The Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
89(20), P. 15151 - 15157
Published: Sept. 27, 2024
Here,
we
present
a
mild
and
rapid
method
to
access
azidobicyclo[2.1.1]hexanes
via
formal
(3
+
2)
cycloaddition
of
α-substituted
vinyl
azides
bicyclo[1.1.0]butanes
under
Lewis
acid
catalysis.
A
wide
range
were
tolerated
conditions.
Notably,
the
resulting
cycloadducts
could
be
transformed
into
structurally
attractive
3-azabicyclo[3.1.1]heptenes
through
microwave-promoted
rearrangement.
The
utilities
highlighted
by
copper(I)-catalyzed
Huisgen
1,3-dipolar
tertiary
alkyl
azide
further
transformation
ketone
groups.
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.
Asian Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
13(5)
Published: Feb. 21, 2024
Abstract
Within
a
medicinal
chemist's
toolbox,
one
of
the
most
effective
strategies
to
improve
overall
properties
biologically
active
compound
is
bioisosteric
replacement.
Ever
since
first
example
replacing
benzene
with
bicyclo[1.1.1]pentane
(BCP)
group
was
published
in
late
1990s,
[1]
chemistry
community
has
continually
been
expanding
scope
such
phenyl
replacements.
Recent
interest
from
academia
focused
on
novel
synthetic
access
C(
sp
3
)‐rich
bicyclic
hydrocarbons
expanded
ring
sizes.
Herein,
we
summarize
some
these
transformations
and
reveal
that
rely
strain
releasing
cycloadditions
bicyclo[1.1.0]butane
(BCB)
bicyclo[2.1.0]pentane
(housane).
We
have
organized
this
review
based
mechanism
release
strategies,
namely,
carbene
cycloadditions,
energy
transfer
photocatalyzed
electron
catalyzed
polar
cycloadditions.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(14), P. 10142 - 10149
Published: March 27, 2024
Saturated
bicyclic
compounds
make
up
a
valuable
class
of
building
blocks
in
the
development
agrochemicals
and
pharmaceuticals.
Here,
we
present
synthesis
borylated
bicyclo[2.1.1]hexanes
via
crossed
[2
+
2]-cycloaddition.
Due
to
presence
C–B
bond,
variety
structures
can
be
easily
prepared
that
are
not
accessible
by
other
methods.
Moreover,
rare
photo-ene
reaction
is
also
disclosed,
allowing
for
diastereoselective
trisubstituted
cyclopentanes.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(32)
Published: May 24, 2024
Abstract
Synthesis
of
bicyclic
scaffolds
has
gained
significant
attention
in
drug
discovery
due
to
their
potential
mimic
benzene
bioisosteres.
Here,
we
present
a
mild
and
scalable
Sc(OTf)
3
‐catalyzed
[3+2]
cycloaddition
bicyclo[1.1.0]butanes
(BCBs)
with
ynamides,
yielding
diverse
array
polysubstituted
2‐amino‐bicyclo[2.1.1]hexenes
good
excellent
yields.
These
products
offer
valuable
starting
materials
for
the
construction
novel
functionalized
bicyclo[1.1.0]butanes.
Preliminary
mechanistic
studies
indicate
that
reaction
involves
nucleophilic
addition
ynamides
bicyclo[1.1.0]butanes,
followed
by
an
intramolecular
cyclization
situ
generated
enolate
keteniminium
ion.
We
expect
these
findings
will
encourage
utilization
complex
bioisosteres
foster
further
investigation
into
BCB‐based
chemistry.
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: May 23, 2024
Abstract
Natural
stilbenes
have
shown
significant
potential
in
the
prevention
and
treatment
of
diseases
due
to
their
diverse
pharmacological
activities.
Here
we
present
a
mild
effective
Ti-catalyzed
intermolecular
radical-relay
[2σ
+
2π]
cycloaddition
bicyclo[1.1.0]-butanes
1,3-dienes.
This
transformation
enables
synthesis
bicyclo[2.1.1]hexane
(BCH)
scaffolds
containing
aryl
vinyl
groups
with
excellent
regio-
trans
-selectivity
broad
functional
group
tolerance,
thus
offering
rapid
access
structurally
stilbene
bioisosteres.
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: July 20, 2024
Abstract
Saturated
three-dimensional
carbocycles
have
gained
increasing
prominence
in
synthetic
and
medicinal
chemistry.
In
particular,
bicyclo[2.1.1]hexanes
(BCHs)
been
identified
as
the
molecular
replacement
for
benzenes.
Here,
we
present
facile
access
to
a
variety
of
BCHs
via
stepwise
two-electron
formal
(3
+
2)
cycloaddition
between
silyl
enol
ethers
bicyclo[1.1.0]butanes
(BCBs)
under
Lewis
acid
catalysis.
The
reaction
features
wide
functional
group
tolerance
ethers,
allowing
efficient
construction
two
vicinal
quaternary
carbon
centers
silyl-protected
tertiary
alcohol
unit
streamlined
fashion.
Interestingly,
with
conjugated
dienol
can
provide
bicyclo[4.1.1]octanes
(BCOs)
equipped
that
facilitate
further
transformation.
utilities
this
methodology
are
demonstrated
by
late-stage
modification
natural
products,
transformations
units
on
bicyclo[2.1.1]hexane
frameworks,
derivatization
bicyclo[4.1.1]octanes,
delivering
functionalized
bicycles
traditionally
inaccessible.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
unknown
Published: Nov. 2, 2023
1-Substituted
bicyclo[1.1.0]butanes
add
enantioselectively
to
2(1H)-quinolones
upon
irradiation
(λ
=
366
nm)
in
the
presence
of
a
chiral
complexing
agent.
A
two-point
hydrogen
bond
between
quinolone
and
template
is
responsible
for
stereocontrol
photocycloaddition
reaction.
The
reaction
leads
formation
products
with
bicyclo[2.1.1]hexane
skeleton
high
enantiomeric
excess
(91-99%
ee).
can
be
almost
quantitatively
(97%)
recovered
used
another
triplet
pathway
likely,
sensitization
suitable
tool
if
performed
visible
light
420
nm).
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Sept. 30, 2024
Achieving
structural
and
stereogenic
diversity
from
the
same
starting
materials
remains
a
fundamental
challenge
in
organic
synthesis,
requiring
precise
control
over
selectivity.
Here,
we
report
divergent
catalytic
methods
that
selectively
yield
either
cycloaddition
or
addition/elimination
products
bicyclo[1.1.0]butanes
α,β-unsaturated
ketones.
By
employing
chiral
Lewis
acid
Brønsted
catalysts,
achieved
excellent
regio-,
diastereo-,
enantioselectivity
across
all
three
distinct
transformations,
affording
diverse
array
of
synthetically
valuable
bicyclo[2.1.1]hexanes
cyclobutenes.
The
outcomes
are
controlled
by
differential
activation
substrates
specific
catalyst
with
reaction
conditions
dictating
pathway
This
strategy
demonstrates
power
catalysis
creating
molecular
complexity
diversity,
offering
tool
for
synthesis
enantioenriched
building
blocks.