Novel Effect of Zinc Nitrate/Vanadyl Oxalate for Selective Catalytic Oxidation of α-Hydroxy Esters to α-Keto Esters with Molecular Oxygen: An In Situ ATR-IR Study.

ABSTRACT: Selective oxidation of α-hydroxy esters is one of the most important methods to prepare high value-added α-keto esters. An efficient catalytic system consisting of Zn(NO₃)₂/VOC₂O₄ is reported for catalytic oxidation of α-hydroxy esters with molecular oxygen. Up to 99% conversion of methyl DL-mandelate or methyl lactate could be facilely obtained with high selectivity for its corresponding α-keto ester under mild reaction conditions. Zn(NO₃)₂ exhibited higher catalytic activity in combination with VOC₂O₄ compared with Fe(NO₃)₃ and different nitric oxidative gases were detected by situ attenuated total reflection infrared (ATR-IR) spectroscopy. UV-vis and ATR-IR results indicated that coordination complex formed in Zn(NO₃)₂ in CH₃CN solution was quite different from Fe(NO₃)₃; it is proposed

SUBMITTER: Ju Y 

PROVIDER: S-EPMC6480123 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature