Transition‐metal‐free hydrogenation of alkenes can be carried out with simple organocalcium catalysts (20 bar H2, 20 °C). Both steps in the proposed catalytic cycle, hydride addition to the double bond and σ‐bond metathesis with H2, have been confirmed. Alkenes sensitive to polymerization are also hydrogenated in good yields.

Clean conversion of conjugated alkenes with exclusive formation of one regioisomer is achieved by using a new class of hydrosilylation catalysts based on early main‐group metals (Ca, Sr, and K). The regioselectivity can be switched to the other isomer through the choice of the metal and solvent polarity.

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The chiral β -diketimine ligand [(S)-Ph(Me)CH-N=C(Me)]CH2 was prepared by condensation of acetylacetone with the commercially available chiral building block (S)-Ph(Me)CH-NH2. Reaction of bis(o-Me2N-α-Me3Si-benzyl)calcium with this β -diketimine led to double deprotonation. Reaction of bis(o-Me2N-α-Me3Si-benzyl)calcium with the commercially available chiral bis-oxazoline (S)-Ph-BOX gave diastereopure [(S)-Ph-BOX](o-Me2N-α-Me3Si-benzyl)calcium which in solution slowly decomposed with formation of o-Me2N-α-Me3Si-toluene. The corresponding amide complex [(S)-Ph-BOX]CaN(SiMe3)2·(THF)2 is stable and the crystal structure has been determined. In solution, this heteroleptic amide is in Schlenk equilibrium with the homoleptic species [(S)-Ph-BOX]2Ca and Ca[N(SiMe3)2]2·(THF)2. This Schlenk equilibrium can be steered to the heteroleptic side. Use of the enantiopure calcium amide catalyst for the hydrosilylation of styrene with PhSiH3 or in the intramolecular hydroamination of aminoalkenes gave good product yields, but only small ee-values were observed (5 - 10%). From stoichiometric reactions of the catalyst with the substrates it is concluded that the “true” catalytically active species is mainly present as a homoleptic calcium complex, which explains the poor enantioselectivities