News

Please find below all relevant news regarding our Group.
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Another collaborative paper for 2024, and our first JACS Au, is already available on-line

06/23/2024
We're extremely happy to share our first JACS Au manuscript has been accepted, and it's now available as Open Access through the publisher website

We are so proud to announce here that our collaborative research article at JACS Au, entitled "De Novo Engineering of Pd-Metalloproteins and Their Use as Intracellular Catalysts" and authored by S. Learte-Aymamí, L. Martínez-Castro, C. González-González, M. Condeminas, P. Martin-Malpartida, M. Tomás-Gamasa, S. Baúlde, J. R. Couceiro, J.-D. Maréchal, M. J. Macias, J. L. Mascareñas and M. E. Vázquez, has been accepted and it's already on-line (gold Open Access) also being selected as "Editors' Choice".


Abstract: The development of transition metal-based catalytic platforms that promote bioorthogonal reactions inside living cells remains a major challenge in chemical biology. This is particularly true for palladium-based catalysts, which are very powerful in organic synthesis but perform poorly in the cellular environment, mainly due to their rapid deactivation. We now demonstrate that grafting Pd(II) complexes into engineered β-sheets of a model WW domain results in cell-compatible palladominiproteins that effectively catalyze depropargylation reactions inside HeLa cells. The concave shape of the WW domain β-sheet proved particularly suitable for accommodating the metal center and protecting it from rapid deactivation in the cellular environment. A thorough NMR and computational study confirmed the formation of the metal-stapled peptides and allowed us to propose a three-dimensional structure for this novel metalloprotein motif.








External link: https://pubs.acs.org/doi/10.1021/jacsau.4c00379

Second in a row: another Angew. Chem. Int. Ed. paper is already available on-line

06/17/2024
Once again, in just two weeks, we are sharing another manuscript in the Synthesis and Catalysis field, also published at ACIE journal

We are really glad to announce here another research article at Angew. Chem. Int Ed., entitled "Skeletal and Mechanistic Diversity  in Ir-Catalyzed Cycloisomerizations of Allene-Tethered Pyrroles and Indoles" and authored by A. Arribas, M. Calvelo, A. Rey, J. L. Mascareñas and F. López, has been accepted and it's already on-line (gold Open Access).


Abstract: Pyrroles and indoles bearing N-allenyl tethers participate in a variety of iridium-catalyzed cycloisomerization processes initiated by a C-H activation step, to deliver a diversity of synthetically relevant azaheterocyclic products. By appropriate selection of the ancillary ligand and the substitution pattern of the allene, the reactions can diverge from simple intramolecular hydrocarbonations to tandem processes involving intriguing mechanistic issues. Accordingly, a wide range of heterocyclic structures ranging from dihydro-indolizines and pyridoindoles to tetrahydroindolizines, as well as cyclopropane-fused tetrahydroindolizines can be obtained. Moreover, by using chiral ligands, these cascade processes can be carried out in an enantioselective manner. DFT studies provide insights into the underlying mechanisms and justify the observed chemo- regio- and stereoselectivities.



Our first Angew. Chem. Int. Ed. for 2024, and second collaborative paper of the year, is already available on-line

06/03/2024
We're really pleased to share our most recent ACIE manuscript has been accepted, and it's now available as Open Access through the publisher website

We are so happy to announce here that our collaborative research article at Angew. Chem. Int Ed., entitled "Gold(III) Auracycles featuring C(sp3)−Au−C(sp2) Bonds: Synthesis and Mechanistic Insights into the Cycloauration Step" and authored by J. A. González, A. Arribas, P. Tian, S. Díaz-Alonso, J. L. Mascareñas, F. López and C. Nevado, has been accepted and it's already on-line (gold Open Access).


