Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(25)
Published: April 11, 2024
Abstract
While
polyborylated
alkenes
are
being
recognized
for
their
elevated
status
as
highly
valuable
reagents
in
modern
organic
synthesis,
allowing
efficient
access
to
a
diverse
array
of
transformations,
including
the
formation
C−C
and
C‐heteroatom
bonds,
potential
energy‐transfer
reactive
groups
has
remained
unexplored.
Yet,
this
holds
key
generating
elusive
biradical
species,
which
can
be
captured
by
olefins,
thereby
leading
construction
new
highly‐borylated
scaffolds.
Herein,
we
report
designed
strategy
photosensitized
[2+2]‐cycloadditions
poly‐borylated
with
various
olefins
enabling
regioselective
synthesis
cyclobutane
motifs,
1,1‐di‐,
1,1,2‐tri‐,
1,1,2,2‐tetra‐borylated
cyclobutanes.
In
fact,
these
compounds
belong
family
that
presently
lacks
synthetic
pathways.
Interestingly,
when
α‐methylstyrene
was
used,
reaction
involves
an
interesting
1,5‐hydrogen
atom
transfer
(HAT).
Mechanistic
deuterium‐labeling
studies
have
provided
insight
into
outcome
process.
addition,
cyclobutanes
then
demonstrated
useful
selective
oxidation
processes
resulting
cyclobutanones
γ‐lactones.
Chemical Society Reviews,
Journal Year:
2024,
Volume and Issue:
53(3), P. 1068 - 1089
Published: Jan. 1, 2024
Leveraging
light
energy
to
expose
the
‘dark’
reactive
states
describes
whole
essence
of
triplet–triplet
transfer.
This
offers
an
impressive
opportunity
conduct
a
multitude
diverse
reactions
and
access
sought-after
molecular
motifs.
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(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.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(43), P. 23771 - 23780
Published: Oct. 18, 2023
Given
the
importance
of
cyclic
frameworks
in
molecular
scaffolds
and
drug
discovery,
it
is
intriguing
to
precisely
forge
manipulate
ring
systems
synthetic
chemistry.
In
this
field,
intermolecular
synthesis
densely
substituted
cyclobutanes
with
precise
diastereocontrol
under
simple
reaction
conditions
remains
a
challenge.
Herein,
photoredox
strategy
for
difunctionalization
bicyclo[1.1.0]butanes
(BCBs)
high
regio-
syn-selectivity
disclosed.
C-S
σ-bond
cleavage
partially
unsaturated
sulfur-containing
bifunctional
reagents
an
overall
strain-release-driven
process
enables
thio-alkynylation,
-alkenylation,
-allylation
BCBs
mild
demonstrates
generality
protocol.
Mechanistic
studies
suggest
that
intermediacy
distonic
radical
cations
might
be
key
efficient
scission
σ-bonds
origin
diastereoselectivity.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(25)
Published: April 11, 2024
Abstract
While
polyborylated
alkenes
are
being
recognized
for
their
elevated
status
as
highly
valuable
reagents
in
modern
organic
synthesis,
allowing
efficient
access
to
a
diverse
array
of
transformations,
including
the
formation
C−C
and
C‐heteroatom
bonds,
potential
energy‐transfer
reactive
groups
has
remained
unexplored.
Yet,
this
holds
key
generating
elusive
biradical
species,
which
can
be
captured
by
olefins,
thereby
leading
construction
new
highly‐borylated
scaffolds.
Herein,
we
report
designed
strategy
photosensitized
[2+2]‐cycloadditions
poly‐borylated
with
various
olefins
enabling
regioselective
synthesis
cyclobutane
motifs,
1,1‐di‐,
1,1,2‐tri‐,
1,1,2,2‐tetra‐borylated
cyclobutanes.
In
fact,
these
compounds
belong
family
that
presently
lacks
synthetic
pathways.
Interestingly,
when
α‐methylstyrene
was
used,
reaction
involves
an
interesting
1,5‐hydrogen
atom
transfer
(HAT).
Mechanistic
deuterium‐labeling
studies
have
provided
insight
into
outcome
process.
addition,
cyclobutanes
then
demonstrated
useful
selective
oxidation
processes
resulting
cyclobutanones
γ‐lactones.
Journal of the American Chemical Society,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 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.
Journal of the American Chemical Society,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 10, 2025
(+)-Saxitoxin,
a
potent
neurotoxin
and
NaV
blocker,
poses
significant
synthetic
challenges
due
to
its
compact
tricyclic
framework
guanidinium
moieties.
We
report
concise
asymmetric
total
synthesis
featuring
an
intramolecular
[2
+
2]
photocycloaddition
of
alkenylboronate
ester
equipped
with
new
chiral
auxiliary.
This
auxiliary,
compatible
UV
light
easily
exchangeable
on
B(pin)
derivatives,
enabled
high
stereocontrol
through
hydrogen-bond-mediated
transition-state
stabilization.
Our
approach
not
only
introduces
innovative
surrogate
for
Michael
addition,
particularly
addressing
transformations
contra-thermodynamic
barriers,
but
also
highlights
the
potential
boron-enabled
photochemistry
synthesizing
complex
molecules.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(22), P. 14948 - 14953
Published: May 22, 2024
The
truxillates
constitute
a
large
class
of
dimeric
natural
products
featuring
central,
highly
substituted
cyclobutane
core.
In
principle,
these
structures
could
be
efficiently
synthesized
via
[2
+
2]
photocycloaddition.
However,
the
difficulty
in
controlling
high-energy
electronically
excited
reactive
intermediates
solution
state
can
lead
to
poor
regio-
and
diastereocontrol.
This
has
limited
use
photocycloaddition
methodology
toward
synthesis
this
important
products.
Herein,
we
demonstrate
that
acid-controlled
precipitation
C-acyl
imidazoles
promotes
selective
solid-state
photocycloaddition,
reaction
quickly
transformed
into
truxillate
