Nickel-catalyzed, regio- and stereoselective hydroalkynylation of methylenecyclopropanes with retention of the cyclopropane ring, leading to the synthesis of 1-methyl-1-alkynylcyclopropanes.

The C-H bond of triisopropylsilylacetylene adds to the C=C bond of substituted methylenecyclopropanes in a regio- and stereoselective manner at room temperature in the presence of nickel catalysts bearing PMePh(2). The C-C bond formation takes place at the internal sp(2) carbon atom with high regioselectivity from the pi face opposite the substituents located in the three-membered rings.