Chiral calciumcatalysts for asymmetric hydroamination/cyclisation

Calcium complexes supported by chiral 1,2-diamines have been shown to be efficient catalysts for the asymmetric hydroamination of amino-olefin substrates; the calcium complexes [Ca(NN(R)){N(SiMe(3))(2)}(THF)] (R = (t)Bu, (i)Pr, Ph, 4-C(6)H(4)F) give enantioselectivities of up to 26% which marks a significant increase based upon literature precedence. The structure of [Ca(NN(Ph)){N(SiMe(3))(2)}(py)] has been computed with density functional methods.