The nitro anomaly and Bronsted βnuc values in SN2 reactions on chlorine
The kinetics of chlorine transfer reactions between N-chlorosuccinimide (NCS) and four carbon nucleophiles (the conjugated bases of phenyldinitromethane, Meldrum's acid, phenylmalononitrile and phenylnitro-methane) in water were determined. A plot of log k for the SN2 reactions vs the pKa of the first three conjugated acids of the nucleophiles gave a straight line with a slope (βnuc) of 1.8. The data point for the mononitro derivative, phenylnitromethane, deviates negatively from the line by 6.7 log units. This deviation is typical of proton transfer reactions and was recently shown to occur also in SN2 reactions on bromine. Copyright
Eliad, Linoam,Hoz, Shmaryahu
p. 540 - 543
(2007/10/03)
A NEW APPROACH TO ARYLMALONONITRILES
Arylmalononitriles were prepared from the corresponding benzoyl chlorides by three reaction steps.Treatment of the starting substances with cyanotrimethylsilane in the presence of pyridine gave dicyanotrimethylsiloxymethylbenzenes, which were transformed