ACS Catalysis,
Год журнала:
2024,
Номер
14(21), С. 16479 - 16487
Опубликована: Окт. 23, 2024
In
contemporary
organic
synthesis,
chemists
actively
pursue
a
diverse
range
of
substrates
that
can
be
efficiently
catalyzed
within
an
integrated
system,
playing
crucial
role
in
advancing
the
pharmaceutical
industry.
However,
due
to
influence
substituents
on
reactivity
and
selectivity,
it
poses
challenging
dilemma
explore
different
strategies
for
activating
with
distinct
functional
groups.
Herein,
we
have
developed
important
visible
light-driven
chiral
Lewis
acid
catalysis
platform
which
facilitates
unified
allylations
vinylogous
reactions
various
allyl
bromides
isatins
highly
enantio-
diastereoselective
construction
valuable
3-allyl-3-hydroxy
oxindoles.
The
success
this
approach
lies
utilizing
radical
pathway
intermediate
formation
stereocenter
generation.
Moreover,
activation
capability
acids
provides
opportunity
achieve
sufficient
enantiocontrol
enhance
regioselectivity.
robustness
method
is
demonstrated
by
its
application
precise
radical-based
propargylation
using
readily
accessible
propargyl
bromides.
Abstract
Transition‐metal‐catalyzed
radical
relay
cross‐coupling
reactions
of
1,3‐dienes
have
recently
emerged
as
one
the
most
powerful
methods
for
construction
structurally
diverse
allylic
compound
in
a
single
chemical
step.
However,
there
still
has
been
limited
success
expanding
substrate
scope
precursors
and
coupling
partners,
well
exploring
catalytic
asymmetric
variants.
Herein,
we
report
copper‐catalyzed
enantioselective
three‐component
1,2‐alkylesterification
using
cycloalkyl
hydroperoxides
carbonyl‐containing
alkyl
sources
carboxylic
acids
O‐nucleophiles
under
mild
redox‐neutral
conditions.
This
protocol
features
broad
good
functional
group
tolerance
with
respect
to
each
component,
providing
practical
access
variety
distally
keto‐functionalized
esters
high
enantioselectivity.
Mechanistic
studies
suggest
involvement
sequential
C−O
this
reaction.
Organic Letters,
Год журнала:
2024,
Номер
26(2), С. 565 - 570
Опубликована: Янв. 4, 2024
An
aerobic
oxidative
cleavage
of
1,3-diketones
under
visible
light
irradiation
using
an
organic
dye
as
a
photocatalyst
is
disclosed.
The
newly
developed
reaction
provides
practical
access
to
1,2-diketones
and
(Z)-1,4-enediones
in
moderate
good
yields
with
absolute
regio-
stereoselectivity.
Mechanistic
studies
the
suggest
that
tetraketone
intermediates
might
undergo
photocatalytic
energy
transfer
from
excited
form
biradical-like
(n,π*)
states
ketones.
Angewandte Chemie,
Год журнала:
2023,
Номер
136(1)
Опубликована: Ноя. 21, 2023
Abstract
The
direct
α‐alkylation
of
acyclic
carbonyls
with
nonactivated
hydrocarbons
through
C(sp
3
)−H
functionalization
is
both
extremely
promising
and
notably
challenging,
especially
when
attempting
to
achieve
enantioselectivity
using
iron‐based
catalysts.
We
have
identified
a
robust
chiral
iron
complex
for
the
oxidative
cross‐coupling
2‐acylimidazoles
benzylic
allylic
hydrocarbons,
as
well
alkanes.
readily
available
tunable
N,N
′‐dioxide
catalysts
in
connection
oxidants
exhibit
precise
asymmetric
induction
(up
99
%
ee
)
good
compatibility
moderate
yields
88
yield).
This
protocol
provides
an
elegant
straightforward
access
optically
active
carbonyl
derivatives
starting
from
simple
alkanes
without
prefunctionalization.
