Cyclopropanation of alkenes with ethyl diazoacetate: Copper(I) complexes of concave 1,10-phenanthrolines as diastereoselective catalysts

Article abstract of DOI:10.1002/cber.19971300215

Concave 1,10-phenanthrolines 1a-c have been used as ligands in the copper(I)-catalyzed cyclopropanation of alkenes 2 with ethyl diazoacetate. The complexes proved to be efficient cyclopropanation catalysts and exhibited an enhanced diastereoselectivity, particularly in the reactions of cyclic alkenes 2b-d. The preferred formation of exo-cyclopropanes 3b-d can be explained by the concave shape of these catalysts. VCH Verlagsgcsellschaft mbH.