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The effect of the tert-butyl group on the progress of a chemical reaction is called the Thorpe–Ingold effect illustrated in the Diels-Alder reaction below. Compared to a hydrogen substituent, the tert-butyl substituent accelerates the reaction rate by a factor of 240. [2] tert-Butyl effect. The tert-butyl effect is an example of steric hindrance.
tert-Butyl bromide (also referred to as 2-bromo-2-methylpropane) is an organic compound with the formula Me 3 CBr (Me = methyl). The molecule features a tert-butyl group attached to a bromide substituent. This organobromine compound is used as a standard reagent in synthetic organic chemistry. It is a colorless liquid.
The steric effect of tri-(tert-butyl)amine makes electrophilic reactions, like forming the tetraalkyl ammonium cation, difficult. It is difficult for electrophiles to get close enough to allow attack by the lone pair of the nitrogen (nitrogen is shown in blue)
The reaction is facilitated by electron-releasing substituents (the inductive effect) and in general the observed order (with decreasing reactivity) is tert-butyl > isopropyl > ethyl > methyl. The observed order in this particular reaction however was methyl > ethyl> isopropyl > tert-butyl.
For example, a change of reaction medium from hexane to water increases the rate of tert-Butyl chloride (t-BuCl) heterolysis by 14 orders of magnitude. [5] This is caused by very strong solvation of the transition state. The main factors that affect heterolysis rates are mainly the solvent's polarity and electrophilic as well as its ionizing power.
An example of a reaction taking place with an S N 1 reaction mechanism is the hydrolysis of tert-butyl bromide forming tert-butanol: This S N 1 reaction takes place in three steps: Formation of a tert-butyl carbocation by separation of a leaving group (a bromide anion) from the carbon atom: this step is slow. [5] Recombination of carbocation ...
An electron donating group (EDG) or electron releasing group (ERG, Z in structural formulas) is an atom or functional group that donates some of its electron density into a conjugated π system via resonance (mesomerism) or inductive effects (or induction)—called +M or +I effects, respectively—thus making the π system more nucleophilic.
It is a colorless liquid with a pleasant odor. Because the carbon atom connected to the bromine is connected to two other carbons the molecule is referred to as a secondary alkyl halide. 2-Bromobutane is chiral and thus can be obtained as either of two enantiomers designated as (R)-(−)-2-bromobutane and (S)-(+)-2-bromobutane.