Journal of the American Chemical Society,
Journal Year:
2018,
Volume and Issue:
140(46), P. 15586 - 15590
Published: Nov. 5, 2018
We
disclose
unprecedented
synergistic
bimetallic
Ni/Ag
and
Ni/Cu
catalysts
for
regioselective
γ,δ-diarylation
of
unactivated
alkenes
in
simple
ketimines
with
aryl
halides
arylzinc
reagents.
The
synergy,
which
generates
cationic
Ni(II)
species
during
reaction,
promotes
migratory
insertion
transmetalation
steps
suppresses
β-H
elimination
cross-coupling,
the
major
side
reactions
that
cause
serious
problems
alkene
difunctionalization.
This
diarylation
reaction
proceeds
at
remote
locations
to
imines
afford,
after
H+
workup,
diversely
substituted
γ,δ-diaryl
ketones
are
otherwise
difficult
access
readily
existing
methods.
ACS Catalysis,
Journal Year:
2020,
Volume and Issue:
10(15), P. 8542 - 8556
Published: July 2, 2020
1,2-Dicarbofunctionalization
of
alkenes
has
emerged
as
an
efficient
synthetic
strategy
for
preparing
substituted
molecules
by
coupling
readily
available
with
electrophiles
and/or
nucleophiles.
Nickel
complexes
serve
effective
catalysts
owing
to
their
tendency
undergo
facile
oxidative
addition
and
slow
β-hydride
elimination,
capability
access
both
two-electron
radical
pathways.
Two-component
alkene
functionalization
reactions
have
achieved
high
chemo-,
regio-,
stereoselectivities
tethering
one
the
partners
substrate.
Three-component
reactions,
however,
often
incorporate
directing
groups
control
selectivity.
Only
a
few
examples
directing-group-free
difunctionalizations
unactivated
been
reported.
Therefore,
great
opportunities
exist
development
three-component
difunctionalization
broad
substrate
scopes
tunable
stereoselectivities.
Chemical Society Reviews,
Journal Year:
2020,
Volume and Issue:
49(6), P. 1790 - 1811
Published: Jan. 1, 2020
Vicinal
alkene
carboamination
is
a
highly
efficient
and
practical
synthetic
strategy
for
the
straightforward
preparation
of
diverse
valuable
amine
derivatives
starting
from
simple
compounds.
During
last
decade
that
approach
has
found
continuous
research
interests
various
methods
have
been
developed
using
transition-metal
catalysis.
Driven
by
renaissance
radical
chemistry,
intermolecular
comprising
C-C
bond
C-N
forming
step
intensively
investigated
recently
culminating
in
novel
strategies
improved
protocols
which
complement
existing
methodologies.
Radical
can
be
achieved
via
three
different
reaction
modes.
Such
cascades
proceed
through
N-radical
addition
to
an
with
subsequent
formation
leading
2,1-carboamination
products.
Alternatively,
installed
prior
initial
C-radical
β-amination
resulting
1,2-carboamination.
The
third
mode
comprises
single
electron
oxidation
corresponding
cation
gets
trapped
N-nucleophile
cascade
terminated
formation.
In
this
review,
conceptual
approaches
will
discussed
examples
recent
literature
presented.
Further,
reader
get
insights
into
mechanism
transformations.
Accounts of Chemical Research,
Journal Year:
2020,
Volume and Issue:
53(4), P. 906 - 919
Published: April 2, 2020
ConspectusNickel
complexes
exhibit
distinct
properties
from
other
group
10
metals,
including
a
small
nuclear
radius,
high
paring
energy,
low
electronegativity,
and
redox
potentials.
These
enable
Ni
catalysts
to
accommodate
stabilize
paramagnetic
intermediates,
access
radical
pathways,
undergo
slow
β-H
elimination.
Our
research
program
investigates
how
each
of
these
fundamental
attributes
impact
the
catalytic
Ni,
in
particular
context
alkene
functionalization.Alkenes
are
versatile
functional
groups,
but
stereoselective
carbofunctionalization
reactions
alkenes
have
been
underdeveloped.
This
challenge
may
derive
difficulty
controlling
selectivity
via
traditional
two-electron
migratory
insertion
pathways.
could
lead
different
stereodetermining
steps
mechanisms,
allowing
molecular
scaffolds
that
otherwise
difficult
prepare.
