Chemistry - A European Journal,
Год журнала:
2023,
Номер
29(58)
Опубликована: Июль 19, 2023
In
recent
years,
there
has
been
a
concerted
drive
to
develop
methods
that
are
greener
and
more
sustainable.
Being
an
earth-abundant
transition
metal,
cobalt
offers
attractive
substitute
for
commonly
employed
precious
metal
catalysts,
though
reactions
engaging
still
less
developed.
Herein,
we
report
method
achieve
the
decarboxylative
allylation
of
nitrophenyl
alkanes,
nitroalkanes,
ketones
employing
cobalt.
The
reaction
allows
formation
various
substituted
allylated
products
in
moderate-excellent
yields
with
broad
scope.
Additionally,
synthetic
potential
methodology
is
demonstrated
by
transformation
into
versatile
heterocyclic
motifs.
Mechanistic
studies
revealed
situ
activation
Co(II)/dppBz
precatalyst
carboxylate
salt
generate
Co(I)-species,
which
presumed
be
active
catalyst.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(33)
Опубликована: Май 31, 2024
Catalytic
enantioselective
alkenylation
of
aldehydes
with
easily
accessible
alkenyl
halides
promoted
by
a
chiral
cobalt
complex
derived
from
newly
developed
tridentate
bisoxazolinephosphine
is
presented.
Such
processes
represent
an
unprecedented
reaction
pathway
for
catalysis
and
general
approach
that
enable
rapid
construction
highly
diversified
enantioenriched
allylic
alcohols
containing
1,1-,
1,2-disubstituted
trisubstituted
alkene
as
well
axial
stereogenicity
in
up
to
99
%
yield
:
1
er
without
the
need
preformation
alkenyl-metal
reagents.
DFT
calculations
revealed
origin
enantioselectivity.
Organic Letters,
Год журнала:
2020,
Номер
22(24), С. 9456 - 9461
Опубликована: Дек. 2, 2020
The
first
highly
regio-
and
enantioselective
synthesis
of
3-allylindolizines
has
been
developed
by
the
sequential
Rh-catalyzed
asymmetric
allylation
Tschitschibabin
reaction.
Above
20:1
branch/linear
ratio,
up
to
a
96%
yield
99%
ee
could
be
obtained
with
help
tert-butyl-substituted
chiral
bisoxazolinephosphine
ligand.
In
situ
generated
nucleophilic
2-alkylpyridinium
ylides
are
utilized
undergo
alkylation
reaction
before
cyclization.
Organic Process Research & Development,
Год журнала:
2020,
Номер
24(11), С. 2428 - 2444
Опубликована: Окт. 30, 2020
This
highlight
is
the
second
installment
of
a
series
highlights
on
nonprecious-metal-catalyzed
reactions
interest
to
pharmaceutical
industry.
Selected
transformations
from
March
June
2020
are
summarized.
Our
goal
facilitate
advancements
in
areas
safer
and
greener
chemical
manufacturing
using
earth-abundant
metals.
ACS Catalysis,
Год журнала:
2023,
Номер
13(3), С. 2156 - 2161
Опубликована: Янв. 25, 2023
The
asymmetric
allylic
alkylation
(AAA)
reaction
using
less
reactive,
stable
sources
is
challenging.
We
achieved
a
nickel(0)-catalyzed
AAA
of
β-dicarbonyl
compounds
under
ambient
conditions
through
unstrained
C–C
bond
activation
2-allylated
2-methylcyclohexane-1,3-dione
derivatives
to
afford
the
corresponding
quaternary
chiral
in
high
yield
with
enantioselectivity.
proceeded
almost
irreversibly
due
low
solubility
side-product,
2-methylcyclohexane-1,3-dione.
Control
experiments
and
DFT
calculations
allowed
for
elucidating
mechanism
Ni(0)-(S)-tol-MeO-BIPHEP
catalyst
system;
turnover
limiting
step
formation,
reverse
requires
7.6
kcal
mol–1
higher
energy
than
forward
reaction.
