Sonochemical synthesis of lithium fluoride nano cubic as an active and simple catalyst for thia-Michael addition process: synthesis and structural characterization of β-aryl-β-mercapto ketones

Abstract

LiF nano cubic, with an average particle size of 21.6 nm, was synthesized sonochemically, using tetrabutylammonium fluoride as the fluoride source and characterized by SEM-EDX and XRD. This was applied, as a heterogeneous nano-catalyst, to synthesize some β-aryl-β-mercapto ketone derivatives via thia-Michael addition reactions with excellent yields at room temperature. In this catalytic system, the products of undesirable side reactions resulting from 1,2-addition, polymerization, bis-addition and oxidative coupling of thiols were not observed. The products were characterized by elemental analysis, IR, NMR and mass, and also single crystal X-ray determination for 3-(4-chlorophenylthio)-1,3-diphenylpropan-1-one, 1-phenyl-3-(phenylthio)-3-p-tolylpropan-1-one, 3-(p-tolylthio)-1-phenyl-3-p-tolylpropan-1-one and 3-(4-chlorophenylthio)-1-phenyl-3-p-tolylpropan-1-one. Following the recent search on the CSD, it is found that there is no report on the structure determination of [R1]C[H][CH2C(O)R2][S-Ar] β-aryl-β-mercapto ketones with the S-C6H5, S-C6H4-p-CH3 and S-C6H4-p-Cl segments (as S-Ar).