Todas las entradas de: Javier García Marín

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.

Adv. Syn. Cat. 2023

Total Synthesis of Laetevirenol A via Regioselective Gold-Catalyzed and Acid-Promoted Cyclizations

Ana Milián, Lucía Sánchez-Jiménez, Jaime Tostado, Juan J. Vaquero, Manuel A. Fernández-Rodríguez*, Patricia García-García*

Adv. Synth. Catal. 2023, Accepted Articles
DOI: 10.1002/ejoc.202300535

The total synthesis of Laetevirenol A, a natural product with antioxidant activity, has been achieved. A gold-catalyzed cycloisomerization of an o-alkenyl-o’-alkynylbiphenyl has been used as the key step for the construction of the phenanthrene moiety present in Laetevirenol A. Several studies in model substrates have been carried out to unveil the effect of substituents in different locations in the outcome of this cyclization, which allowed the design of an appropriate precursor for the fundamental gold-catalyzed cycloisomerization. The suitably functionalized phenanthrene intermediate obtained in this key step could be further transformed into Laetevirenol A via a Friedel-Crafts cyclization, which also turned out to be dependent on the nature of the substituents. Finally, Laetevirenol A was obtained in 10 steps from commercially available substrates, with a 20% global yield.