Term
Alkyl Halides are electrophile or nucleophiles? |
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Definition
Electrophiles that involve polar reactions with nucleophiles and bases |
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Term
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Definition
| the relationship between the rate at which a reaction occurs and the concentration of reactancts |
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Term
What are second order reactions and what is the formula? |
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Definition
Reactions which the rate is linearly dependent on the concentrations of two species
=k x [RX] x [-OH]
k=rate constant
RX=CH3Br concentration in molarity
OH=OH concentration in molarity |
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Term
What does Sn2 reaction stand for?
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Definition
*Short for Substitution, Nucleophilic, Bimolecular (2 molecules take place in the step where kinetics are measured [nucleophile and alkyl halide])
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Term
How does Nucleophile attack substrate in Sn2 Reaction? What is the outcome? |
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Definition
*This takes place in a single step (no intermediate)
*Nucleophile attacks from opposite side the halide is on (180 degrees)
*When Nucleophile electrons attaches is forces out the halide causing a transition state where the negative charge is delocalized
[image]<--Transition state
*The back side approach causes the substrate to invert
(R would turn into an S vice versa)
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Term
In Sn2 Reactions, do they work faster with more or less substrates attached to the carbon being attacked?? |
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Definition
the less substrates the faster the reaction
***Vinylic and Aryl Halides CAN NOT react in Sn2 Reactions |
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Term
In Sn2 Reactions.....
A Negative nucleophile = a ______ Product |
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Definition
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Term
In Sn2 Reactions...
A Nuetral nucleophile = a _______ product |
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Definition
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| Nucleophilicity usually increases and you go _______ a column of the periodic table |
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Definition
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Term
Negative charged nucleophiles are more or less reactive than neutral ones? |
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Definition
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Term
| What does Sn1 reaction mean? What is its rate equation? |
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Definition
stands for subtitution nucleophile unimolecular
*It is a first order process which means the concentration of the nucleophole does not appear in the rate equation
=k x [RX] |
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Term
What is the highest transition state of energy in a Sn1 rxn called? |
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Definition
Rate limiting step or rate determining step |
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Term
| How does an Sn1 reaction occur? |
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Definition
| the leaving group leaves first, a carbocation intermediate is formed, the the nucleophile approaches leading to a racemic mixture of product enantiomers. |
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Term
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Definition
| means next to a aromatic ring |
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Term
| Sn1 reactions prefer tertiary or secondary substrates? |
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Definition
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Term
What solvents are preferred in Sn1 reactions? |
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Definition
polar protic solvents
(alcohols, waters and so on)
*affects on rxn due to stabilization or destabilization of transtion state |
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Term
What happens during elimination reactions of alkyl halides? |
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Definition
| Hydrogen halide is eliminated from alkyl halide to form an alkene |
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Term
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Definition
According to Zaitsev’s rule, during elimination of HX from an alkyl halide, the more highly substituted alkene product predominates. |
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Term
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Definition
stands for : elimination bimolecular
*alkyl halide treated with a STRONG base [-OH or RO-]
*there is no intermediate, acts like Sn2 and perfers antiperplanar (all 4 reacting atoms lie in the same place but H and X are anti each other)
*antiperplanar preferred because of Staggered realtion ship |
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Term
What is the rate equation of E2 reaction? |
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Definition
Rate= k [base][substrate] |
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| What is the E1 rxn and what the the rate formula |
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Definition
· **Elimination of HX occurs by E1 mechanism if the alkyl halide is treated with a weak base or a non-basic nucleophile.
· *** An intermediate carbocation is generated in the process.
***rate = k[substrate]
str
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Term
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Definition
· Takes place through a carbanion intermediate
· Reaction common in substrates with poor leaving group, e.g. –OH, two carbons away from a carbonyl group. |
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