Angewandte Chemie International Edition,
Год журнала:
2021,
Номер
60(33), С. 17925 - 17931
Опубликована: Июнь 7, 2021
Single-electron
N-heterocyclic
carbene
(NHC)
catalysis
has
gained
attention
recently
for
the
synthesis
of
C-C
bonds.
Guided
by
density
functional
theory
and
mechanistic
analyses,
we
report
light-driven
aliphatic
α-amino
ketones
using
single-electron
NHC
operators.
Computational
experimental
results
reveal
that
reactivity
key
radical
intermediate
is
substrate-dependent
can
be
modulated
through
steric
electronic
parameters
NHC.
Catalyst
potential
harnessed
in
visible-light
driven
generation
an
acyl
azolium
species
undergoes
selective
coupling
with
various
partners
to
afford
diverse
ketone
products.
This
methodology
showcased
direct
late-stage
functionalization
amino
acids
pharmaceutical
compounds,
highlighting
utility
Chemical Reviews,
Год журнала:
2020,
Номер
121(1), С. 506 - 561
Опубликована: Май 29, 2020
Thermal
C–C
bond
cleavage
reactions
allow
the
construction
of
structurally
diverse
molecular
skeletons
via
predictable
and
efficient
reorganizations.
Visible
light
photoredox-catalyzed
radical-mediated
have
recently
emerged
as
a
powerful
alternative
method
for
overcoming
thermodynamic
kinetic
barrier
in
scaffolds.
In
recent
years,
plethora
elegant
useful
been
invented,
products
are
sometimes
otherwise
inaccessible
by
classic
thermal
reactions.
Considering
great
influence
synthetic
potential
these
reactions,
we
provide
summary
state
art
visible
light-driven
cleavage/functionalization
strategies
with
specific
emphasis
on
working
models.
We
hoped
that
this
review
will
be
medicinal
organic
chemists
inspire
further
reaction
development
interesting
area.
Chemical Reviews,
Год журнала:
2021,
Номер
122(2), С. 2292 - 2352
Опубликована: Дек. 9, 2021
The
halogen-atom
transfer
(XAT)
is
one
of
the
most
important
and
applied
processes
for
generation
carbon
radicals
in
synthetic
chemistry.
In
this
review,
we
summarize
highlight
aspects
associated
with
XAT
impact
it
has
had
on
photochemistry
photocatalysis.
organization
material
starts
analysis
mechanistic
then
follows
a
subdivision
based
nature
reagents
used
halogen
abstraction.
This
review
aims
to
provide
general
overview
fundamental
concepts
main
agents
involved
objective
offering
tool
understand
facilitate
development
new
radical
strategies.
Chemical Reviews,
Год журнала:
2021,
Номер
122(2), С. 2017 - 2291
Опубликована: Ноя. 23, 2021
We
present
here
a
review
of
the
photochemical
and
electrochemical
applications
multi-site
proton-coupled
electron
transfer
(MS-PCET)
in
organic
synthesis.
MS-PCETs
are
redox
mechanisms
which
both
an
proton
exchanged
together,
often
concerted
elementary
step.
As
such,
MS-PCET
can
function
as
non-classical
mechanism
for
homolytic
bond
activation,
providing
opportunities
to
generate
synthetically
useful
free
radical
intermediates
directly
from
wide
variety
common
functional
groups.
introduction
practitioner’s
guide
reaction
design,
with
emphasis
on
unique
energetic
selectivity
features
that
characteristic
this
class.
then
chapters
oxidative
N–H,
O–H,
S–H,
C–H
homolysis
methods,
generation
corresponding
neutral
species.
Then,
reductive
PCET
activations
involving
carbonyl,
imine,
other
X═Y
π-systems,
heteroarenes,
where
ketyl,
α-amino,
heteroarene-derived
radicals
be
generated.
Finally,
we
asymmetric
catalysis
materials
device
applications.
Within
each
chapter,
subdivide
by
group
undergoing
homolysis,
thereafter
type
transformation
being
promoted.
Methods
published
prior
end
December
2020
presented.
