Transannular Enantioselective (3 + 2) Cycloaddition of Cycloalkenone Hydrazones under Bronsted Acid Catalysis.

[EN]Hydrazones derived from cycloalkenones undergo an enantioselective transannular formal (3 + 2) cycloaddition catalyzed by a chiral phosphoric acid. The reaction provides high yields and excellent stereocontrol in the formation of complex adducts with one or two α-tertiary amine moieties at the ring fusion, and these can be converted into very versatile stereodefined decalin- or octahydro-1H-indene-derived 1,3-diamines through simple reductive N–N cleavage.This research was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU) through projects FEDER-PID2020-118422-GB-I00, FEDER-PID2019-109674-GB-I00 and FPI fellowship to J.S. and by the Basque Government (IT908-16). J.S. acknowledges the Spanish MCIU for an FPI fellowship

Correlation between magnetic and transport properties in nanocrystalline Fe thin films: A grain-boundary magnetic disorder effect

We report on transport and magnetic measurements of islanded Fe(110) thin films. The electrical resistivity exhibits an anomalous increase at low temperatures, which disappears under the action of a magnetic field. Since such an anomaly completely disappears under the action of a magnetic field, it is inferred that it originates from spin-dependent scattering. We interpret the strong changes in the spin-dependent scattering in our films to be due to a low-temperature spin freezing of the island boundary magnetic regions that impedes ferromagnetic exchange between islands. A consequence of this magnetic behavior is the random arrangement of the individual magnetization, determined by the magnetocrystalline anisotropy of each island, resulting in an increase of the resistivity below the freezing temperature.Z.S. and J.L.M. acknowledge the Comunidad de Madrid for financial support. Work was performed under the financial support of the Comunidad de Madrid and the Spanish Commission of Science and Technology.Peer reviewe

Recent Advances in the Prins Reaction

The Prins reaction is a very convenient synthetic platform for the preparation of oxygen-containing heterocyclic compounds, especially tetrahydropyrans and tetrahydrofurans. While this reaction has been extensively used by synthetic chemists since its discovery, the last years have witnessed impressive improvements in its performance and scope and especially in the development of new catalytic and enantioselective versions. This mini-review presents these recent advances through selected representative examples.The authors thank the Spanish Agencia Estatal de Investigacion (FEDER-PID2020-118422-GB-I00) and the Basque Government (Grupos IT1558-22) for financial support