Acta Chimica Sinica,
Journal Year:
2023,
Volume and Issue:
81(2), P. 111 - 111
Published: Jan. 1, 2023
Unnatural
α-amino
acid
derivatives
are
greatly
important
in
pharmaceuticals
and
biochemicals
owing
to
their
diverse
biological
activities,
usually
serve
as
versatile
building
blocks
organic
synthesis
well.A
variety
of
approaches
have
been
developed
prepare
derivatives,
among
which
N-H
insertion
reactions
diazo
compounds
considered
be
one
the
most
direct
methods.These
typically
proceed
through
carbene
active
intermediates
that
derived
from
by
UV-induction
or
metal
catalysis.As
a
green
powerful
avenue
synthesis,
visible-light-mediated
methodology
has
also
applied
principally
intermediates.Due
single
reaction
mechanism
these
reactions,
however,
scope
were
limited
α-aryl
diazoacetates
can
directly
absorb
visible-light.Therefore,
exploring
new
activation
modes
is
conducive
expanding
applicable
type
visiblelight-mediated
reactions.Herein
we
report
visible-light-promoted
N-alkylation
(aza)aromatic
amines
with
ethyl
diazoacetate
based
on
proton-coupled
electron
transfer
(PCET).A
series
synthesized
combination
photocatalyst
Lewis-acid
catalyst.This
method
featured
mild
conditions,
good
functional
group
tolerance
wide
range
substrate
scope.Mechanism
experiments
indicated
involved
radical
intermediate
rather
than
engaged
conventional
reactions.According
fluorescence
quenching
experiment,
alkyl
was
formed
PCET
step
between
excited
photocatalyst.And
then
radicals
cross-coupling
occurred
under
coordination
produce
final
products.This
catalytic
strategy
expands
applications
visible-light
chemical
reactions.The
general
procedure
for
following:
Aniline
1a
(0.1
mmol),
2
(0.2
Fe(OTf)2
(0.02
mmol)
[Ir(ppy)2(NCMe)2]PF6
(0.005
dissolved
MeOH
(2
mL).Then
mixture
degassed
via
"freeze-pump-thaw"
(3
times).After
that,
resulting
stirred
irradiation
30
W
blue
LEDs
at
room
temperature.Upon
completion,
crude
product
purified
flash
chromatograph
silica
gel
give
product.
Abstract
An
operationally
simple
anhydrous
carbene
insertion
reaction
to
construct
DNA‐encoded
libraries
(DEL)
is
reported.
The
developed
employs
visible
light
photolysis
of
diazo
compounds
and
Reversible
Adsorption
Solid
Support
(RASS)
strategy.
From
readily
available
amines,
alcohols,
phenols,
carboxylic
acids,
a
variety
high‐value
molecules,
including
useful
unnatural
amino
ethers,
esters,
promising
clinical
drug
derivatives,
bioactive
molecules
have
been
constructed.
Chinese Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
43(8), P. 2591 - 2591
Published: Jan. 1, 2023
In
recent
years,
the
photochemical
organic
transformation
promoted
by
visible
light
has
aroused
interest
of
chemists.Compared
with
traditional
methods,
photoredox
catalysis
using
as
renewable
energy
been
proved
to
be
a
mild
and
powerful
tool,
which
can
promote
activation
molecules
single
electron
transfer
(SET)
process.There
are
lot
amino
functional
groups
in
structures
many
natural
products,
also
important
structural
units
some
drug
materials.Therefore,
activating
C-N
bond
these
substances
carrying
out
coupling
reactions
C-C
formation,
structure
compounds
effectively
modified,
so
obtain
various
functionalization.Therefore,
this
study
become
an
research
field
synthesis.The
results
breaking
its
application
formation
reaction
years
reviewed,
representative
examples
mechanisms
discussed.
Organic & Biomolecular Chemistry,
Journal Year:
2023,
Volume and Issue:
21(41), P. 8273 - 8278
Published: Jan. 1, 2023
Herein,
we
report
a
novel
regioselective
[2
+
1]
cyclization
reaction
of
2-pyridones
with
carbenes
generated
in
situ
via
visible
light
irradiation,
without
the
requirement
for
catalysts
or
additives.
The
diverse
functional
groups
and
diazo
compounds
exhibit
good
tolerance,
enabling
rapid
synthesis
highly
valuable
cyclopropanated
dihydro-2-pyridone
scaffolds
exceptional
regio-
stereoselectivity.
Furthermore,
DFT
calculations
provide
comprehensive
explanation
stereoselectivity
observed
reaction.
ChemistrySelect,
Journal Year:
2024,
Volume and Issue:
9(8)
Published: Feb. 22, 2024
Abstract
Carbenes
are
pivotal
reactive
intermediates
for
accessing
a
wide
range
of
complex
molecules,
which
frequently
used
in
chemical
synthesis
and
medicinal
advancement.
We
have
developed
convenient
approach
to
fluorenes
from
α
‐biaryldiazoacetates
via
low‐energy
blue
light‐induced
photochemical
generation
carbene
intermediate,
where
the
reaction
took
place
at
room
temperature
without
any
catalysts,
bases,
or
oxidants
acetonitrile.
The
present
catalyst‐free
operationally
simple
enables
highly
efficient
annulation
under
mild
conditions.
Tetrahedron Chem,
Journal Year:
2023,
Volume and Issue:
7, P. 100040 - 100040
Published: June 16, 2023
Herein,
we
developed
a
mild
and
efficient
photoredox-enabled
remote
radical
group
migration
with
the
utilization
of
diazoalkanes
as
precursors,
giving
access
to
various
valuable
1,7-dicarbonlys
in
moderate
good
yields.
A
diverse
set
migrating
groups,
including
benzothiazole,
benzothiophene,
pyrazine,
pyridine,
thiazole,
thiophene
nitrile
were
well
tolerated.
Furthermore,
facile
synthesis
1,8-dicarbonyl
compound,
scale-up
reaction
useful
synthetic
transformation
further
proved
method
attractive
valuable.
Asian Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
12(8)
Published: July 11, 2023
Abstract
A
visible‐light‐promoted
O−H
functionalization
of
4‐hydroxycoumarins
with
α‐diazo
esters
was
developed
for
the
synthesis
4‐hydroxycoumarin
ethers
under
photocatalyst‐free
conditions.
Moreover,
three‐component
reaction
4‐hydroxycoumarins,
and
THF
formed
a
series
ether
derivatives
alkoxyl
spacers
in
yields
up
to
91%.
The
above
mentioned
solvent‐dependent
carbene
insertion
transformations
were
conducted
extremely
mild
conditions
tolerance
moisture
oxygen.
The Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
89(1), P. 665 - 675
Published: Dec. 20, 2023
A
gentle
and
effective
method
for
the
photocatalytic
dual
functionalization
of
allenes
with
high
regio-
stereoselectivity
using
a
nonmetallic
catalyst
is
described.
Inexpensive
easily
available
sulfinates
TMSN3
were
employed
as
sulfone
azido
sources,
respectively.
The
characterized
by
satisfactory
substrate
compatibility
tolerance
toward
functional
groups.
straightforward
initial
mechanistic
experiments
suggested
that
reaction
could
follow
radical
pathway.
synthesis
vinylsulfone
azide
derivatives
presented
here
offers
promising
scaffold
future
development
vinyl
sulfone-based
drugs
bioorthogonal
reagents.
