chapter 7: alkyl halides Flashcards
what is an alkyl halide
reaction that will undergo substitution and elimination
is nucleophillic substituion
nucleophile replaces a halogen, wants an electrophile
what is an elimination reaction
pi bond forms when treated with a BASE, removes HX
what hybridization is a alkyl halide
Sp3 hybridized carbon
what are the two main reasons alkyl halides can undergo subsitution
- halogen on carbon withdraws electrons, creates an alpha carbon that is positive
- Halogen acts as a leaving group
what does a leaving group do, and what are some examples
- stablize the (-) charge
- conjugate bases of strong acids (Cl-, Br, I)
what is an alpha and beta carbon
- alpha = carbon directly attatched to the halogen
- beta carbon surrounding carbons that are attached to the alpha one
what mechanism focuses on beta carbons
elimination reaction
what are the steps of alkyl halide nomenclature
- identify the parent chain
- idnetify any subsitutients
- assign locants
- assemble alphabetically
example 2-bromo-3-methylhexane
how do you assign stereochemistry to alkyl halide naming
- find the configuration( either R or S) R = clockwise
S = counterclockwise - look and see if the halogen is dashed or wedged
- look to see what carbons are attached to the halogen to figure out what direction
what is a concerted mechanism vs a stepwise mechanism
- concerted is bimolecular and happens at the same time
- stepwise: is unimolecular and happens 1 at a time and involves a carbonation and a transition state
how can you determine if something is SN1 or SN2
look at the primary, tertiary, or secondary
what are the steps of a nucleophillic attack on
what are the steps of a nucleophilic attack that is concerted mechanism
- the nucleophile attacks
- loss of a leaving group happens at the same time
what are the steps of nuclephillic attack on stepwise mechanism
- loss of a leaving group then nucleophilic attack
with a carbocation being attacked by the nucleophile in a separate step
