Starting from santonin,the total syntheses of cytotoxic monomeric,dimeric and trimeric quainolides dehydrozalu...
Yong Qin West China School of Pharmacy,Sichuan University,Chengdu 610041 P.R.China Innovative Drug Research Centre,Chongqing University,Chongqing 401331,P.R.China
Commercially available coal-based activated carbon was treated by nitric acid with different concentrations and the resultant samples were used as catalysts for the direct hydroxylation of benzene to phenol in acetonitrile. Boehm titration, X-ray photoelectron spectroscopy, scanning electron microscope coupled with an energy dispersive X-ray microanalyzer, and Brunauer-Emmett-Teller method were used to characterize the samples. The number of carboxyl groups on the surface was found to be the main factor affecting the catalytic activity. An optimum catalytic performance with a yield of 15.7% and a selectivity of 87.2% to phenol was obtained.
Diarylimidazolium salts （3） were directly synthesized starting from lH-imidazole （1） by a one-pot strategy using diaryliodonium salts as the arylating reagents, lH-Benzimidazole and 1H-1,2,4-triazole are suitable substrates as well to form the corresponding diarylazolium salts.
