Inorganic Chemistry,
Год журнала:
2024,
Номер
64(1), С. 662 - 673
Опубликована: Дек. 27, 2024
Unsymmetrical
bis-cyclometalated
dicarboxylato
complexes
(OC-6-32)-[Pt(tpy)2(O2CR)2]
[tpy
=
cyclometalated
2-(p-tolyl)pyridine,
R
t-Bu
(1),
Me
(2),
Ph
(3),
CF3
(4)],
are
obtained
from
the
reaction
of
cis-[Pt(tpy)2]
with
appropriate
PhI(O2CR)2
reagent.
Treatment
this
type
different
carboxylates
(R'CO2–)
results
in
formation
mixed-carboxylato
derivatives,
namely
(OC-6-43)-[Pt(tpy)2(O2CMe)(O2CR′)]
[R′
(5),
(6),
(7)],
(OC-6-34)-[Pt(tpy)2(O2CCF3)(O2CR′)]
(8),
(9),
(10)],
and
(OC-6-34)-[Pt(tpy)2(O2C-t-Bu)(O2CMe)]
(11).
Irradiation
1–3
5–11
UV
light
(365
nm)
MeCN
gives
5-methyl-2-(2-pyridyl)phenyl
pivalate
(12),
acetate
(13)
or
benzoate
(14)
as
major
photoproduct
most
complexes,
resulting
a
reductive
C–O
coupling
between
tpy
ligand
carboxylato
ligand.
Cyclometalation
12–14
at
ensuing
Pt(II)
species
to
produce
cis-[Pt(tpy)(tpyO2CR/R′)],
reduction
isomerization
(OC-6-33)-[Pt(tpy)2(O2CR/R′)2]
identified
secondary
processes
cases.
In
contrast,
complex
4
exclusively
photoisomerizes
(OC-6-33)-[Pt(tpy)2(O2CCF3)2]
(4′).
The
couplings
favored
for
electron-rich
ligands
occur
predominantly
trans
N.
Consistent
this,
computational
study
reveals
that
lowest
singlet
triplet
LMCT
excited
states
result
electronic
transitions
dσ*
orbital
distributed
along
N–Pt–O
axis,
which
would
trigger
observed
processes.
Green Chemistry,
Год журнала:
2024,
Номер
26(14), С. 8360 - 8366
Опубликована: Янв. 1, 2024
A
photoinduced
palladium-catalyzed
generation
of
phosphorus
radicals
using
Cl–phosphine
oxides
and
Cl–phosphates
is
realized
to
achieve
formal
P-Heck
reaction,
C–H
phosphinylation
heteroaromatics
difunctionalization
alkenes.
Organic Letters,
Год журнала:
2024,
Номер
26(27), С. 5719 - 5724
Опубликована: Июнь 28, 2024
A
novel
photocatalytic
palladium-induced
6-endo-selective
alkyl
Heck
reaction
of
unactivated
iodides
and
bromides
has
been
described.
This
strategy
facilitates
the
gentle
efficient
synthesis
a
variety
5-phenyl-1,2,3,6-tetrahydropyridine
derivatives.
It
demonstrates
broad
substrate
tolerance
excellent
6-endo
selectivity.
Unlike
high-temperature
requirements
traditional
reactions,
this
transformation
efficiently
proceeds
at
room
temperature
shows
significant
promise
for
industrial-scale
applications.
Mechanistic
investigations
reveal
that
via
hybrid
palladium–radical
process.
Angewandte Chemie,
Год журнала:
2024,
Номер
136(26)
Опубликована: Апрель 20, 2024
Abstract
Photoinduced
Pd‐catalyzed
bisfunctionalization
of
butadienes
with
a
readily
available
organic
halide
and
nucleophile
represents
an
emerging
attractive
method
to
assemble
versatile
alkenes
bearing
various
functional
groups
at
the
allylic
position.
