A stable well-defined copper hydride cluster consolidated with hemilabile phosphines

Copper hydrides are very useful in hydrogenation reactions. We report a stable Stryker-type copper hydride reagent protected by hemilabile phosphines: [Cu8H6(dppy)6](OTf)2 (Cu8-H, dppy = diphenylphosphino-2-pyridine). The metal core of this cluster has a bicapped octahedral configuration, and the copper-bound hydrides each triply bridges over a triangular face of the octahedron. This cluster is attractive due to its facile preparation and excellent stability under ambient conditions. The comparable activity and selectivity both in the stoichiometric and catalytic reactions make Cu8-H a promising alternative to Stryker's reagent.