The replacement of bromo and methoxylgroups of fluorenone, N-(9-fluorenylidene)aniline, and α-benzylideneacetophenone with ArSMgBr(S), ArNHMgBr(NH), and ArN(MgBr)2(N) were examined. The distribution of products obtained in the reactions with the reagents including ArMgBr(C) and ArOMgBr(O) were explained in terms of relative electron-donating abilities of reagents: C>S>NH>N>O.