Abstract: The direct auration of arenes is a key step in numerous gold-catalyzed reactions. Although reported more than 100 years ago, understanding of its underlying mechanism has been hampered by the difficulties in the isolation of relevant intermediates given the propensity of gold(III) species to undergo reductive elimination. Here, we report the synthesis and isolation of a new family of intriguing zwitterionic [C(sp3)^C(sp2)]-auracyclopentanes, as well as of their alkyl-gold(III) precursors and demonstrate their value as mechanistic probes to study the Csp2-Au bond-forming event. Experimental investigations employing Kinetic Isotope Effects (KIE), Hammett plot, and Eyring analysis provided important insights into the formation of the auracycle. The data suggest a SEAr mechanism wherein the slowest step might be the p-coordination between the arene and the gold(III) center, en route to the Wheland intermediate. We also show that these auracyclopentanes can work as catalysts in several gold-promoted transformations.






External link: https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202402798

Starting February... first ACS Catalysis of 2024 year is hot off the press. And it's OA, have a look at it!

02/09/2024
Happy to share our brand new ACS Catal. manuscript has been accepted, and it's available as Open Access through the publisher website

We are really pleased to announce here that our research article at ACS catal., entitled "Iridium-Catalyzed Tandem Dehydrogenation/Hydroarylation Approach to Synthetically Versatile C2-Alkenyl N–H Indoles" and authored by C. Lázaro-Milla, J. L. Mascareñas and F. López, has been accepted and it's already on-line (gold Open Access).


This work is also dedicated, in memoriam, to Dr. Alejandro Gutiérrez González.

Abstract: Readily available N-carbamoyl indolines can be converted into highly valuable 2-alkenyl and 2-alkyl indoles in a one-pot reaction, through an autotandem catalytic cascade promoted by an iridium complex. The process entails a dehydrogenation reaction initiated by an iridium-promoted C(sp3)–H activation, the addition of the resulting indole to an alkyne -or alkene-partner, and a spontaneous loss of the carbamoyl directing group. Interestingly, the resulting C2-alkenyl indoles can participate in a variety of metal-catalyzed annulations initiated by C–H activation, including formal [4 + 1] and [4 + 2] cycloadditions, as well as cross-dehydrogenative cyclizations, thus enabling a divergent access to a collection of functionally rich nitrogen-containing heterocycles.


External link: https://pubs.acs.org/doi/10.1021/acscatal.3c05841

A brand new collaborative article, at J. Exp. Clin. Cancer Res., is now available on-line through the journal website

01/27/2024
Once again in a week! We are so happy to share another manuscript, this time in collaboration with B. Sainz Jr. group, is already available

We are really glad to announce here that our last collaborative article at the J. Exp. Clin. Cancer Res., entitled "Targeting cancer stem cell OXPHOS with tailored ruthenium complexes as a new anti-cancer strategy" and authored by S. Alcalá, L. Villarino, [...] (25 further authors), J. L. Mascareñas and B. Sainz J., is already available through the journal website as a gold-open access paper.

Do not miss these latest results for this joint project among B. Sainz Jr. research group and ours!


Abstract: The coordination complex Ru1 represents not only an exciting new anti-cancer agent, but also a molecular tool to dissect the role of OXPHOS in CSCs. Results indicating that the compound is safe, non-toxic and highly effective in vivo are extremely exciting, and have allowed us to uncover unprecedented mechanistic possibilities to fight different cancer types based on targeting CSC OXPHOS




External link: https://link.springer.com/article/10.1186/s13046-023-02931-7?utm_source=rct_congratemailt&utm_medium=email&utm_campaign=oa_20240127&utm_content=10.1186/s13046-023-02931-7

Our first paper of the year 2024 is on-line, and it's a JACS

01/26/2024
Happy to share our most recent J. Am. Chem. Soc. manuscript has been accepted, and it's available as Open Access through the publisher website

We are really pleased to announce here that our research article at J. Am. Chem. Soc., entitled "Intracellular Synthesis of Indoles Enabled by Visible-Light Photocatalysis" and authored by C. D'Avino, S. Gutiérrez, M. J. Feldhaus, M. Tomás-Gamasa and J. L. Mascareñas has been accepted and it's already on-line (gold Open Access).


This work is dedicated to the memory of our beloved PhD student and friend Alejandro Gutiérrez-González.

