Whalen intermediate

When the substrate is an arene, the reaction proceeds via a Whalen intermediate, as shown in Figure 19.8. The positive charge on the benzene ring in the Whalen intermediate is stabilized by electron donor atoms in the ortho and para positions. 

The Whalen intermediate in the nonpolar oxidative addition mechanism for arene substrates. 

Bone effects were observed in children (Compere 1930a Phemister 1918 Sontag 1938) and young animals (Adams 1938a, 1938b Adams and Samat 1940 Whalen et al. 1973) following acute and intermediate oral exposure to white phosphorus. Because white phosphorus-related effects were observed in growing bones, these effects were considered developmental effects, and are discussed in Section 2.2.2.6. 

The methylenedioxy derivative can act in this way as the alternative substrate of the enzyme performing the microsomal hydroxylation, but the catechol formed may also contribute to the effect (Moore and Hewlett, 1958 Metcalf et al., 1966 Casida, 1970 Casida et al., 1966 Hennessy, 1965 1969 Hennessy and Whalen, 1966 Kuwatsuka, 1970). However, this does not explain the strength and duration of synergism produced by methylenedioxyphenyl compounds. Experimental results of Franklin (1974) indicate that during oxidative metabolism these compounds form an intermediate which strongly binds to cytochrome P-450 and thereby prevents further participation of the enzyme in oxidative metabolism. 

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