ACS Catalysis,
Journal Year:
2021,
Volume and Issue:
11(5), P. 2992 - 2998
Published: Feb. 22, 2021
The
concept
of
"umpolung"
reactivity
π-allylmetal
complexes
has
been
developed
as
a
powerful
method
for
the
allylation
aldehydes.
This
paper
describes
photocatalytic
umpolung
strategy
synthesis
nucleophilic
allylcobalt
through
single-electron-transfer
(SET)
process.
enables
metallaphotoredox
carbonyls
with
allyl
acetate
using
organic
N,N-diisopropylethylamine
terminal
reductant
bypassing
use
stoichiometric
amount
metals.
Ultraviolet–visible
spectroscopy
was
used
to
monitor
redox
changes
cobalt
in
reaction.
ACS Catalysis,
Journal Year:
2020,
Volume and Issue:
10(8), P. 4710 - 4716
Published: March 24, 2020
An
enantioselective
and
branch-regioselective
α-allylation
of
N-methyl
anilines
under
dual
palladium/photoredox
catalysis
is
described.
Readily
available
are
used
as
formal
"hard"
alkyl
nucleophiles
without
preactivation.
Acetic
acid
the
only
side
product,
which
leads
to
a
high
atom
economy
this
reaction.
This
protocol
shows
good
functional
group
tolerance
broad
scope.
A
range
chiral
homoallylic
amines
were
prepared
in
moderate
yields
(up
76%)
excellent
regioselectivities
(B:L
>
95:5
all
cases)
enantioselectivities
96%
ee)
mild
reaction
conditions.
Organic Letters,
Journal Year:
2020,
Volume and Issue:
22(9), P. 3519 - 3523
Published: April 17, 2020
Cobalt-catalyzed
highly
branched-
and
enantioselective
allylic
alkylation
of
malononitriles
has
been
developed.
Chiral
γ,δ-unsaturated
could
be
synthesized
with
>20:1
branched/linear
regioselectivity
up
to
99%
enantiomeric
excess
from
easily
accessible
racemic
carbonates
under
mild
reaction
conditions.
The
electron-rich
sterically
less
hindered
bisoxazolinephosphine
ligand
is
essential
realize
the
high
reactivity
in
carbon–carbon
bond
formation
process.
ACS Catalysis,
Journal Year:
2021,
Volume and Issue:
11(9), P. 5287 - 5293
Published: April 16, 2021
An
effective
regiodivergent
synthesis
toward
1-
and
3-thiosugars
was
achieved
through
palladium
cobalt
catalysis,
respectively.
β-1-Thiosugars
were
obtained
from
3,4-O-carbonate-glycals
various
thiols
catalyzed
by
Pd2(dba)3
in
good
yields
with
exclusive
stereoselectivity
chemoselectivity,
while
only
(3S)-3-thiosugars
generated
via
Co(BF4)2.
Experiments
DFT
calculations
supported
the
proposed
mechanism
that
thiol
moiety
preferred
to
form
a
hydrogen
bond
C4-oxygen
top-face
Pd
conditions
but
would
coordinate
bottom-face
Co
conditions.
The
difference
between
Pd/Co–C1
Pd/Co–C3
lengths
of
key
intermediates
provided
further
insights
into
1,3-regioselectivity.
ACS Catalysis,
Journal Year:
2021,
Volume and Issue:
11(5), P. 2992 - 2998
Published: Feb. 22, 2021
The
concept
of
"umpolung"
reactivity
π-allylmetal
complexes
has
been
developed
as
a
powerful
method
for
the
allylation
aldehydes.
This
paper
describes
photocatalytic
umpolung
strategy
synthesis
nucleophilic
allylcobalt
through
single-electron-transfer
(SET)
process.
enables
metallaphotoredox
carbonyls
with
allyl
acetate
using
organic
N,N-diisopropylethylamine
terminal
reductant
bypassing
use
stoichiometric
amount
metals.
Ultraviolet–visible
spectroscopy
was
used
to
monitor
redox
changes
cobalt
in
reaction.
