A family of five- and six-coordinate chiral-at-metal ruthenium complexes has been examined as catalysts in the asymmetric cyclopropanation reaction of styrene with ethyl diazoacetate. With complexes 5 and 6, good cis-diastereoselectivity and enantioselectivity up to 74 % were observed. (c) 2005 Elsevier B.V All rights reserved.