The copper(I) complex (FcNN)Cu(OTf) (1; FcNN = N,N'-ethylenebis[(ferro
cenylmethylene)amine] catalyzes reactions of ethyl diazoacetate with a
lkenes to form cyclopropanes in high yield. The same complex also cata
lyzes nitrene transfer from PhI=NTs to alkenes to produce aziridines i
n high yield.