News

Please find below all relevant news regarding our Group.
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Our last publication at Angew. Chem. Int. Ed. is available on-line

06/16/2021
We are very glad to announce our last paper about bioorthogonal chemical reactions is at ANIE Early view

We are very happy to share here that our research article at Angew. Chem. Int. Ed., entitled "Bioorthogonal Azide–Thioalkyne Cycloaddition Catalyzed by Photoactivatable Ruthenium(II) Complexes" and authored by A. Gutiérrez-González, P. Destito, J. R. Couceiro, C. Pérez-González F. López and J. L. Mascarenas, has been accepted and it's already available through the journal website.

Abstract: Tailored ruthenium sandwich complexes bearing photoresponsive arene ligands can efficiently promote azide–thioalkyne cycloaddition (RuAtAC) when irradiated with UV light. The reactions can be performed in a bioorthogonal manner in aqueous mixtures containing biological components. The strategy can also be applied for the selective modification of biopolymers, such as DNA or peptides. Importantly, this ruthenium-based technology and the standard copper-catalyzed azide–alkyne cycloaddition (CuAAC) proved to be compatible and mutually orthogonal








External link: https://onlinelibrary.wiley.com/doi/10.1002/anie.202103645

Congrats to David, on his successful PhD defense

05/28/2021
David Cagiao Marcote has defended today his PhD Thesis at the Faculty of Chemistry, USC

David Cagiao Marcote is our brand new Doctor in the group, after defending his PhD entitled "Novas Estratexias Sintéticas Baseadas en Catálise de Ouro".

This PhD work, supervised by Prof. Mascareñas and Dr. López, has received the highest qualification by the jury committee.

Congrats David!!!




External link: https://twitter.com/ciqususc/status/1398252322191458306

Our new paper at Bioorg. Chem. in colaboration with Prof. Mollica is already on-line

03/22/2021
So happy to share our last collaboration with Mollica's group is already published in the Bioorganic Chemistry journal

We are very glad to announce here that our research article at Bioorg. Chem. in collaboration with Mollica's group, entitled "A novel β-hairpin peptide derived from the ARC repressor selectively interacts with the major groove of B-DNA" and authored by A. Stefanucci, J. Amato, D. Brancaccio, B. Pagano, A. Randazzo, F. Santoro, L. Mayol, S. Learte, J. Rodríguez, J. L. Mascareñas, E. Novellino, A. Carotenuto and A. Mollica, has been accepted and it's already available through the journal website.

Abstract: Transcription factors (TFs) have a remarkable role in the homeostasis of the organisms and there is a growing interest in how they recognize and interact with specific DNA sequences. TFs recognize DNA using a variety of structural motifs. Among those, the ribbon-helix-helix (RHH) proteins, exemplified by the MetJ and ARC repressors, form dimers that insert antiparallel β-sheets into the major groove of DNA. A great chemical challenge consists of using the principles of DNA recognition by TFs to design minimized peptides that maintain the DNA affinity and specificity characteristics of the natural counterparts. In this context, a peptide mimic of an antiparallel β-sheet is very attractive since it can be obtained by a single peptide chain folding in a β-hairpin structure and can be as short as 14 amino acids or less. Herein, we designed eight linear and two cyclic dodeca-peptides endowed with β-hairpins. Their DNA binding properties have been investigated using fluorescence spectroscopy together with the conformational analysis through circular dichroism and solution NMR. We found that one of our peptides, peptide 6, is able to bind DNA, albeit without sequence selectivity. Notably, it shows a topological selectivity for the major groove of the DNA which is the interaction site of ARC and many other DNA-binding proteins. Moreover, we found that a type I’ β-hairpin folding pattern is a favorite peptide structure for interaction with the B-DNA major groove. Peptide 6 is a valuable lead compound for the development of novel analogs with sequence selectivity.

