remote arylation of C(sp3)−H bonds under photoredox conditions is described here. The reaction features the addition radicals to a double bond followed by a site-selective radical translocation (1,n-hydrogen atom transfer) as well as a stereocontrolled aryl migration via sulfinyl-Smiles rearrangement furnishing a wide range of chiral α-arylated amides with up to >99 : 1 er. Mechanistic studies indicate that the sulfinamide group governs the stereochemistry of the product with the aryl migration being the rate determining step preceded by a kinetically favored 1,n-HAT process.

Org. Lett 02.24

Visible Light-Mediated Heterodifunctionalization of Alkynylazobenzenes for 2H-Indazole Synthesis

Clara Mañas and Estíbaliz Merino*

Org. Lett. 2024, ASAP
DOI: acs.orglett.4c00097

We disclose the heterodifunctionalization of alkynylazobenzenes promoted exclusively by visible light in the absence of any transition metal and/or photocatalyst. This reaction features excellent regioselectivity on a broad variety of substrates with perfect atom economy. Alcohols, carboxylic acids, thiols, amides, heterocycles, and even water are suitable substrates for the promotion of the oxyamination, sulfenoamination, and diamination reactions. In this manner, biologically active indazole scaffolds can be rapidly assembled from alkyne feedstocks.

Nat. Chem. 2024

Chiral arylsulfinylamides as reagents for visible light-mediated asymmetric alkene aminoarylations

Cédric Hervieu, Mariia S. Kirillova, Yawen Hu, Sergio Cuesta-Galisteo, Estíbaliz Merino*, Cristina Nevado

Nat. Chem. 2024, Accepted Articles
DOI: 10.1038/s41557-023-01414-8

Two- or one-electron-mediated difunctionalizations of internal alkenes represent straightforward approaches to assemble molecular complexity by the simultaneous formation of two contiguous Csp3 stereocentres. Although racemic versions have been extensively explored, asymmetric variants, especially those involving open-shell C-centred radical species, are much more limited both in number and scope. Here we describe enantioenriched arylsulfinylamides as all-in-one reagents for the efficient asymmetric, intermolecular aminoarylation of alkenes. Under mild photoredox conditions, nitrogen addition of the arylsulfinylamide onto the double bond, followed by 1,4-translocation of the aromatic ring, produce, in a single operation, the corresponding aminoarylation adducts in enantiomerically enriched form. The sulfinyl group acts here as a traceless chiral auxiliary, as it is eliminated in situ under the mild reaction conditions. Optically pure β,β-diarylethylamines, aryl-α,β-ethylenediamines and α-aryl-β-aminoalcohols, prominent motifs in pharmaceuticals, bioactive natural products and ligands for transition metals, are thereby accessible with excellent levels of regio-, relative and absolute stereocontrol.