Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(25), P. 16990 - 16995
Published: June 13, 2024
A
novel
diazabenzacenaphthenium
photocatalyst,
N-BAP,
with
high
photoredox
abilities
and
visible-light
absorption
was
designed
prepared
in
one
step.
Under
irradiation,
N-BAP
promoted
the
four-electron
reduction
of
esters
presence
ammonium
oxalate
as
a
"traceless
reductant"
to
generate
carbinol
anion
intermediates
that
underwent
protonation
water
give
corresponding
alcohols.
The
resulting
anions
also
exhibited
nucleophilic
reactivity
under
photocatalytic
conditions
undergo
1,2-addition
second
carbonyl
compound,
affording
unsymmetric
1,2-diols.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(6)
Published: Jan. 8, 2024
Abstract
A
method
for
the
generation
of
tertiary
carbanions
via
a
deaminative
radical‐polar
crossover
is
reported
using
redox
active
imines
from
α‐tertiary
primary
amines.
variety
benzylic
amines
and
amino
esters
can
be
used
in
this
approach,
with
latter
engaging
novel
“aza‐Reformatsky”
reaction.
Electronic
trends
correlate
stability
resulting
carbanion
reaction
efficiency.
The
anions
trapped
different
electrophiles
including
aldehydes,
ketones,
imines,
Michael
acceptors,
H
2
O/D
O.
Selective
anion
formation
achieved
presence
another
equivalent
or
more
acidic
C−H
bond
both
an
inter‐
intramolecular
fashion.
Mechanistic
studies
suggest
intermediacy
discrete
intermediate.
Journal of the American Chemical Society,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 8, 2025
Nozaki–Hiyama–Kishi
(NHK)
reactions
offer
a
mild
approach
for
the
formation
of
alcohol
motifs
through
radical-polar
crossover-based
pathways
from
various
radical
precursors.
However,
application
multicomponent
NHK-type
reactions,
which
allow
multiple
bonds
in
single
step,
has
been
largely
restricted
to
bulky
alkyl
precursors,
thus
limiting
their
expanded
utilization.
Herein,
we
disclose
general
three-component
reaction
enabled
by
delayed
crossover,
efficiently
tolerates
plethora
precursors
that
were
previously
unavailable.
This
method
enables
modular
assembly
versatile
homoallylic
alcohols
feedstock
chemicals
with
excellent
chemo-,
regio-,
diastereo-,
and
enantioselectivities
step.
Experimental
studies
density
functional
theory
(DFT)
calculations
reveal
kinetically
favored
an
allylchromium(III)
species
is
paramount
enforcing
crossover
over
direct
addition.
Finally,
straightforward
transformations
applications
products
demonstrated,
showcasing
synthetic
utility
this
method.
ACS Catalysis,
Journal Year:
2022,
Volume and Issue:
12(5), P. 3249 - 3255
Published: Feb. 24, 2022
A
dual
organophotoredox/nickel-catalyzed
reductive
coupling
of
allenes
with
aldehydes
has
been
developed
for
the
rapid
assembly
anti-homoallylic
alcohols
high
levels
regioselectivities
(>20:1),
diastereoselectivities
(up
to
>20:1),
and
yields
91%).
The
allylation
was
realized
through
a
crucial
π-allylnickel
intermediate,
which
obtained
via
insertion
Ni–H
intermediate.
Moreover,
γ,γ-disubstituted
homoallylic
quaternary
stereocenter
can
also
be
prepared
by
this
protocol.
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
144(42), P. 19207 - 19218
Published: Oct. 14, 2022
With
the
rapid
development
of
photoredox
catalysis,
numerous
concepts
for
asymmetric
induction
were
successfully
and
broadly
adapted
from
polar
two-electron
transformations
to
radical
chemistry.
While
this
applies
organocatalysis
or
transition
metal
chemistry,
ion-pairing
catalysis
remains
a
niche
application
within
light-driven
reactions
today.
This
perspective
gives
an
overview
recent
examples,
strategies,
their
in
stereoselective
at
interface
photo(redox)
catalysis.
ACS Catalysis,
Journal Year:
2022,
Volume and Issue:
12(7), P. 3974 - 3984
Published: March 15, 2022
The
selective
activation
of
sp3
carbon–hydrogen
bonds
in
the
presence
multiple
C–H
is
challenging
and
remains
supreme
importance
chemical
research.
