Nitrotoluene Lab Report

799 Words2 Pages

1. The major goal of this paper is to examine the electronic effects of how substituent groups impact the hydroboration of the substituted styrene molecules. The scientists focused mainly on understanding the positioning in which the boron-hydrogen moiety was added to the carbon-carbon double bond.
2. The purpose of the experiments reported in Table 1 was to determine the reproducibility of the α and β alcohol distribution as a result of the hydroboration of styrene. This was achieved through manipulating the variations of the hydride/styrene ratios. The results indicated a 19:81 α to β ratio that showed consistency with the reported 20:80 ratio. The results in Table 1 deduced that there was no significant change through the distribution of …show more content…

The presence of ethylbenzene complicated the analysis of results because the increased appearance of ethylbenzenes as a product of o- and p-trifluromethylstyrene and m-nitrostyrene was inversely related with a decrease in the yield of α alcohol. The author concluded that the product of ethylbenzene was due to competing reactions taking place.

4. The α hydrogen in p-nitrotoluene would be more acidic than the α hydrogen in m-nitrotoluene because the conjugate base of p-nitrotoluene has more resonance allowing for a greater delocalization of the charge and more stability. The more stable a molecule is the faster it will react when compared to a less stable molecule and thus the α hydrogen in p-nitrotoluene is more likely to donate its …show more content…

With increased amounts of boron distribution in the α position would come from a greater desire for the transition state III.

The p-CF isomer has the highest α-boron distribution due to the highly electronegative CF substituent. The tri-fluoro group connected to the carbon would stabilize the partial negative of the α carbon in transition state III through induction. Fluorine is more electronegative than chlorine, so fluorine would have a greater inductive force.

The p-CH3O isomer would favor transition state II. This is because the partial positive of α carbon in transition state II could be stabilized through resonance.

The styrene molecule H would favor transition state II because the molecule is stabilized through hyperconjugation and resonance. Transition state III is not preferred because the partial positive would have less hyperconjugation and the boron would cause steric strain.

The p-Cl isomer would have a higher α boron distribution. The chlorine acts as an electron withdrawing substituent. This would stabilize the partial negative on the α carbon in transition state

More about Nitrotoluene Lab Report

Open Document