Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(14)
Published: Jan. 5, 2024
Bicycloalkanes,
cubanes
and
their
structural
analogues
have
emerged
as
bioisosteres
of
(hetero)arenes.
To
meet
increasing
demand,
the
chemical
community
has
developed
a
plethora
novel
synthetic
methods.
In
this
review,
we
assess
progress
made
in
field
light-driven
construction
functionalization
such
relevant
molecules.
We
focused
on
diverse
targets,
well
reaction
processes
giving
access
to:
(i)
[1.1.1]-bicyclopentanes
(BCPs);
(ii)
[2.2.1]-bicyclohexanes
(BCHs);
(iii)
[3.1.1]-bicycloheptanes
(BCHeps);
(iv)
cubanes;
other
structurally
related
scaffolds.
Finally,
future
perspectives
dealing
with
identification
manifolds
to
new
functionalized
bioisosteric
units
are
discussed.
Chemical Science,
Journal Year:
2023,
Volume and Issue:
14(36), P. 9885 - 9891
Published: Jan. 1, 2023
Crossed
[2
+
2]
cycloaddition
yields
bicyclo[2.1.1]hexanes
with
11
different
substitution
patterns.
ortho
-,
meta
-
and
polysubstituted
benzene
bioisosteres,
structures
substituent
patterns
that
go
beyond
aromatic
chemical
space
can
be
prepared.
Chemical Science,
Journal Year:
2023,
Volume and Issue:
14(48), P. 14092 - 14099
Published: Jan. 1, 2023
1,2-Disubstituted
bicyclo[2.1.1]hexanes
have
been
synthesized,
characterized,
and
biologically
validated
as
saturated
bioisosteres
of
the
ortho
-substituted
benzene
ring.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(13)
Published: Jan. 30, 2024
Abstract
Herein,
we
have
synthesized
multifunctionalized
2‐oxa‐3‐azabicyclo[3.1.1]heptanes,
which
are
considered
potential
bioisosteres
for
meta
‐substituted
arenes,
through
Eu(OTf)
3
‐catalyzed
formal
dipolar
[4π+2σ]
cycloaddition
of
bicyclo[1.1.0]butanes
with
nitrones.
This
methodology
represents
the
initial
instance
fabricating
bicyclo[3.1.1]heptanes
adorned
multiple
heteroatoms.
The
protocol
exhibits
both
mild
reaction
conditions
and
a
good
tolerance
various
functional
groups.
Computational
density
theory
calculations
support
that
mechanism
likely
involves
nucleophilic
addition
nitrones
to
bicyclo[1.1.0]butanes,
succeeded
by
an
intramolecular
cyclization.
synthetic
utility
this
novel
has
been
demonstrated
in
concise
synthesis
analogue
Rupatadine.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(29), P. 19621 - 19628
Published: May 13, 2024
For
nearly
60
years,
significant
research
efforts
have
been
focused
on
developing
strategies
for
the
cycloaddition
of
bicyclobutanes
(BCBs).
However,
higher-order
and
catalytic
asymmetric
BCBs
long-standing
formidable
challenges.
Here,
we
report
Pd-catalyzed
ligand-controlled,
tunable
cycloadditions
divergent
synthesis
bridged
bicyclic
frameworks.
The
dppb
ligand
facilitates
formal
(5+3)
vinyl
oxiranes,
yielding
valuable
eight-membered
ethers
with
scaffolds
in
100%
regioselectivity.
Cy-DPEphos
promotes
selective
hetero-[2σ+2σ]
to
access
pharmacologically
important
2-oxabicyclo[3.1.1]heptane
(O-BCHeps).
Furthermore,
corresponding
O-BCHeps
94–99%
ee
has
achieved
using
chiral
(S)-DTBM-Segphos,
representing
first
cross-dimerization
two
strained
rings.
obtained
are
promising
bioisosteres
ortho-substituted
benzenes.
Chemical Science,
Journal Year:
2023,
Volume and Issue:
14(36), P. 9696 - 9703
Published: Jan. 1, 2023
Ring-opening
of
bicyclo[1.1.0]butanes
(BCBs)
is
emerging
as
a
powerful
strategy
for
1,3-difunctionalized
cyclobutane
synthesis.
However,
reported
radical
strain-release
reactions
are
typically
plagued
with
diastereoselectivity
issues.
Herein,
an
atom-economic
protocol
the
highly
chemo-
and
diastereoselective
polar
ring-opening
BCBs
hydroxyarenes
catalyzed
by
π-acid
catalyst
AgBF4
has
been
developed.