Density
functional
theory
(DFT)
calculations
control
experiments
were
made
gain
insight
into
nature
C−C
bond
formation
origin
enantioselectivity.
propose
radical‐radical
process
enabled
by
immediate
interconversion
between
ferric
species
ferrous
species.
Benzoheteroles
are
promising
structural
scaffolds
in
the
realm
of
medicinal
chemistry,
but
sustainable
synthesis
2,3-difunctionalized
benzoheterole
derivatives
is
still
high
demand.
Indeed,
we
have
conceptually
rationalized
intrinsic
reactivity
propargylic-enyne
systems
for
flexible
construction
2,3-disubstituted
benzoheteroles
through
radical
sulfonylative-cyclization
cascade
under
organophotoredox
catalysis.
We
hereby
report
an
efficient
visible-light-induced
sulfonyl
radical-triggered
cyclization
1,6-enynols
with
sulfinic
acids
dual
catalytic
influence
4CzIPN
and
NiBr
Advanced Synthesis & Catalysis,
Год журнала:
2024,
Номер
366(19), С. 4132 - 4138
Опубликована: Июль 19, 2024
Abstract
In
this
work,
silyl
ethers
of
phenols
and
alcohols
have
been
successfully
prepared
tested
as
neutral
carbon
(silicon)
centered
radical
precursors.
The
organophotocatalyzed
oxidation
(by
the
Fukuzumi
catalyst)
these
caused
cleavage
a
C−Si
(or
Si−Si)
bond
for
release
desired
to
be
used
forging
C(
sp
3
)
−C(
−Si)
bonds
via
Giese
reaction.
Research Square (Research Square),
Год журнала:
2024,
Номер
unknown
Опубликована: Авг. 19, 2024
Abstract
The
activation
of
C−C
bond
benzocyclobutenones
under
mild
reaction
conditions
remains
a
challenge.
We
herein
report
photoinduced
catalyst-free
regio-specific
C1−C8
cleavage
benzocyclobutenones,
enabling
the
generation
versatile
ortho-quinoid
ketene
methides
for
aza-[4
+
2]-cycloaddition
with
imines,
which
offers
facile
route
to
isoquinolinone
derivatives,
including
seven
family
members
protoberberine
alkaloids,
gusanlung
A,
B,
D,
8-oxotetrahydroplamatine,
tetrahydrothalifendine,
tetrahydropalmatine,
and
xylopinine.
Furthermore,
catalytic
enantioselective
version
this
strategy
was
realized
by
merging
synergistic
photocatalysis
chiral
Lewis
acid
catalysis.
Mechanistic
studies
provided
compelling
evidence
rationalize
photoisomerization/cycloaddition
cascade
process.
ACS Catalysis,
Год журнала:
2024,
Номер
14(21), С. 16479 - 16487
Опубликована: Окт. 23, 2024
In
contemporary
organic
synthesis,
chemists
actively
pursue
a
diverse
range
of
substrates
that
can
be
efficiently
catalyzed
within
an
integrated
system,
playing
crucial
role
in
advancing
the
pharmaceutical
industry.
However,
due
to
influence
substituents
on
reactivity
and
selectivity,
it
poses
challenging
dilemma
explore
different
strategies
for
activating
with
distinct
functional
groups.
Herein,
we
have
developed
important
visible
light-driven
chiral
Lewis
acid
catalysis
platform
which
facilitates
unified
allylations
vinylogous
reactions
various
allyl
bromides
isatins
highly
enantio-
diastereoselective
construction
valuable
3-allyl-3-hydroxy
oxindoles.
The
success
this
approach
lies
utilizing
radical
pathway
intermediate
formation
stereocenter
generation.
Moreover,
activation
capability
acids
provides
opportunity
achieve
sufficient
enantiocontrol
enhance
regioselectivity.
robustness
method
is
demonstrated
by
its
application
precise
radical-based
propargylation
using
readily
accessible
propargyl
bromides.
