Category Archives: 2024

Tostado et al. Org Lett. 2024;26(16):3343-3348. Synthesis of Seven- and Eight-Membered Rings by a Brønsted Acid Catalyzed Cationic Carbocyclization of Biphenyl Embedded Enynes.

Publications > Tostado et al

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

Universidad de Alcalá (IRYCIS). Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Autovía A-II, Km 33.1, 28805-Alcalá de Henares, Madrid, Spain.

Abstract

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.

Hu et al. Angew Chem Int Ed Engl. 2024;:e202319158. Asymmetric, Remote C(sp(3) )-H Arylation via Sulfinyl-Smiles Rearrangement.

Publications > Hu et al

Asymmetric, Remote C(sp(3) )-H Arylation via Sulfinyl-Smiles Rearrangement.

1. Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH 8057, Zurich, Switzerland.  2. Departamento de Química Orgánica y Química Inorgánica Instituto de Investigación Química "Andrés M. del Río" (IQAR). Facultad de Farmacia, Universidad de Alcalá Alcalá de Henares, 28805, Madrid, Spain.  3. Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Ctra. de Colmenar Viejo, Km. 9.100, 28034, Madrid, Spain.

Abstract

An efficient asymmetric remote arylation of C(sp(3) )-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.

Renedo et al. Advanced Synthesis & Catalysis. 2024;366(9):2079 -2089. Gold-Catalyzed Tandem Oxidation-Migration of 3-Propargyl Indoles: Synthesis of α-Indol-3-yl α,β-Unsaturated Carbonyls.

Publications > Renedo et al

Gold-Catalyzed Tandem Oxidation-Migration of 3-Propargyl Indoles: Synthesis of α-Indol-3-yl α,β-Unsaturated Carbonyls.

Resumen

No hay resumen

Mañas and. Org Lett. 2024;26(9):1868-1873. Visible Light-Mediated Heterodifunctionalization of Alkynylazobenzenes for 2H-Indazole Synthesis.

Publications > Mañas and

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

1. Universidad de Alcalá, Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Andrés del Río (IQAR), Facultad de Farmacia, 28805 Alcalá de Henares, Madrid, Spain.  2. Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Ctra. de Colmenar Viejo, Km. 9.100, 28034 Madrid, Spain.

Abstract

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.

Hervieu et al. Nat Chem. 2024;:. Chiral arylsulfinylamides as reagents for visible light-mediated asymmetric alkene aminoarylations.

Publications > Hervieu et al

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

1. Department of Chemistry, University of Zurich, Zurich, Switzerland.  2. Universidad de Alcalá, Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Andrés M. del Río (IQAR), Facultad de Farmacia, Madrid, Spain.  3. Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.

aestibaliz.merino@uah.es  bestibaliz.merino@uah.es

Abstract

Two- or one-electron-mediated difunctionalizations of internal alkenes represent straightforward approaches to assemble molecular complexity by the simultaneous formation of two contiguous Csp(3) 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.