Highly Effective Alkaline Earth Catalysts for the Sterically Governed Hydrophosphonylation of Aldehydes and Nonactivated Ketones.

Down-to-earth catalysis: Heteroleptic and, more interestingly, homoleptic complexes of the large alkaline earth metals (calcium, strontium, and barium) constitute remarkably efficient catalysts for hydrophosphonylation reactions of aldehydes and nonactivated ketones (see scheme). Perfect chemoselectivities and unprecedented turnover frequencies (TOFs) are reported.