Mg2+-Promoted P-O vs. S-O Bond Cleavage in the Alcoholyses of Phenyl Phosphatosulfate

Article abstract of DOI:10.1246/bcsj.66.2931

In order to obtain insight into the selectivity of Mg²⁺ at the site of bond cleavage of P-O and S-O of the P-O-S linkage, metal ion-promoted alcoholyses of phenyl phosphatosulfate were studied.Mg²⁺ quantitatively promoted P-O bond cleavage in the methanolysis, but mixed cleavage of the P-O bond, which occurred partly due to hydrolysis by trace water and the S-O bond in the reaction of ethanol, 1- or 2-propanol.The ratio of the S-O bond cleavage against the mixed cleavage increased in a order EtOH (11.5percent) < n-PrOH (13.3percent) < i-PrOH (29.0percent).On the other hand, Ca²⁺ and Zn²⁺ promoted selective P-O and S-O bond cleavage, respectively, in the reaction of 2-propanol as well as methanolysis.The medium-dependent change in the selectivity of Mg²⁺ at the site of bond cleavage was discussed.