The
use
readily
available
starting
materials,
low
loading,
high
selectivity
(up
to
>98
:
2
d.r.),
broad
substrate
scope,
ease
scale-up,
versatile
functionalizations
products
make
this
approach
very
attractive
synthesis
1,1,3-trisubstituted
cyclobutanes.
Moreover,
control
experiments
theoretical
calculations
were
performed
illustrate
reaction
mechanism
selectivity.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(21)
Published: March 5, 2024
Abstract
Synthesis
of
bicyclic
scaffolds
has
emerged
as
an
important
research
topic
in
modern
drug
development
because
they
can
serve
saturated
bioisosters
to
enhance
the
physicochemical
properties
and
metabolic
profiles
candidates.
Here
we
report
a
remarkably
simple
silver‐enabled
strategy
access
polysubstituted
3‐azabicyclo[3.1.1]heptanes
single
operation
from
readily
accessible
bicyclobutanes
(BCBs)
isocyanides.
The
process
is
proposed
involve
formal
(3+3)/(3+2)/retro‐(3+2)
cycloaddition
sequence.
This
novel
protocol
allows
for
rapid
generation
molecular
complexity
starting
materials,
products
be
easily
derivatized,
further
enriching
BCB
chemistry
growing
set
valuable
sp
3
‐rich
building
blocks.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(8), P. 5232 - 5241
Published: Feb. 13, 2024
In
pursuit
of
potent
pharmaceutical
candidates
and
to
further
improve
their
chemical
traits,
small
ring
systems
can
serve
as
a
potential
starting
point.
Small
units
have
the
additional
merit
loaded
strain
at
core,
making
them
suitable
reactants
they
capitalize
on
this
intrinsic
driving
force.
With
introduction
cyclobutenone
strained
precursor
ketene,
photocycloaddition
with
another
unit,
bicyclo[1.1.0]butane
(BCB),
enables
reactivity
both
π-units
in
transient
ketene.
This
double
strain-release
driven
[2π+2σ]-photocycloaddition
promotes
synthesis
diverse
heterobicyclo[2.1.1]hexane
units,
pharmaceutically
relevant
bioisostere.
The
effective
under
catalyst-free
conditions
high
functional
group
tolerance
defines
its
synthetic
utility.
Experimental
mechanistic
studies
density
theory
(DFT)
calculations
suggest
that
takes
place
via
triplet
mechanism.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(27), P. 18565 - 18575
Published: June 27, 2024
Bridged
bicyclic
scaffolds
are
emerging
bioisosteres
of
planar
aromatic
rings
under
the
concept
"escape
from
flatland".
However,
adopting
this
into
exploration
pyridines
remains
elusive
due
to
challenge
incorporating
a
N
atom
such
bridged
structures.
Herein,
we
report
practical
routes
for
divergent
synthesis
2-
and
3-azabicyclo[3.1.1]heptenes
(aza-BCHepes)
as
potential
readily
accessible
vinyl
azides
bicyclo[1.1.0]butanes
(BCBs)
via
two
distinct
catalytic
annulations.
The
reactivity
tailored
with
BCBs
is
key
achieving
transformations.
Ti
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(29)
Published: May 11, 2024
Abstract
The
exploration
of
the
complex
chemical
diversity
bicyclo[n.1.1]alkanes
and
their
use
as
benzene
bioisosteres
has
garnered
significant
attention
over
past
two
decades.
Regiodivergent
syntheses
thiabicyclo[4.1.1]octanes
(S‐BCOs)
highly
substituted
bicyclo[2.1.1]hexanes
(BCHs)
using
a
Lewis
acid‐catalyzed
formal
cycloaddition
bicyclobutanes
(BCBs)
3‐benzylideneindoline‐2‐thione
derivatives
have
been
established.
first
hetero‐(4+3)
BCBs,
catalyzed
by
Zn(OTf)
2
,
was
achieved
with
broad
substrate
scope
under
mild
conditions.
In
contrast,
less
electrophilic
BCB
ester
undergoes
Sc(OTf)
3
‐catalyzed
[2π+2σ]
reaction
1,1,2‐trisubstituted
alkenes,
yielding
BCHs
spirocyclic
quaternary
carbon
center.
Control
experiments
preliminary
theoretical
calculations
suggest
that
diastereoselective
product
formation
may
involve
concerted
between
zwitterionic
intermediate
E
‐1,1,2‐trisubstituted
alkenes.
Additionally,
nucleophilic
ring‐opening
mechanism.