Investigation On The Copper-catalyzed Cyanation Of Phenyl Carbon-hydrogen Bonds And Benzyl Chloride Carbon-chlorine Bonds

The nitrile group exists extensively in many kinds of pharmaceuticals, naturalproducts, dyes and pesticides. Moreover, the nitrile group can be easily transformed intoother functional groups, so that it is important intermediate in the fine organic synthesischemistry. In view of the importance of the nitrile group, chemists continuously developnew method for the formation of the nitrile group.In this thesis, the preparation of aryl nitriles and benzyl cyanides was completedwith non-toxic K₄[Fe（CN）₆] or K₃[Fe（CN）₆] as the cyanating agents, and copper salts asthe catalyst. The main contents are as follows:1. The selective cyanation of phenyl carbon-hydrogen bonds came true usingK₃[Fe（CN）₆] as the cyanating agents, and Cu（NO₃）2·3H₂O as the catalyst. The obtainedoptimal conditions is that0.5equivalents of potassium ferricyanide,0.8equivalants ofcopper（II） nitrate and0.5equivalents of iodine in acetonitrile,35hours,180oC. Underthe optimal conditions,23alkoxybenzene substrates underwent this transformation in20%to87%yields, and were selectively cyanated at the para-position with regard to thealkoxy or benzyloxy groups. In addition, when10g anisole was used，the cynationsmoothly proceeded to give4-methoxy benzene nitriles in79%yield. Interestingly,methoxybenzene was cyanated in32%yield in the absence of potassium ferricyanide,which suggests that the nitrile group of a part of the product is possibly from the solventacetonitrile.2. Cyanation of benzyl chlorides was completed with copper salts as the catalystsand non-toxic K₄[Fe（CN）₆] as the cyanating agent. The presented method avoids the useof extremely poisonous alkali cyanides and precious palladium catalysts. We found thatbenzyl chlorides could be smoothly cynated in toluene without other reagent. Thirteenbenzyl chlorides were smoothly cyanated in up to85%yield under the optimalconditions.