nucleophilic substitution and elimination Flashcards
what is a nucleophile
region of HIGH electron density, has a lone pair of electrons and a NEGATIVE charge
what is an electrophile
region of LOW electron density, is next to an ELECTRONEGATIVE atom, has a POSITIVE charge
what makes a good leaving group
is able to stabilise a negative charge
what molecules are involved in Sn2
conjugate base nucleophile and a leaving group
what does Sn2 result in
inversion of stereochemistry
how does a nucleophile attack the molecule
180 degrees to the leaving group, into the sp3 tail of the hybridised orbital
what is the first step in Sn1
leaving group leaves
explain the first step of Sn1
the nucleophile isn’t able to attack the LG yet due to steric hinderance from the R groups
what is the transition state in Sn1 called
tertiary carbocation
when does the nucleophile attack in Sn1
attacks the tertiary carbocation
how does the nucleophile attack the tertiary carbocation in Sn1
from either side as it is sp2 and trigonal planar
what are the products of Sn1
a racemic mixture
which types of molecules undergo Sn2
primary/ secondary substrates, small/v good nucleophiles, moderate LGs
which types of molecules undergo Sn1
tertiary substrates, large/poor nucleophiles, v. good leaving groups
what is the first step of E1
leaving group leaves
