Reaction of the magnesium alkenyl complex 9a with an excess of phenyl silane (PhSiH3) led to formation of the linear and cyclic silane compounds 13-14 and reformation of magnesium hydride 6. A catalytic protocol for the hydrosilylation of strained -C-C bonds was developed from these findings. Reaction of 4a-b and 7a-b with excess phenyl silane and 10 mol% of 6 showed high conversion to the respective cyclic silanes 13-18. In the case of 4b, catalytic hydrosilylation yields a mixture of E and Z stereoisomers of the product 18, with a ratio of E:Z of 1:1.1. Scheme 5 shows the proposed catalytic cycle, each step of which is supported by experimental and computational data. The stepwise process follows: