‘One-pot’ synthesis of 1,1-disubstituted cyclopropanes in the presence of metal complex catalysts

A ‘one-pot’ catalytic method for the synthesis of 1,1-disubstituted cyclopropanes starting from olefins, acetylenes and AlEt3 in the presence of Cp2ZrCl2, via a step involving in situ formation of aluminacyclopentanes and aluminacyclopentenes, respectively, was developed. Five-membered organoaluminium compounds obtained without preliminary isolation are transformed to cyclopropanes under the effect of Ni(acac)2 in combination with allylhalogenides in the case of aluminacyclopentanes and alkylsulphates in experiments with aluminacyclopentenes.