Enantioselective aerobic oxidation of olefins by magnetite nanoparticles at room temperature: a chiral carboxylic acid strategy

Abstract

Asymmetric oxidations of organic compounds are limited in their synthetic scope and by practical factors, such as the use of complex catalyst synthesis. A simple and cheap nanostructured catalyst system comprising magnetite nanoparticles stabilized by L-(+)-tartaric acid (Fe3O4/tart-NPs) were successfully synthesized in diethylene glycol. The catalyst was characterized by FT-IR, TGA, ICP-AES, XRPD, SEM and dynamic light scattering (DLS). Catalytic activity of Fe3O4/tart-NPs dispersion in acetonitrile in the presence of isobutyralhyde was studied in selective aerobic oxidation of olefins to form asymmetric epoxide, an important intermediate for the synthesis of biologically active compounds. In addition, the magnetically recoverable nanocatalyst Fe3O4/tart-NPs can be conveniently separated and recovered from the reaction system by applying an external magnetic field and reused for five cycles without the loss of activity after each cycle. These results demonstrate that the heterogeneous nanocatalysts possess potential applications for green and sustainable development. As synthesized nanoparticles of Fe3O4/tart-NPs are a chip and easy to synthesize asymmetric catalyst which were prepared without involvement of difficult and cumbersome procedure for the synthesis of complicated asymmetric ligands. Possible reaction mechanisms were outlined.

High performance of ultrasonic-assisted synthesis of two spherical polymers for enantioselective catalysis

“…Some factors are responsible for the broad characteristic band at 3441 cm −1 such as: OH, stretching vibration owing to the Fe–OH groups, the carboxylic groups of tartaric acid, and adsorbed water ( Fig. 3 b) [77] . Electron microscopy investigations of the prepared samples (CMNPs/1,4-Zbtb) by three synthetic methods were also performed, extensively.…”

Recent Advances in Iron Catalyzed Oxidation Reactions of Organic Compounds

“…Hosseini‐Monfared reported the enantioselective aerobic epoxidation of olefins by magnetite nanoparticles at room temperature . The catalyst system consists of magnetite nanoparticles stabilized by L‐(+)‐tartaric acid (Fe 3 O 4 /tart‐NPs).…”

Polymeric ionic liquid material‐anchored Mn–porphyrin anion: Heterogeneous catalyst for aerobic oxidation of olefins

“…The great mismatch of [Mn(TPPS)(OAc)] and APTMACl regarding ionic nature, structural skeleton and miscibility did overcome the limitation of mass transfer, favouring catalytic activity . Also, the polarity, low coordinating ability and aprotic nature of acetonitrile are play the main role in improving the activity of the catalyst . Besides, it seems that polar solvents have a significant effect on the activation of intermediate species in manganese–porphyrin compounds and increase their catalytic activity .…”

“…[51] Also, the polarity, low coordinating ability and aprotic nature of acetonitrile are play the main role in improving the activity of the catalyst. [52] Besides, it seems that polar solvents have a significant effect on the activation of intermediate species in manganese-porphyrin compounds and increase their catalytic activity. [53] In fact, organic polar solvents, such as CH 3 CN, could affect access of substrate to active sites by increasing the solubility and diffusion of reactants in ILs.…”