Chemical Science,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Jan. 1, 2024
The
previously
unreported
combination
of
nucleophilic
phosphine
catalysis
and
energy
transfer
allows
for
the
rapid
construction
structurally
distinct
2-oxabicyclo[2.1.1]hexanes
(2-oxa-BCH)
from
readily
available
building
blocks
with
high
atom
economy.
Previous
multistep
routes
to
these
important
phenyl
ring
bioisosteres
have
largely
depended
on
use
bespoke
strain-release
agents
or
multiple
post-functionalisation
reactions
access
structural
diversity
scaffold.
In
contrast,
this
cascade
reaction
medicinal
chemist
exploit
breadth
commercial
allyl
alcohols
synthesise
systematically
diverse
2-oxa-BCH
architectures.
Using
a
polar
radical
disconnections
in
same
flask,
every
position
scaffold
can
be
substituted
useful
functional
handles
such
as
protected
amines,
esters
alcohols,
well
arenes
alkyl
groups.
Cyclic
even
employed
yield
single
diastereomers
sp
Synthesis,
Journal Year:
2024,
Volume and Issue:
56(20), P. 3119 - 3130
Published: May 29, 2024
Abstract
Breaking
aromaticity
by
inserting
additional
atoms
within
the
skeleton
of
heteroaromatic
rings
has
gained
significant
attention
over
years.
As
part
emerging
concept
‘skeletal
editing’,
this
short
review
retraces
recent
progress
made
on
dearomative
enlargement
reactions
both
five-
and
six-membered
heterocycles.
1
Introduction
2
Dearomative
Enlargement
Five-Membered
Rings
2.1
Pyrroles,
Furans,
Thiophenes
Their
Fused
Analogues
2.2
Pyrazoles,
Isoxazoles,
Isothiazoles
3
Six-Membered
4
Conclusion
Perspectives
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 4, 2024
The
reduction
of
abundant
benzene
rings
to
scarce
C(sp3)-rich
motifs
is
invaluable
for
drug
design,
as
C(sp3)
content
known
correlate
with
clinical
success.
Cyclohexenes
are
attractive
targets,
they
can
be
rapidly
elaborated
into
large
product
libraries
and
stable
against
rearomatization.
However,
partial
reactions
benzenes
cyclohexenes
rare
have
a
very
narrow
scope.
Herein
we
report
broadly
applicable
method
that
converts
electron-poor
tolerates
Lewis-basic
functional
groups
such
triazoles
thioethers
well
reducible
cyanides,
alkynes,
sulfones.
reaction
utilizes
an
organic
donor
induces
mild
arene
by
preassociation
photoexcitable
electron
donor–acceptor
(EDA)
complex
isomerization
redox-inert
1,4-cyclohexadienes
1,3-cyclohexadienes
without
strong
base
in
its
oxidized
thioquinone
methide
form.
Abstract
In
this
work,
we
extend
the
one‐pot
protocol
to
synthesize
1,2‐diazepines
from
commercially
available
and
cheap
starting
materials.
Capitalizing
on
isocyanate
derivatives
as
activating
agents,
photochemical
skeletal
enlargement
occurs,
while
preserving
key
functional
groups
embedded
in
more
than
30
substrates.
We
also
demonstrated
that
isocyanates
can
be
generated
situ
exploiting
wealth
of
methods
bench
stable
resources.
Compare
previous
strategies,
use
these
precursors
prevents
presence
deleterious
HCl
traces
system,
thus
enabling
synthesis
high
yields
over
up
5
sequential
steps.
Chemical Science,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Jan. 1, 2024
The
previously
unreported
combination
of
nucleophilic
phosphine
catalysis
and
energy
transfer
allows
for
the
rapid
construction
structurally
distinct
2-oxabicyclo[2.1.1]hexanes
(2-oxa-BCH)
from
readily
available
building
blocks
with
high
atom
economy.
Previous
multistep
routes
to
these
important
phenyl
ring
bioisosteres
have
largely
depended
on
use
bespoke
strain-release
agents
or
multiple
post-functionalisation
reactions
access
structural
diversity
scaffold.
In
contrast,
this
cascade
reaction
medicinal
chemist
exploit
breadth
commercial
allyl
alcohols
synthesise
systematically
diverse
2-oxa-BCH
architectures.
Using
a
polar
radical
disconnections
in
same
flask,
every
position
scaffold
can
be
substituted
useful
functional
handles
such
as
protected
amines,
esters
alcohols,
well
arenes
alkyl
groups.
Cyclic
even
employed
yield
single
diastereomers
sp
