Markownikoff's Rule: Why Does it Happen?

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The discussion centers on understanding Markovnikov's rule, which explains the regioselectivity of electrophilic addition reactions, particularly in alkenes. Initially based on empirical observations, the rule predicts that when HX (like HCl) adds to an alkene, the hydrogen atom will bond to the carbon with more hydrogen substituents, while the halide will attach to the more substituted carbon. This preference is rationalized through the stability of carbocations formed during the reaction mechanism. A more substituted carbocation is more stable due to hyperconjugation and inductive effects, making it more favorable for nucleophiles to attack at that position. The example of 1-Methyl-2-butene illustrates this, where the addition of HCl results in the halide attaching to the more substituted carbon due to the partial positive charge created during the reaction.
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looked in books/googled for info about this...i know what it IS, but don't understand why it happens. anyone?
 
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Originally it was based on empirical evidence (it was just the product that you got from certain reactions) and was used as a predictive tool. It can be rationilized by thinking about the intermediates of a reaction mechanism. If a carbocation is formed then it will be more stable at the more substituted carbon and therefore a nucleophile would be more likely to attack at that position.
 
Well, I ain't sure of this but consider a 1-Methyl-2-butene. When HCl adds across the double bond, Cl radical will attract the electrons of the C=C towards itself creating a partial +ve charge on the C atoms. This partial positive charge is handled better by a 3rd degree C atom than the 2nd degree C atom. Thus the -ve part of the addendum will go the the C with more substituents, which is the Markonikov's rule.
 

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