Diaryliodonium
salts
are
bench
stable
aryl
radical
precursors.
While
photocatalysts
generally
responsible
for
generation,
recent
reports
have
emerged
exhibiting
photocatalyst-free
generation
using
select
Lewis
bases
as
activators.
Herein,
we
demonstrate
1)
the
ability
of
numerous
to
enable
light-driven
and
2)
these
radicals
can
be
captured
by
transition-metals
coupling
reactions.
These
results
first
step
toward
developing
new
organometallic
reactions
without
photocatalysts.
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
14(24), P. 18896 - 18906
Published: Dec. 12, 2024
There
is
a
scarcity
of
general
strategies
for
the
site-selective
α–Csp3–H
arylation
glycine
derivatives
to
synthesize
nonproteinogenic
α-arylglycines
that
occur
frequently
in
commercial
drugs
and
bioactive
molecules.
We
disclose
copper-photoredox-catalyzed
using
diaryliodonium
reagents
(DAIRs)
as
arylating
agents.
This
strategy
harnesses
underexplored
ability
DAIRs
serve
agents
under
visible-light
irradiation
copper
salts
photocatalysts.
The
method
applies
glycine-selective
C–H
peptides
with
electronically
structurally
diverse
DAIRs.
Moreover,
we
demonstrate
photoinduced
copper-catalyzed
single
electron
transfer
(SET)
can
be
coupled
halogen
atom
(XAT)
process
presence
alkyl
iodides
accomplish
alkylation
glycines
peptides.
In
this
synergistic
SET/XAT
approach,
phenyl
radicals
generated
from
diphenyl
iodonium
triflate
mediate
XAT
generate
iodides.
Both
these
methods
operate
mild
conditions
exhibit
broad
scope
appreciable
functional
group
tolerance.
Overall,
divergent
toolbox
presented
here
facilitate
access
various
alkylated
arylated
enable
bioconjugation
between
drug
Organic Letters,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 27, 2024
We
present
an
iron-photocatalyzed
decarboxylative
alkylation
strategy
involving
carboxylic
acids
and
Morita–Baylis–Hillman
(MBH)
acetates
to
synthesize
E-type
tri-
tetrasubstituted
alkenes
with
moderate
excellent
stereoselectivity
(E/Z
ratio
up
>19:1).
This
method
is
applicable
a
broad
range
of
structurally
diverse
primary,
secondary,
tertiary
alkyl
acids,
as
well
complex
pharmaceutical
natural
achieving
efficient
various
MBH
under
mild
conditions
(>60
examples,
yields
96%).
approach
offers
powerful
for
streamlined
alkylation.
ChemPhotoChem,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 24, 2024
Abstract
Direct
functionalization
of
C−H
bonds
is
the
most
expeditious
strategy
to
build
complexity
into
organic
molecules.
Unfortunately,
Pd‐catalyzed
arylation
strategies
require
high
temperatures
and/or
stoichiometric
oxidants.
The
discovery
metallaphotoredox
in
2011
forged
a
new
approach
achieve
metal
catalyzed
at
room
temperature.
Since
this
discovery,
reports
still
use
explosive
diazonium
salts
as
aryl
radical
precursors.
Alternatively,
single
report
uses
bench‐stable
diaryliodonium
salts,
albeit
with
an
Ir‐based
photocatalyst.
In
study,
we
develop
organophotoredox
manifold
that
enables
numerous
N
‐aryl
amide
substrates.
results
present
are
expected
revitalize
temperature
arylations
wide‐ranging
classes
bonds.
Abstract
A
photocatalytic
methodology
has
been
devised
for
the
stereoselective
construction
of
trisubstituted
alkenes
incorporating
3,3‐difluoro‐γ‐lactams
in
17–93%
yields
via
a
radical
cascade
process
utilizing
MBH
acetates
and
N
‐allylbromodifluoroacetamides
as
starting
materials.
The
reaction
mechanism
involves
single‐electron
transfer,
5
‐
exo
trig
cyclization,
addition,
elimination
fashion.
Diaryliodonium
salts
are
bench
stable
aryl
radical
precursors.
While
photocatalysts
generally
responsible
for
generation,
recent
reports
have
emerged
exhibiting
photocatalyst-free
generation
using
select
Lewis
bases
as
activators.
Herein,
we
demonstrate
1)
the
ability
of
numerous
to
enable
light-driven
and
2)
these
radicals
can
be
captured
by
transition-metals
coupling
reactions.
These
results
first
step
toward
developing
new
organometallic
reactions
without
photocatalysts.
