Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
62(4)
Опубликована: Окт. 14, 2022
Abstract
The
field
of
strain‐driven,
radical
formal
cycloadditions
is
experiencing
a
surge
in
activity
motivated
by
renaissance
free
chemistry
and
growing
demand
for
sp
3
‐rich
ring
systems.
former
has
been
driven
large
part
the
rise
photoredox
catalysis,
latter
adoption
“Escape
from
Flatland”
concept
medicinal
chemistry.
In
years
since
these
broader
trends
emerged,
dozens
cycloadditions,
including
catalytic,
asymmetric
variants,
have
developed
that
operate
via
mechanisms.
While
cyclopropanes
studied
most
extensively,
variety
strained
systems
are
amenable
to
design
analogous
reactions.
Many
processes
generate
lucrative,
functionally
decorated
difficult
access
other
means.
Herein,
we
summarize
recent
efforts
this
area
analyze
state
field.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(48)
Опубликована: Сен. 2, 2024
Abstract
The
cycloaddition
reaction
involving
bicyclo[1.1.0]butanes
(BCBs)
offers
a
versatile
and
efficient
synthetic
platform
for
producing
C(sp
3
)‐rich
rigid
bridged
ring
scaffolds,
which
act
as
phenyl
bioisosteres.
However,
there
is
scarcity
of
catalytic
asymmetric
cycloadditions
BCBs
to
fulfill
the
need
enantioenriched
saturated
bicycles
in
drug
design
development.
In
this
study,
an
synthesis
valuable
azabicyclo[2.1.1]hexanes
(aza‐BCHs)
by
enantioselective
zinc‐catalyzed
(3+2)
with
imines
reported.
proceeds
effectively
novel
type
BCB
that
incorporates
2‐acyl
imidazole
group
diverse
array
alkynyl‐
aryl‐substituted
imines.
target
aza‐BCHs,
consist
α‐chiral
amine
fragments
two
quaternary
carbon
centers,
are
efficiently
synthesized
up
94
%
96.5:3.5
er
under
mild
conditions.
Experimental
computational
studies
reveal
follows
concerted
nucleophilic
ring‐opening
mechanism
This
distinct
from
previous
on
Lewis
acid‐catalyzed
BCBs.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 25, 2024
The
selective
construction
of
bridged
bicyclic
scaffolds
has
garnered
increasing
attention
because
their
extensive
use
as
saturated
bioisosteres
arene
in
pharmaceutical
industry.
However,
sharp
contrast
to
racemic
counterparts,
assembling
chiral
structures
an
enantioselective
and
regioselective
manner
remains
challenging.
Herein,
we
describe
our
protocol
for
constructing
2-oxa-3-azabicyclo[3.1.1]heptanes
(BCHeps)
by
[4π
+
2σ]
cycloadditions
bicyclo[1.1.0]butanes
(BCBs)
nitrones
taking
advantage
a
copper(II)
complex
Lewis
acid
catalyst.
This
method
features
mild
conditions,
good
functional
group
tolerance,
high
yield
(up
99%),
excellent
enantioselectivity
99%
ee).
Density
theory
(DFT)
calculation
elucidates
the
origin
reaction's
mechanism
BCB
activation
Cu(II)
complex.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Май 31, 2024
Bridged
cyclobutanes
and
sulfur
heterocycles
are
currently
under
intense
investigation
as
building
blocks
for
pharmaceutical
drug
design.
Two
formal
cycloaddition
modes
involving
bicyclobutanes
(BCBs)
pyridinium
1,4-zwitterionic
thiolate
derivatives
were
described
to
rapidly
expand
the
chemical
space
of
sulfur-containing
bridged
cyclobutanes.
By
using
Ni(ClO
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 17, 2025
Rigid
bicyclic
hydrocarbons
have
emerged
as
important
building
blocks
in
the
drug
discovery
industry.
Despite
progress
this
general
area,
bicyclo[2.1.0]pentanes
(housanes)
are
an
understudied
class
of
molecules.
Herein
we
report
unconventional
synthesis
borylated
housanes.
Our
method
features
a
broad
scope
and
high
diastereoselectivities
versatile
intermediates.
The
route
involves
strain-release
diboration
bicyclo[1.1.0]butane
intramolecular
deborylative
alkylation.
versatility
bridgehead
boronic
ester
was
demonstrated
several
functionalizations.
Lastly,
mechanism
reaction
investigated,
unusual
stereospecific
diastereoselective
ring
expansion
uncovered.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
62(4)
Опубликована: Окт. 14, 2022
Abstract
The
field
of
strain‐driven,
radical
formal
cycloadditions
is
experiencing
a
surge
in
activity
motivated
by
renaissance
free
chemistry
and
growing
demand
for
sp
3
‐rich
ring
systems.
former
has
been
driven
large
part
the
rise
photoredox
catalysis,
latter
adoption
“Escape
from
Flatland”
concept
medicinal
chemistry.
In
years
since
these
broader
trends
emerged,
dozens
cycloadditions,
including
catalytic,
asymmetric
variants,
have
developed
that
operate
via
mechanisms.
While
cyclopropanes
studied
most
extensively,
variety
strained
systems
are
amenable
to
design
analogous
reactions.
Many
processes
generate
lucrative,
functionally
decorated
difficult
access
other
means.
Herein,
we
summarize
recent
efforts
this
area
analyze
state
field.