However,
enantiocontrol
and/or
diastereocontrol
in
C−C
or
C−X
bond‐formation
step
have
not
been
solved
due
open‐shell
process.
Herein,
we
present
cascade
asymmetric
dearomatization
reaction
indoles
via
photoexcited
1,2‐biscarbonfunctionalization
1,3‐butadienes,
wherein
control
on
both
electrophile
part
is
achieved
for
first
time
photoinduced
butadienes.
This
delivers
structurally
novel
chiral
spiroindolenines
two
contiguous
stereogenic
centers
high
diastereomeric
ratios
(up
>20
:
1
dr)
good
excellent
enantiomeric
97
3
er).
Experimental
computational
studies
mechanism
confirmed
radical
pathway
involving
excited‐state
palladium
catalysis.
The
alignment
non‐covalent
interactions
between
substrate
catalyst
were
found
be
essential
stereocontrol.
We
have
effectively
utilized
cost-effective
2-bromoanthraquinone
as
a
photocatalyst
to
develop
an
efficient
and
environmentally
friendly
method
for
producing
o-hydroxy
lactones
under
mild
visible
light
irradiation.
Importantly,
this
protocol
only
relies
on
oxygen
oxidant,
completely
eliminating
the
need
additional
chemical
reagents
showcasing
sustainable
approach
transformation.
Operating
at
room
temperature,
we
mixed
solvent
system
of
DMF
CHCl3,
which
greatly
facilitated
selective
conversion
various
2-vinylbenzoic
acids
carboxylic
functional
o-hydroxyl
lactones.
The
process
also
exhibited
excellent
diastereoselectivity.
Moreover,
versatile
strategy
is
compatible
with
wide
range
biologically
active
complex
molecules,
offering
new
opportunities
late-stage
structural
modifications
these
compounds.
Inorganic Chemistry,
Год журнала:
2024,
Номер
64(1), С. 662 - 673
Опубликована: Дек. 27, 2024
Unsymmetrical
bis-cyclometalated
dicarboxylato
complexes
(OC-6-32)-[Pt(tpy)2(O2CR)2]
[tpy
=
cyclometalated
2-(p-tolyl)pyridine,
R
t-Bu
(1),
Me
(2),
Ph
(3),
CF3
(4)],
are
obtained
from
the
reaction
of
cis-[Pt(tpy)2]
with
appropriate
PhI(O2CR)2
reagent.
Treatment
this
type
different
carboxylates
(R'CO2–)
results
in
formation
mixed-carboxylato
derivatives,
namely
(OC-6-43)-[Pt(tpy)2(O2CMe)(O2CR′)]
[R′
(5),
(6),
(7)],
(OC-6-34)-[Pt(tpy)2(O2CCF3)(O2CR′)]
(8),
(9),
(10)],
and
(OC-6-34)-[Pt(tpy)2(O2C-t-Bu)(O2CMe)]
(11).
Irradiation
1–3
5–11
UV
light
(365
nm)
MeCN
gives
5-methyl-2-(2-pyridyl)phenyl
pivalate
(12),
acetate
(13)
or
benzoate
(14)
as
major
photoproduct
most
complexes,
resulting
a
reductive
C–O
coupling
between
tpy
ligand
carboxylato
ligand.
Cyclometalation
12–14
at
ensuing
Pt(II)
species
to
produce
cis-[Pt(tpy)(tpyO2CR/R′)],
reduction
isomerization
(OC-6-33)-[Pt(tpy)2(O2CR/R′)2]
identified
secondary
processes
cases.
In
contrast,
complex
4
exclusively
photoisomerizes
(OC-6-33)-[Pt(tpy)2(O2CCF3)2]
(4′).
The
couplings
favored
for
electron-rich
ligands
occur
predominantly
trans
N.
Consistent
this,
computational
study
reveals
that
lowest
singlet
triplet
LMCT
excited
states
result
electronic
transitions
dσ*
orbital
distributed
along
N–Pt–O
axis,
which
would
trigger
observed
processes.
