Efficient and selective catalysis for hydrogenation and hydrosilation of alkenes and alkynes with PNP complexes of scandium and yttrium.

Title Efficient and selective catalysis for hydrogenation and hydrosilation of alkenes and alkynes with PNP complexes of scandium and yttrium.
Authors D.S. Levine; D. Tilley; R.A. Andersen
Journal Chem Commun (Camb)
DOI 10.1039/c7cc06417a
Abstract

Scandium and yttrium congeneric complexes, supported by a monoanionic PNP ligand, were studied as catalysts for alkene hydrogenation and hydrosilation, and alkyne semihydrogenation and semihydrosilation. The yttrium congener was found to be much more active in all cases, but this greater activity is accompanied by more rapid catalyst decomposition and therefore higher total yields for some of the reactions with the scandium catalyst. Calculations indicate that the reactions may proceed via ?-bond metathesis of the alkyl complexes to form metal hydride intermediates into which alkenes/alkynes insert.

Citation D.S. Levine; D. Tilley; R.A. Andersen.Efficient and selective catalysis for hydrogenation and hydrosilation of alkenes and alkynes with PNP complexes of scandium and yttrium.. Chem Commun (Camb). 2017;53(87):1188111884. doi:10.1039/c7cc06417a

Related Elements

Scandium

See more Scandium products. Scandium (atomic symbol: Sc, atomic number: 21) is a Block D, Group 3, Period 4 element with an atomic weight of 44.955912. The number of electrons in each of Scandium's shells is [2, 8, 9, 2] and its electron configuration is [Ar] 3d1 4s2. Scandium Bohr Model The scandium atom has a radius of 162 pm and a Van der Waals radius of 216 pm.Scandium was predicted by Dmitri Mendeleev in 1871 and actually discovered and isolated by Lars Nilson in 1879. One of the transition metals, scandium has a silvery-white appearance in its elemental form which oxidizes to yellow or pinkish upon contact with air. Elemental ScandiumIt is occasionally included in the classification of the rare earth elements. Scandium is found in concentrated amounts in the minerals euxenite, gadolinite and thortveitite however, due to the difficulties in the preparation of metallic scandium, global trade of the pure metal is very limited. The origin of the name scandium comes from the Latin word 'scandia' meaning Scandinavia.

Yttrium

See more Yttrium products. Yttrium (atomic symbol: Y, atomic number: 39) is a Block D, Group 3, Period 5 element with an atomic weight of 88.90585. Yttrium Bohr ModelThe number of electrons in each of yttrium's shells is [2, 8, 18, 9, 2] and its electron configuration is [Kr] 4d1 5s2. The yttrium atom has a radius of 180 pm and a Van der Waals radius of 219 pm. Yttrium was discovered by Johann Gadolin in 1794 and first isolated by Carl Gustav Mosander in 1840. In its elemental form, Yttrium has a silvery white metallic appearance. Yttrium has the highest thermodynamic affinity for oxygen of any element. Elemental YttriumYttrium is not found in nature as a free element and is almost always found combined with the lanthanides in rare earth minerals. While not part of the rare earth series, it resembles the heavy rare earths which are sometimes referred to as the "yttrics" for this reason. Another unique characteristic derives from its ability to form crystals with useful properties. The name yttrium originated from a Swedish village near Vaxholm called Yttbery where it was discovered.

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