This chapter is concerned with reactions that lead to the formation of a new carbon-carbon bond by the replacement of X (eg, halogen, -OH, -OR, -OCOR, -NHCOR -NR 2 or NR3) from an electrophilic reagent, RCON(R’)CH(R”)X. The R’ group may be hydrogen or alkyl or an acyl group. In a few cases a sulfonyl group may replace the acyl group of the electrophilic reagent. The nucleophiles that react with these reagents fall into two broad groups: aromatic compounds and aliphatic compounds containing reactive methylene or methane groups. Methods for preparing the electrophilic reagents are included in this chapter.