1620164-47-7Relevant academic research and scientific papers
Stereochemistry and mechanism of enzymatic and non-enzymatic hydrolysis of benzylic sec-sulfate esters
Toesch, Michael,Schober, Markus,Breinbauer, Rolf,Faber, Kurt
, p. 3930 - 3934 (2014)
The substrate scope of inverting alkylsulfatase Pisa1 was extended towards benzylic sec-sulfate esters by suppression of competing non-enzymatic autohydrolysis by addition of dimethyl sulfoxide as co-solvent. Detailed investigation of the mechanism of autohydrolysis in 18O-labeled buffer by using an enantiopure sec-benzylic sulfate ester as substrate revealed that from the three possible pathways (i) inverting SN2-type nucleophilic attack of [OH-] at the benzylic carbon represents the major pathway, whereas (ii) SN1-type formation of a planar benzylic carbenium ion leading to racemization was a minor event, and (iii) Retaining SN2-type nucleophilic attack at sulfur took place at the limits of detection. The data obtained are interpreted by analysis of Hammett constants of meta substituents. The enzymatic hydrolysis of benzylic sec-sulfate esters by alkylsulfatase Pisa1 proceeded with clean inversion of configuration and with excellent stereoselectivities when the competing non-enzymatic hydrolysis was suppressed by addition of dimethyl sulfoxide as co-solvent. Copyright