Chemistry - A European Journal,
Год журнала:
2020,
Номер
27(10), С. 3457 - 3462
Опубликована: Дек. 2, 2020
Abstract
The
control
of
C3/N1
chemoselectivity
in
indole
alkylation
with
the
same
electrophiles
is
still
challenging.
An
Rh/bisoxazolinephosphane‐catalyzed
chemodivergent
regio‐
and
enantioselective
allylic
indoles
was
developed.
Chiral
C3‐
N1‐allylindoles
can
be
selectively
obtained
high
branched/linear
ratio
up
to
99
%
ee
by
changing
counteranion
Rh,
carbonate,
reaction
temperature,
ligand.
Organic Letters,
Год журнала:
2020,
Номер
22(12), С. 4686 - 4691
Опубликована: Май 28, 2020
A
new
catalyst
system
based
on
Co(OAc)2/bisoxazolinephosphine
has
been
developed
to
catalyze
the
direct
addition
of
terminal
alkynes
isatins
under
base-free
conditions.
Chiral
propargyl
alcohols
with
an
oxindole
skeleton
could
be
prepared
in
up
99%
yield
and
ee
help
chiral
tridentate
ligand.
variety
functionalized
aliphatic
or
aromatic
were
utilized
this
method,
gram-scale
synthesis
achieved
1
mol
%
catalyst.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 12, 2024
Enantioenriched
unnatural
amino
acids
represent
a
prevalent
motif
in
organic
chemistry,
with
profound
applications
biochemistry,
medicinal
and
materials
science.
Herein,
we
report
cobalt-catalyzed
aza-Barbier
reaction
of
dehydroglycines
unactivated
alkyl
halides
to
afford
α-amino
esters
high
enantioselectivity.
This
catalytic
reductive
alkylative
addition
protocol
circumvents
the
use
moisture-,
air-sensitive
organometallic
reagents,
stoichiometric
chiral
auxiliaries,
enabling
conversion
variety
primary,
secondary,
even
tertiary
α-alkyl-amino
under
mild
conditions,
thus
leading
broad
functional
group
tolerance.
The
expedient
access
biologically
active
motifs
demonstrates
practicality
this
by
reducing
number
synthetic
steps
enhancing
efficiency.
Organic Letters,
Год журнала:
2023,
Номер
25(20), С. 3693 - 3697
Опубликована: Май 15, 2023
A
highly
regio-
and
enantioselective
allylic
sulfonylation
has
been
developed
with
rhodium
bisoxazolinephosphine
(NPN*)
ligands
from
racemic
branched
carbonates
readily
available
sulfonyl
hydrazides
under
neutral
conditions.
Branch-selective
sulfones
a
>20:1
branch:linear
ratio
>99%
ee
could
be
synthesized
in
≤96%
yield.
Both
Z
E
linear
also
converted
into
the
same
chiral
high
enantioselectivities.
ACS Catalysis,
Год журнала:
2023,
Номер
13(8), С. 5482 - 5490
Опубликована: Апрель 7, 2023
Abnormal
Claisen
rearrangement
of
phenyl
allyl
ether
with
the
γ-alkyl
group
is
longstanding.
However,
asymmetric
version
this
named
reaction
has
never
been
reported.
Herein,
a
highly
regio-
and
enantioselective
allylic
alkylation
4-hydroxycoumarin
stereospecific
Conia-ene/ene
sequence
developed
as
formal
abnormal
rearrangement.
Chiral
4-hydroxycoumarins
3-allyl
groups
could
be
synthesized
in
up
to
95%
yield
96%
ee
under
catalysis
Rh
chiral
bioxazolinephosphine
ligand.
Experimental
density
functional
theory
calculation
investigations
support
that
based
on
reversible
formation
kinetically
favored
cis-disubstituted
spirocyclopropane
intermediate.
