Nickel-Catalyzed, Regio- and Stereoselective Hydroalkynylation of Methylenecyclopropanes with Retention of the Cyclopropane Ring, Leading to the Synthesis of 1-Methyl-1-Alkynylcyclopropanes

Abstract

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.