The Azametallacyclopropane Ca(η²-Ph₂CNPh)(hmpa)₃:  A Calcium Alternative to a Versatile Ytterbium(II) Catalyst

The azametallacyclopropane complex Ca(η²-Ph₂CNPh)(hmpa)₃ (2-Ca) can be conveniently obtained in crystalline purity via a one-pot procedure (yield 48%). The catalytic activities and selectivities of 2-Ca and its Yb(II) analogue 2-Yb have been found to be comparable in a variety of reactions; therefore, 2-Ca could be a cheap substitute for the extensively studied Yb(II) catalyst.