Activating groups Substituents that, when

Reactive dyes contain substituent that, when activated, react with the -OH groups of cellulose (i.e., cotton) or with -NH2 and -SH groups of protein fibers (i.e., wool) forming covalent bonds, making them among the most permanent of dyes. 

Activating substituent (Sections 12 10 and 12 12) A group that when present in place of a hydrogen causes a particular reaction to occur faster Term is most often applied to sub stituents that increase the rate of electrophilic aromatic sub stitution... 

The entrance of a third or fourth substituent can be predicted by Beilstein s rule. If a substituent Z- enters into a compound C H XY, both X and Y exert an influence, but the group with the predominant influence directs Z- to the position it will occupy. Since all meta-directing groups are deactivating, it follows that ortho—para activating groups predominate when one of them is present on the benzene ring. 

More than twenty years ago, Nesmeyanov s group showed that chlorine can be substituted by a variety of nucleophiles in FeCp(r 6-PhCl)+ [83, 84]. Indeed the chlorine substituent in the chlorobenzene (even) ligand is 1000 times more reactive than when it is located on the cyclopentadienyl (odd) ligand [85]. The FeCp+ is a good withdrawing group which is equivalent to two nitro groups in terms of activation. The reactions proceed under ambient conditions with primary or secondary amines and have been extended to other substituted chloroarene complexes [86, 87] Eq. (22), Table 2. 

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