Hydrotrispyrazolylborate-copper complexes as catalysts for the styrene cyclopropanation reaction with ethyl diazoacetate under homogeneous and heterogeneous conditions

A series of complexes of general formulae TpxCu have been employed as the catalyst for the styrene cyclopropanation reaction with ethyl diazoacetate, both under homogeneous and heterogeneous conditions. Several solid supports have been tested, with silica gel being the most convenient for this transformation. A comparison of the results obtained under both conditions has shown that the catalytic pocket is affected by the support.