External link: http://geqo.es/geqo-awards-2018/

External link: https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0037-1610497

Abstract:

We report an Ir(I)-catalyzed cycloisomerization methodology that provides access to carbocyclic systems bearing exo-alkene moieties from alkynyl-equipped acyclic precursors. The method relies on the C-H activation of olefinic and (het-ero)aromatic C(sp2)–H bonds, followed by an exo-cyclization to a tethered alkyne, and provides interesting cyclic diene products that are amenable of further elaboration. Importantly, DFT calculations suggests that, in contrast to related hydrocarbonations of alkenes in which either migratory insertions or C-C reductive eliminations have been suggested to be rate determining, in our reac-tions, the energetic barrier of these steps is lower than that of the previous C–H activation.

External link: https://pubs.acs.org/doi/abs/10.1021%2Facscatal.8b02139

"Intracellular deprotection reactions mediated by palladium complexes equipped with designed phosphine ligands", authored by M. Martínez-Calvo, J. R. Couceiro, P. Destito, J. Rodriguez, J. Mosquera and J. L. Mascareñas, is our latest paper at ACS Catalysis.

Abstract:

Discrete palladium (II) complexes featuring purposely designed phosphine ligands can promote depropargylation and deallylation reactions in cell lysates. The performance of these complexes is superior to that of other palladium sources, which apparently are rapidly deactivated in such hostile complex media. This good balance between reactiv-ity and stability allows the use of these discrete phosphine palladium complexes in living mammalian cells, whereby they can mediate similar transformations. The presence of a phosphine ligand in the coordination sphere of palladi-um also provides for the introduction of targeting groups, such as hydrophobic phosphonium moieties, which facili-tate the accumulation of the complexes in mitochondria.

External link: https://pubs.acs.org/doi/10.1021/acscatal.8b01606

ABSTRACT: We report a highly enantioselective [3C + 2C] intramolecular cycloaddition of alkylidenecyclopropanes (ACPs) and alkenes. The best results are obtained by using sterically demanding chiral phosphoramidite ligands derived from Vapol. Moreover, we also show that related, but less bulky, phosphoramidites can also lead to very effective [4C + 3C] cycloadditions when dienes, instead of alkenes, are used as reacting partners. The reactions provide a practical, simple, and selective access to optically active, synthetically appealing 5,5- and 5,7-bicyclic systems.

External link: https://pubs.acs.org/doi/10.1021/acscatal.8b01296