Chemical Reviews,
Год журнала:
2021,
Номер
122(2), С. 2487 - 2649
Опубликована: Ноя. 9, 2021
Redox
processes
are
at
the
heart
of
synthetic
methods
that
rely
on
either
electrochemistry
or
photoredox
catalysis,
but
how
do
and
catalysis
compare?
Both
approaches
provide
access
to
high
energy
intermediates
(e.g.,
radicals)
enable
bond
formations
not
constrained
by
rules
ionic
2
electron
(e)
mechanisms.
Instead,
they
1e
mechanisms
capable
bypassing
electronic
steric
limitations
protecting
group
requirements,
thus
enabling
chemists
disconnect
molecules
in
new
different
ways.
However,
while
providing
similar
intermediates,
differ
several
physical
chemistry
principles.
Understanding
those
differences
can
be
key
designing
transformations
forging
disconnections.
This
review
aims
highlight
these
similarities
between
comparing
their
underlying
principles
describing
impact
electrochemical
photochemical
methods.
Chemical Reviews,
Год журнала:
2023,
Номер
123(8), С. 4237 - 4352
Опубликована: Янв. 24, 2023
The
emergence
of
modern
photocatalysis,
characterized
by
mildness
and
selectivity,
has
significantly
spurred
innovative
late-stage
C–H
functionalization
approaches
that
make
use
low
energy
photons
as
a
controllable
source.
Compared
to
traditional
strategies,
photocatalysis
paves
the
way
toward
complementary
and/or
previously
unattainable
regio-
chemoselectivities.
Merging
compelling
benefits
with
workflow
offers
potentially
unmatched
arsenal
tackle
drug
development
campaigns
beyond.
This
Review
highlights
photocatalytic
strategies
small-molecule
drugs,
agrochemicals,
natural
products,
classified
according
targeted
bond
newly
formed
one.
Emphasis
is
devoted
identifying,
describing,
comparing
main
mechanistic
scenarios.
draws
critical
comparison
between
established
ionic
chemistry
photocatalyzed
radical-based
manifolds.
aims
establish
current
state-of-the-art
illustrate
key
unsolved
challenges
be
addressed
in
future.
authors
aim
introduce
general
readership
functionalization,
specialist
practitioners
evaluation
methodologies,
potential
for
improvement,
future
uncharted
directions.
Chemical Reviews,
Год журнала:
2022,
Номер
122(6), С. 5842 - 5976
Опубликована: Янв. 24, 2022
Benefiting
from
the
impressive
increase
in
fundamental
knowledge,
last
20
years
have
shown
a
continuous
burst
of
new
ideas
and
consequently
plethora
catalytic
methods
for
enantioselective
radical
reactions.
This
review
aims
to
provide
complete
survey
progress
achieved
over
this
latter
period.
The
first
part
focuses
on
use
chiral
organocatalysts,
these
include
catalysts
covalently
linked
substrate
those
that
interact
with
by
weaker
interactions
like
hydrogen
bonds.
second
is
devoted
transition-metal
redox
catalysis
which
organized
according
increasing
atomic
number
first-row
transition
metals
(Ti,
Cr,
Fe,
Mn,
Co,
Ni,
Cu).
Bioinspired
manganese-
iron-mediated
hydroxylations
oxidations
are
also
discussed.
A
specific
section
dedicated
reactivity
Ru,
Rh,
Ir
complexes
as
Lewis
acids
special
focus
at
metal.
Absorption
photons
result
different
events
such
energy
transfer,
single-electron
hydrogen-atom
transfer
facilitating
formation
radicals.
Organocatalysis
has
been
successfully
combined
photocatalysts,
opened
pathways
enlarging
precursors
available.
merger
photocatalysis
organo-
or
metalla-photocatalysis
brought
novelty
allowed
discovery
large
original
transformations.
enzyme-catalyzed
reactions
involving
intermediates
largely
benefit
visible-light
irradiation
included
review.
provides
comprehensive
inventory
goal
detailing
reaction
mechanisms
involved
transformations
any
nonspecialist
could
find
their
own
creativity
invent
yet
unknown
applications.
