title: Theoretical study on the alkaline hydrolysis of methyl thioacetate in aqueous solution.
abstract: A base-catalyzed hydrolysis reaction of thiolester has been studied in both gas and solution phases using two ab initio quantum mechanics calculations such as Gaussian09 and CPMD. The free-energy surface along the reaction path is also constructed using a configuration sampling technique, namely, the metadynamics method. While there are two different reaction paths obtained for the potential profile of the base-catalyzed hydrolysis reaction for thiolester in the gas phase, a triple-well reaction path is computed for the reaction in the solution phase by two quantum mechanics calculations. Unlike the S(N)2 mechanism (a concerted mechanism) found for the gas-phase reaction, a nucleophilic attack from the hydroxide ion on the carbonyl carbon to yield a tetrahedral intermediate (a stepwise mechanism) is observed for the solution-phase reaction. Moreover, the energy profiles computed by these two theoretical calculations are found to be very comparable with those determined experimentally.
authors: Institute of Molecular Medicine & Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC.
authors: Chein-Wei
authors: CW
authors: Fu
authors: Thy-Hou
authors: TH
authors: Lin
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000468:Alkalies / Q000737:chemistry*; D006868:Hydrolysis; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D012996:Solutions; D014867:Water / Q000737:chemistry
chemical_list: D000085:Acetates; D000468:Alkalies; D012996:Solutions; D014867:Water; C026500:methyl thioacetate