1c Flashcards
what is a heterocycle
a cycle that includes elements other than C and H
what is the importance of heterocycles
shape
rigidity
function + reactivity
describe why shape is important
heterocyclic control the spatial organisation // arrangement of atoms in moelcules
describe why rigidity is important
cycles reduce the number of conformations a molecule can take
describe why fucntion and reactivity is important
the cyclic arrangement of orbitalscontrols the electronic property of a molecule
do cyclic or acyclic molecule bind more efficiently
cyclic moleecules bind more efficinetly than cyclic ones.
bc they cant rotate their bonds,, so there a greater possibility that they will fit correctly in its binding site
where are heterocycles found in life
in pharmaceuticals
in bioactive // natural products
in chiral catalysts
in functional materials
when we think of reacting heterocycles,, what must we think of
previous reactions
enols,, aldol reactions,, immines,, enamies,, sn1, sn2 etc etc
when we dont know the final products and are reacting things together,, how do we know what will react with what
we must look at a reactants // intermediates synthetic equaivalence
synthetic equivalence: toluene with a 2 carbonyls in a row and a CF3 at the end,, what are its synthetic equivalences
we can have the enol version by deprotonating it.
or one with a triple bond between the C’s of the carbonyls.
which synthetic equivalent will be more common
the one that is easier to form
HWN:
3 membered unsat and sat
irene
irane
HWN
4 membered ring unsat and sat
ete
etane
HWN
5 membered ring unsat and sat
ole
olane
HWN 6 membered unsat and sat
ine
inane
HWN 7 membered ring
epine
epane
replacement nomenclature : when it has oxygen
oxa
replacement nomenclature: when it has sulfur
thia
replacement nomenclature: when it has nitrogen
aza
aza
nitogen
thia
sulfer
oxa
oxygen
when we assign replacement nomenclature,, how do assign them
highest precedance
we go down and up the rows from right to left of the periodic table.
so down the group,, and then up the group to its lhs
and then down the group.
its like a little snake going to the left starting hig hand going down.
OSN precedence
O >N > S
by doing the snake thing down the periodic table
a 4 membered cyclic ring with S as one of the members
S = sulfer so think of thia
cyclic so think cyclo
4 membered ring so think butane
so thia cyclo butane
think of a 5 membered ring with O and NH as 2 of the members
O has a greater prev than N so u start with oxa and put this in the 1 position
thwen u have n so think aza and u count to see what position this is in (u do this by putting O as 1 and finding the fastest route to get to N)
so u would have X- oxa - Y - aza cyclo pentane
with x and y being the position of the o and n