ACS Catalysis,
Год журнала:
2022,
Номер
12(19), С. 11984 - 11999
Опубликована: Сен. 19, 2022
Radical/radical
cross-coupling
reactions
represent
an
efficient
and
straightforward
approach
for
the
construction
of
chemical
bonds
accordingly
have
drawn
increasing
attention
over
past
decades.
In
order
to
achieve
synthetically
useful
transformations,
a
persistent
radical
should
be
coupled
with
transient
in
accordance
effect
(PRE).
However,
known
radicals
outnumber
by
far
types
free
radicals,
which
limits
widespread
application
PRE,
until
today.
Thus,
development
between
has
been
focus,
meanwhile
transition-metal
catalysis
successfully
implemented
artificially
prolong
lifetimes,
allowing
their
utilization
formal
radical/radical
cross-couplings.
Complementary
research
field
recently
uncovered
that
organocatalytically
generated
NHC-derived
ketyl
are
type
catalytically
radicals.
NHC-catalyzed
transformations
aldehydes
carboxylic
acid
derivatives
enabled
disclosure
ever-increasing
number
interesting
reactions,
different
from
traditional
ionic
processes,
offering
otherwise
inaccessible
activation
modes.
These
discoveries
opened
door
NHC
organocatalysis
manipulation
reactions.
Due
its
obvious
potential
synthetic
organic
chemistry,
it
is
timely
provide
perspective
on
this
emerging
field.
Angewandte Chemie International Edition,
Год журнала:
2020,
Номер
59(23), С. 9143 - 9148
Опубликована: Март 2, 2020
Abstract
As
a
key
element
in
the
construction
of
complex
organic
scaffolds,
formation
C−C
bonds
remains
challenge
field
synthetic
chemistry.
Recent
advancements
single‐electron
chemistry
have
enabled
new
methods
for
various
bonds.
Disclosed
herein
is
development
novel
reduction
acyl
azoliums
ketones
from
carboxylic
acids.
Facile
azolium
situ
followed
by
radical–radical
coupling
was
made
possible
merging
N‐heterocyclic
carbene
(NHC)
and
photoredox
catalysis.
The
utility
this
protocol
synthesis
showcased
late‐stage
functionalization
variety
pharmaceutical
compounds.
Preliminary
investigations
using
chiral
NHCs
demonstrate
that
enantioselectivity
can
be
achieved,
showcasing
advantages
over
alternative
methodologies.
ACS Catalysis,
Год журнала:
2019,
Номер
10(2), С. 1621 - 1627
Опубликована: Дек. 18, 2019
The
direct
conversion
of
feedstock
chemicals
into
value-added
products
is
broad
interest
in
chemical
research.
Herein,
we
present
a
regioselective
and
diastereoselective
three-component
dialkylation
1,3-dienes
with
Hantzsch
esters
aldehydes
for
the
synthesis
homoallylic
alcohols.
reaction
enabled
by
dual
photoredox
chromium
catalysis
can
also
be
performed
enantioselectively
employing
chromium-bisoxazoline
complexes.
Chemical Society Reviews,
Год журнала:
2021,
Номер
50(22), С. 12808 - 12827
Опубликована: Янв. 1, 2021
Transition
metal-catalysed
asymmetric
coupling
has
been
established
as
a
robust
tool
for
constructing
complex
organic
molecules.
Although
this
area
extensively
studied,
the
development
of
efficient
protocols
to
construct
stereogenic
centres
with
excellent
regio-
and
enantioselectivities
is
highly
desirable
remains
challenging.
Asymmetric
transition
metal
catalysis
light
intervention
provides
practical
alternative
strategy
current
methods
considerably
expands
synthetic
utility
result
abundant
feedstocks
mild
conditions.
This
tutorial
review
comprehensively
summarizes
recent
advances
in
transition-metal-catalysed
reactions
intervention;
particular,
concise
analysis
substrate
scope
mechanistic
scenarios
governing
stereocontrol
discussed.