Late-stage
modification
complex
molecules
via
high
prevalence
organic
synthesis.
Herein,
we
describe
a
C(sp3)–H
bond
α-position
to
an
amine
carbanion
intermediate.
In
several
α-amine
sites,
only
one
specific
position
selectively
activated.
Applying
this
protocol,
proposed
intermediate
was
effectively
trapped
with
different
electrophiles
such
as
deuterium
(D+),
tritium
(T+),
or
carbonyl
compounds
compiling
over
50
examples.
Further,
methodology
used
install
drug-derivatives
(>10
drugs)
at
selected
late-stage
functionalization.
addition,
protocol
suitable
for
gram-scale
synthesis,
detailed
mechanistic
investigation
has
been
carried
out
support
our
hypothesis.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(18)
Published: Feb. 26, 2024
Photocatalytic
reactions
involving
a
reductive
radical-polar
crossover
(RRPCO)
generate
intermediates
with
carbanionic
reactivity.
Many
of
these
proposed
resemble
highly
reactive
organometallic
compounds.
However,
conditions
their
formation
are
generally
not
tolerated
by
isolated
versions
and
often
different
reactivity
is
observed.
Our
investigations
on
nature
under
commonly
used
photocatalytic
demonstrate
that
indeed
best
described
as
free,
superbasic
carbanions
capable
deprotonating
common
polar
solvents
usually
assumed
to
be
inert
such
acetonitrile,
dimethylformamide,
dimethylsulfoxide.
Their
basicity
only
towards
but
also
electrophiles,
aldehydes,
ketones,
esters,
comparable
the
in
gas-phase.
Previously
unsuccessful
transformations
thought
result
from
lack
explained
high
solvent
weakly
acidic
protons
reaction
partners.
An
intuitive
explanation
for
mode
action
photocatalytically
generated
provided,
which
enables
methods
verify
mechanisms
involve
an
RRPCO
step
identify
reasons
limitations
current
methods.
eScience,
Journal Year:
2024,
Volume and Issue:
4(5), P. 100255 - 100255
Published: March 15, 2024
Herein,
an
electrochemically
driven
catalyst-free
nucleophilic
aromatic
substitution
(SNAr)
of
electron-rich
fluoroarenes
with
carboxylic
acids
as
weak
nucleophiles
under
mild
conditions
was
reported.
A
series
highly
valuable
ester
derivatives
were
obtained
in
a
direct
and
rapid
way.
This
transformation
features
commercially
available
reagents
exceptionally
broad
substrate
scope
good
functional
group
tolerance,
using
cheap
abundant
electrodes
completed
within
short
reaction
time.
Gram-scale
synthesis
complex
biorelevant
compounds
ligation
further
highlighted
the
potential
utility
methodology.
The
mechanistic
investigations
density
theory
(DFT)
calculations
verified
feasibility
proposed
pathway
this
transformation.
Chemical Science,
Journal Year:
2022,
Volume and Issue:
13(26), P. 7855 - 7862
Published: Jan. 1, 2022
Ketyl-olefin
coupling
reactions
stand
as
one
of
the
fundamental
chemical
transformations
in
synthetic
chemistry
and
have
been
widely
employed
generation
complex
molecular
architectures
natural
product
synthesis.
However,
catalytic
ketyl-olefin
coupling,
until
recent
development
photoredox
electrosynthesis
through
single-electron
transfer
mechanisms,
has
remained
largely
undeveloped.
Herein,
we
describe
a
new
approach
to
achieve
by
halogen-atom
mechanism,
which
provides
innovative
efficient
access
various
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(10), P. 1689 - 1694
Published: March 3, 2023
A
halogen-atom
transfer
(XAT)
strategy
utilizing
α-aminoalkyl
radicals
allows
the
generation
of
aryl
at
room
temperature,
which
is
applied
for
intramolecular
cyclization
reactions
en
route
to
biologically
relevant
alkaloids.
Starting
from
simple
halogen-substituted
benzamides
under
visible
light
irradiation
in
presence
an
organophotocatalyst
(4CzIPN)
and
nBu3N
modular
construction
phenanthridinone
core,
gives
facile
access
drug
analogs
alkaloids,
e.g.,
Amaryllidaceae
family.
The
reaction
pathway
most
likely
involves
a
quantum
mechanical
tunneling
enabled
event
achieve
aromatization-halogen-atom
transfer.