Abstract: Performing abiotic synthetic transformations in live cell environments represents a new, promising approach to interrogate and manipulate biology and to uncover new types of biomedical tools. We now found that photocatalytic bond-forming reactions can be added to the toolbox of bioorthogonal synthetic chemistry. Specifically, we demonstrate that exogenous styryl aryl azides can be converted into indoles inside living mammalian cells under photocatalytic conditions.



External link: https://pubs.acs.org/doi/10.1021/jacs.3c13647

A brand new stand-alone chapter in the prestigious Reference Collection in Chemistry, Molecular Sciences and Chemical Engineering is now available on-line

01/08/2024
Our most recent compilation concerning 'Catalytic Addition of C–H Bonds Across C–C π-Bonds' has been published on line

We are so happy to announce here the work "Catalytic Addition of C–H Bonds Across C–C π-Bonds" authored by A. Arribas, C. Lázaro-Milla, J. L. Mascareñas and F. López, is already available through the website of Reference Collection in Chemistry, Molecular Sciences and Chemical Engineering as a stand-alone chapter


Abstract: Transition metal-catalyzed hydrocarbonations of C−C unsaturated substrates, namely the addition of a C–H bond across an unsaturated system, have emerged as powerful synthetic tools to increase molecular complexity. Those processes involving the oxidative addition of the C–H bond to the metal catalyst are particularly interesting due to their simplicity and an atom-economy. Albeit 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, nickel, cobalt and even iron complexes. In many cases, these reactions have a different course depending on the metal and ancillary ligands used. In this review, we aim to provide a detailed and informative journey, from the early pioneering examples in the field, most of them based on ruthenium, to the most recent developments. 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 metal catalyst and C–C unsaturated system that is used as hydrocarbonation partner (alkene, allene, diene or alkyne). Importantly, we discuss the mechanistic foundations of the methods, highlighting the differences between metals catalysts, and emphasize the current opportunities.




External link: https://www.sciencedirect.com/science/article/abs/pii/B9780323960250000193?via%3Dihub

Second in a row: another collaborative article, this time at Org. Lett., is now available on-line

11/10/2023
Once again in a week, we are so happy to share another manuscript in collaboration with I. Fernández group is available through the journal website

We are really glad to announce here that another collaborative article accepted at Org. Lett., entitled "Cobalt(I)-Catalyzed (3 + 2 + 2) Cycloaddition between Alkylidenecyclopropanes, Alkynes, and Alkenes" and authored by E. da Concepción, C. Lázaro, I. Fernández, J. L. Mascareñas and F. López, is already available through the journal website.

Abstract: Cobalt(I) catalysts equipped with bisphosphine ligands can be used to promote formal (3 + 2 + 2) intramolecular cycloadditions of enynylidenecyclopropanes of type 1. The method provides synthetically appealing 5,7,5-fused tricyclic systems in good yields and with complete diastereo- and chemoselectivity. Interestingly, its scope differs from that of previously reported annulations based on precious metal catalysts, specifically rhodium and palladium. Noticeably, density functional theory calculations confirm that the mechanism of the reaction is also different from those proposed for these other catalysts.


External link: https://pubs.acs.org/doi/10.1021/acs.orglett.3c03511

A new article at Adv. Synth. Catal. is already available on-line

11/06/2023
So happy to announce our last manuscript concerning "Cobalt-catalyzed Intramolecular Cycloadditions" is available through the journal website

We are very glad to share here that our article at Adv. Synth. Catal., entitled "Cobalt-catalyzed Intramolecular Cycloadditions of Alkenylidenecyclopropanes with Alkenes and Dienes" and authored by E. Da Concepción, I. Fernández, J. L. Mascareñas and F. López, is already available through the journal website.

Abstract: Low-valent cobalt complexes equipped with phosphorous type of ligands can promote the intramolecular (3+2) cycloaddition of alkylidenecyclopropanes (ACPs) with alkenes and with allenes. Dienes can also be used as partners, but they afford seven-membered cycloadducts. The reactions are fully diastereoselective and, in some cases, we also observed moderate enantioselectivities, especially when using chiral phosphite ligands




External link: https://onlinelibrary.wiley.com/doi/10.1002/adsc.202301040