Enantioselective rhodium-catalyzed coupling of arylboronic acids, 1,3-enynes, and Imines by alkenyl-to-allyl 1,4-rhodium(I) migration

A chiral rhodium complex catalyzes the highly enantioselective coupling of arylboronic acids, 1,3-enynes, and imines to give homoallylic sulfamates. The key step is the generation of allylrhodium(I) species by alkenyl-to-allyl 1,4-rhodium(I) migration

ISARIC-COVID-19 dataset: A Prospective, Standardized, Global Dataset of Patients Hospitalized with COVID-19

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Targeted construction of azido-bridged Ni 4

Highly preorganized pyrazolate-based dinickel(II) systems are shown to constitute suitable building blocks for the targeted assembly of azido-bridged Ni-4 complexes with rectangular arrangement of the metal ions. A set of such complexes has been prepared and structurally characterized. mu(-1), 1-Azide binding within the bimetallic sub-units is controlled by the chosen topology of the pyrazolate ligand scaffold and gives rise to the anticipated ferromagnetic intradimer coupling. Overall magnetic properties of the Ni-4 array, however, are mainly determined by the Ni-NNN-Ni torsion of the interdimer mu-1,3-azido linkages. According to the crystallographic results, these torsion angles vary over a wide range, and partial disorder of the mu-1,3-azide bridge in one of the compounds indicates high structural flexibility even in the solid state. Two of the compounds represent rare examples of molecular complexes with a Ni-NNN-Ni torsion angle of almost exactly 90 degrees. The resulting magnetic ground state (neglecting zero-field splitting) is either S = 0 or S = 4 depending on the Ni-NNN-Ni torsion, and in one case a drastic change is observed upon extrusion of lattice solvent