When complexed by selected ligands in either the BIPHEP or the SEGPHOS series, CuH is an extremely reactive catalyst capable of effecting asymmetric hydrosilylations of aromatic ketones at temperatures between -50 and -78 degrees C. Inexpensive silanes serve as stoichiometric sources of hydride. Substrate-to-ligand ratios exceeding 100000:1 have been documented. The level of induction is usually in the >90% ee category. The nature of the reagent has been investigated using spectroscopic and chemical means, although its composition remains unclear.
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