For
example,
an
asymmetric
diarylation
reaction
developed
by
our
relies
upon
Ni(III)
intermediates
control
enantioselectivity
give
library
chiral
α,α,β-triarylethane
molecules
with
biological
activity.Mechanistic
studies
on
two-component
reductive
1,2-difunctionalization
shed
light
origin
cross-electrophile
selectivity,
as
C
sp2
sp3
electrophiles
independently
activated
at
Ni(I)
respectively.
Catalyst
reduction
has
identified
be
turnover-limiting
step
this
system.
A
closer
investigation
formation
using
(Xantphos)Ni(I)Ar
model
complex
reveals
initiates
concerted
halogen-abstraction
pathway.The
potentials
allowed
us
develop
reductive,
trans-selective
diene
cyclization,
wherein
classic
mechanism
operates
Ni(I)/Ni(III)
platform,
accounting
for
chemo-
stereoselectivity.
found
applications
efficient
synthesis
pharmaceutically
relevant
molecules,
such
3,4-dimethylgababutin.The
tendency
one-electron
processes
prompted
explore
dinuclear
Ni-mediated
bond
formations.
provide
insight
into
Ni–Ni
bonding
two
metal
centers
react
cooperatively
promote
C–C,
C–X,
N–N
forming
elimination.Finally,
isolation
β-agostic
Pd
X-ray
neutron
diffraction
characterization
highly
reactive
molecules.
The
parameters
serve
unambiguous
evidence
interactions
help
rationalize
slower
elimination
relative
Pd.
Overall,
elucidated
several
contexts.
Greater
mechanistic
understanding
facilitates
catalyst
design
helps
reactivity
Ni-catalyzed
functionalization
reactions.
Journal of the American Chemical Society,
Journal Year:
2018,
Volume and Issue:
140(39), P. 12364 - 12368
Published: Sept. 20, 2018
A
Ni-catalyzed
enantioselective
reductive
diarylation
of
activated
alkenes
by
domino
cyclizative/cross-coupling
two
aryl
bromides
is
developed.
This
reaction
proceeds
under
very
mild
conditions
and
shows
broad
substrate
scope,
without
requiring
the
use
preformed
organometallic
reagents.
Moreover,
this
approach
provides
direct
access
to
various
bis-heterocycles
bearing
all-carbon
quaternary
centers
in
synthetically
useful
yields
(up
81%)
with
excellent
enantioselectivity
(>30
examples,
90–99%
ee).
Angewandte Chemie International Edition,
Journal Year:
2019,
Volume and Issue:
58(10), P. 3198 - 3202
Published: Jan. 25, 2019
Abstract
A
nickel‐catalyzed
asymmetric
diarylation
reaction
of
vinylarenes
enables
the
preparation
chiral
α,α,β‐triarylated
ethane
scaffolds,
which
exist
in
a
number
biologically
active
molecules.
The
use
reducing
conditions
with
aryl
bromides
as
coupling
partners
obviates
need
for
stoichiometric
organometallic
reagents
and
tolerates
broad
range
functional
groups.
application
an
N
‐oxyl
radical
ligand
to
nickel
catalyst
represents
novel
approach
facilitate
cross‐coupling
reactions.
Journal of the American Chemical Society,
Journal Year:
2020,
Volume and Issue:
142(21), P. 9604 - 9611
Published: May 11, 2020
A
nickel-catalyzed,
enantioselective,
three-component
fluoroalkylarylation
of
unactivated
alkenes
with
aryl
halides
and
perfluoroalkyl
iodides
has
been
described.
This
cross-electrophile
coupling
protocol
utilizes
a
chiral
nickel/BiOx
system
as
well
pendant
chelating
group
to
facilitate
the
challenging
three-component,
asymmetric
difunctionalization
alkenes,
providing
direct
access
valuable
β-fluoroalkyl
arylalkanes
high
efficiency
excellent
enantioselectivity.
The
mild
conditions
allow
for
broad
substrate
scope
good
functional
toleration.
Chemical Society Reviews,
Journal Year:
2021,
Volume and Issue:
50(19), P. 10836 - 10856
Published: Jan. 1, 2021
The
catalytic
dicarbofunctionalization
of
unsaturated
π
bonds
represents
a
powerful
platform
for
the
rapid
construction
complex
motifs.
Despite
remarkable
progress,
novel
and
efficient
methods
achieving
such
transformations
under
milder
conditions
with
chemo-,
regio-,
stereoselectivity
still
remain
significant
challenge;
thus,
their
development
is
highly
desirable.