See limited-time downloadable version at https://authors.elsevier.com/c/1cqckAHs8WTkL



External link: https://www.sciencedirect.com/science/article/abs/pii/S0045206821002133

Our last paper at 'The Journal of the American Chemical Society' is available as Article ASAP

03/03/2021
We are very glad to announce our first 2021 J. Am. Chem. Soc. paper is already on-line

We are very happy to share here that our research article at J. Am. Chem. Soc., entitled "Kinetic Resolution of Allyltriflamides through a Pd-Catalyzed C–H Functionalization with Allenes: Asymmetric Assembly of Tetrahydropyridines" and authored by J. M. González, B. Cendón, J. L. Mascarenas and M. Gulías, has been accepted and it's already available through the journal website.


Abstract: Enantioenriched, six-membered azacycles are essential structural motifs in many products of pharmaceutical or agrochemical interest. Here we report a simple and practical method for enantioselective assembly of tetrahydropyridines, which is paired to a kinetic resolution of α-branched allyltriflamides. The reaction consists of a formal (4+2) cycloaddition between the allylamine derivatives and allenes and is initiated by a palladium(II)-catalyzed C–H activation process. Both the chiral allylamide precursors and the tetrahydropyridine adducts were successfully obtained in high yields, with excellent enantioselectivity (up to 99% ee) and selectivity values of up to 127.






External link: https://pubs.acs.org/doi/10.1021/jacs.1c01929

Our first publication for 2021 is on-line

01/20/2021
Pleased to announce our most recent Angew. Chem. Int. Ed. manuscript has been accepted, and it's already available

We are very happy to share here that our research article at Angew. Chem. Int. Ed., entitled "Highly Enantioselective Cobalt‐Catalyzed (3 + 2) Cycloadditions of Alkynylidenecyclopropanes" and authored by E. Da Concepción, I. Fernández, J. L. Mascarenas and F. López, has been accepted and it's already available through the journal website.

Abstract: Low‐valent cobalt complexes equipped with chiral ligands can efficiently promote highly enantioselective (3+2) cycloadditions of alkyne‐tethered alkylidenecyclopropanes. The annulation allows to assemble bicyclic systems containing five‐membered rings in good yields and with excellent enantiomeric ratios. We also present a mechanistic discussion based on experimental and computational data, which support the involvement of Co(I)/Co(III) catalytic cycles




External link: https://onlinelibrary.wiley.com/doi/10.1002/anie.202015202

Our last review at 'Chemical Society Reviews' is available as accepted manuscript

09/14/2020
So glad to share our revision article is available as Advance Article at Chem. Soc. Rev.

We are starting 2020-2021 academic course and we have good news... our revision publication at Chemical Society Revies journal, entitled "Catalytic addition of C–H bonds across C–C unsaturated systems promoted by iridium(i) and its group IX congeners" and authored by D. Fernández, J. L. Mascareñas and F. López is already on-line.

Abstract:  Transition metal-catalyzed hydrocarbonations of unsaturated substrates have emerged as powerful synthetic tools for increasing molecular complexity in an atom-economical manner. Although this field was traditionally dominated by low valent rhodium and ruthenium catalysts, in recent years, there have been many reports based on the use of iridium complexes. In many cases, these reactions have a different course from those of their rhodium homologs, and even allow performing otherwise inviable transformations. In this review we aim to provide an informative journey, from the early pioneering examples in the field, most of them based on other metals than iridium, to the most recent transformations catalyzed by designed Ir(I) complexes. The review is organized by the type of C–H bond that is activated (with C sp2, sp or sp3), as well as by the C–C unsaturated partner that is used as a hydrocarbonation partner (alkyne, allene or alkene). Importantly, we discuss the mechanistic foundations of the methods highlighting the differences from those previously proposed for processes catalyzed by related metals, particularly those of the same group (Co and Rh).



External link: https://pubs.rsc.org/en/content/articlelanding/2020/CS/D0CS00359J#!divAbstract