Meta turn over

In 1983, Mimoun and co-workers reported that benzene can be oxidized to phenol stoichiometrically with hydrogen peroxide in 56% yield, using peroxo-vana-dium complex 1 (Eq. 2) [20]. Oxidation of toluene gave a mixture of ortho-, meta-and para-cresols with only traces of benzaldehyde. The catalytic version of the reaction was described by Shul pin[21] and Conte [22]. In both cases, conversion of benzene was low (0.3-2%) and catalyst turned over 200 and 25 times, respectively. The reaction is thought to proceed through a radical chain mechanism with an electrophilic oxygen-centered and vanadium-bound radical species [23]. 

Four meta-analyses of the more complete and reliable data contained in both cross-sectional and/or longitudinal evaluations have been published. Needleman and Gatsonis (1990) included seven PbB and five dentine Pb studies, which in turn were from studies generated over 17 years, 1972—1989. The levels of statistical significance for the exposure— neurobehavioral decrement relationship for PbB and dentine Pb as the dose measure were estimated as joint p-values. They found very low joint p-values. 

---