Recently,
merging
nickel
catalysis
radical
chemistry
offers
new
benign
unprecedented
reactivity
selectivity.
In
this
review,
we
summarize
recent
advances
in
area
by
underpinning
domino
involving
capture
to
provide
clear
overview
reaction
designs
mechanistic
scenarios.
Accounts of Chemical Research,
Journal Year:
2021,
Volume and Issue:
54(17), P. 3415 - 3437
Published: Aug. 12, 2021
ConspectusRecently,
alkene
dicarbofunctionalization,
i.e.,
the
powerful
organic
synthesis
method
of
difunctionalization
with
two
carbon
sources,
emerged
as
a
formidable
reaction
immense
promise
to
synthesize
complex
molecules
expeditiously
from
simple
chemicals.
This
is
generally
achieved
transition
metals
(TMs)
through
interception
by
sources
an
alkylmetal
[β-H–C(sp3)–[M]]
species,
key
intermediate
prone
undergo
rapid
β-H
elimination.
Related
prior
reports,
since
Paolo
Chiusoli
and
Catellani's
work
in
1982
[
Tetrahedron
Lett.
1982,
23,
4517],
have
used
bicyclic
disubstituted
terminal
alkenes,
wherein
elimination
avoided
geometric
restriction
or
complete
lack
β-H's.
With
reasoning
that
β-H–C(sp3)–[M]
intermediates
could
be
rendered
amenable
use
first
row
late
TMs
formation
coordination-assisted
transient
metallacycles,
these
strategies
were
implemented
address
problem
dicarbofunctionalization
reactions.Because
catalyze
C(sp3)–C(sp3)
coupling,
Cu
Ni
anticipated
impart
sufficient
stability
intermediates,
generated
catalytically
upon
carbometalation,
for
their
subsequent
electrophiles/nucleophiles
three-component
reactions.
Additionally,
such
innate
property
enable
coupling
partners
entropically
driven
cyclization/coupling
The
cyclometalation
concept
stabilize
intractable
was
hypothesized
when
reactions
performed.
idea
curtail
founded
Whitesides's
J.
Am.
Chem.
Soc.
1976,
98,
6521]
observation
metallacycles
much
slower
than
acyclic
alkylmetals.In
this
Account,
examples
demonstrate
catalysts
alkenylzinc
reagents,
alkyl
halides,
aryl
halides
afford
carbo-
heterocycles.
In
addition,
forming
nickellacycles
enabled
regioselective
performance
various
alkenyl
compounds.
situ
[M]-H
alkenes
after
induced
unprecedented
metallacycle
contraction
process,
which
six-membered
metal-containing
rings
shrank
five-membered
cycles,
allowing
creation
new
carbon–carbon
bonds
at
allylic
(1,3)
positions.
Applications
are
discussed.
Journal of the American Chemical Society,
Journal Year:
2019,
Volume and Issue:
141(41), P. 16197 - 16201
Published: Sept. 29, 2019
A
catalytic
deaminative
alkylation
of
unactivated
olefins
is
described.
The
protocol
characterized
by
its
mild
conditions,
wide
scope,
including
the
use
ethylene
as
substrate,
and
exquisite
site-selectivity
pattern
for
both
α-olefins
internal
olefins,
thus
unlocking
a
new
platform
to
forge
sp3-sp3
linkages,
even
in
context
late-stage
functionalization.
Chinese Journal of Chemistry,
Journal Year:
2020,
Volume and Issue:
38(11), P. 1371 - 1394
Published: June 16, 2020
As
a
straightforward
strategy
for
rapidly
increasing
molecular
complexity,
dicarbofunctionalization
of
alkenes
has
attracted
substantial
interests
organic
synthesis,
medicine
chemistry,
and
materials
science.
Nickel‐catalyzed
cascade
dicarbofunctionalizations
have
been
flourished
in
this
area
recently,
nickel‐mediated
radical
pathways
particularly
offer
new
opportunities
conjunctive
cross‐couplings
with
alkyl
coupling
partners.
Herein,
we
give
comprehensive
review
nickel‐catalyzed
through
historical
perspective,
including
intermolecular
three‐component
reactions
intramolecular
reactions.
Among
the
discussed
review,
carbometallation/cross‐coupling
process
addition/cross‐coupling
are
two
major
alkenes.
The
oxidative
cyclization
1,2‐metallate
shift
processes
also
selectively
discussed.
These
methods
overcome
limitations
associated
using
noble
metals
field,
providing
an
efficient
access
to
structurally
diversified
molecules.