The Oxidative Reaction Mediated By NHPI/O₂ And TBHP

NHPI?N-Hydroxyphthalimide?/O₂ system is widely used in organic synthesis,such as in the oxidation of hydrocarbon,alcohols?thiol?,amine,etc.But it is less reported about the coupling reaction of two nonfunctional substrates with this system via C-C and C-N bond formation.Based on these,the coupling reaction between 1,3-diarylallylic and alcohols promoted by NHPI/O₂ in CH2C1CH2Cl with CuBr/NiCl2 as a catalyst was firstly studied.As desired,twelve allylic compounds with moderate yields are obtained and it provides a feasible method for the synthesis of the corresponding compounds.We speculate that the allylic alcohol intermediates is probably formed in the reaction between 1,3-diarylallylic and alcohols by NHPI/O₂.Then the coupling reaction between 1,3-diaryl-1-propene and thiobenzamide with the same system is tried.But we fail to obtain the corresponding coupling products.According to the CuBr/TBHP system applied in oxidation reaction recently,the oxidative coupling of thiobenzamide was performed.Unexpectedly,the oxidative desulfurization products of thiobenzamides were obtained.In the experiment,thioamides containing alkyl or aryl on the nitrogen undergo desulfurization and give amides.Thioamides not containing substituent on the nitrogen give 1,2,4-thiadiazoles.Seventeen products were obtained with moderate to good yields.