Stereodivergent
dual
catalysis
has
emerged
as
a
powerful
tool
to
selectively
prepare
all
four
stereoisomers
in
molecules
containing
two
chiral
centers
from
common
starting
materials.
Most
processes
involve
the
use
of
substrates,
and
it
remains
challenging
catalyst
approaches
generate
having
three
newly
formed
stereocenters
with
high
diastereo-
enantioselectivity.
Here
we
report
multicomponent,
stereodivergent
method
for
synthesis
targets
contiguous
by
combination
enantioselective
Rh-catalyzed
conjugate
addition
Ir-catalyzed
allylic
alkylation
methodologies.
Both
cyclic
acyclic
,-unsaturated
ketones
undergo
-arylation
using
aryl
boron
reagents
form
an
enolate
nucleophile
that
can
be
subsequently
allylated
at
-position.
The
reactions
proceed
generally
>95%
ee
>90:10
dr.
Epimerization
-carbonyl
center
enables
preparation
any
eight
possible
materials,
demonstrated
cyclohexanone
products.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(10)
Опубликована: Янв. 4, 2023
Herein,
we
report
a
synthesis
of
cyclohexanones
bearing
multi-continuous
stereocenters
by
combining
copper-catalyzed
asymmetric
conjugate
addition
dialkylzinc
reagents
to
cyclic
enones
with
iridium-catalyzed
allylic
substitution
reaction.
Good
excellent
yields,
diastereoselectivity
and
enantioselectivity
can
be
obtained.
Unlike
the
stereodivergent
construction
adjacent
(1,2-position)
reported
in
literature,
current
reaction
achieve
nonadjacent
(1,3-position)
proper
combination
two
chiral
catalysts
different
enantiomers.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(32)
Опубликована: Июнь 15, 2023
Abstract
Asymmetric
cross‐couplings
based
on
1,2‐carbon
migration
from
B‐ate
complexes
have
been
developed
efficiently
to
access
valuable
organoboronates.
However,
enantioselective
reactions
triggered
by
1,2‐boron
shift
remained
be
unaddressed
synthetic
challenge.
Here,
Ir‐catalyzed
asymmetric
allylic
alkylation
enabled
was
developed.
In
this
reaction,
we
disclosed
that
excellent
enantioselectivities
were
achieved
through
an
interesting
dynamic
kinetic
resolution
(DKR)
process
of
carbonates
at
the
elevated
temperature.
Notably,
highly
(bis‐boryl)alkenes
array
diversifications
versatile
molecules.
Extensive
experimental
and
computational
studies
conducted
elucidate
reaction
mechanism
DKR
clarify
origin
enantioselectivities.
Nature Communications,
Год журнала:
2023,
Номер
14(1)
Опубликована: Авг. 10, 2023
Catalytic
enantioselective
introduction
of
a
propargyl
group
constitutes
one
the
most
important
carbon-carbon
forming
reactions,
as
it
is
versatile
to
be
transformed
into
diverse
functional
groups
and
frequently
used
in
synthesis
natural
products
biologically
active
molecules.
Stereoconvergent
transformations
racemic
precursors
single
enantiomer
via
radicals
represent
powerful
strategy
provide
new
reactivity.
However,
only
few
Cu-
or
Ni-catalyzed
protocols
have
been
developed
with
limited
reaction
modes.
Herein,
photoredox/cobalt-catalyzed
regio-,
diastereo-
addition
aldehydes
presented,
enabling
construction
broad
scope
homopropargyl
alcohols
that
are
otherwise
difficult
access
high
efficiency
stereoselectivity
from
carbonates.
Mechanistic
studies
DFT
calculations
provided
evidence
for
involvement
radicals,
origin
stereoconvergent
process
stereochemical
models.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(16)
Опубликована: Фев. 13, 2024
Abstract
We
report
a
highly
enantioselective
intermolecular
C−H
bond
silylation
catalyzed
by
phosphoramidite‐ligated
iridium
catalyst.
Under
reagent‐controlled
protocols,
propargylsilanes
resulting
from
C(sp
3
)−H
functionalization,
as
well
the
regioisomeric
and
synthetically
versatile
allenylsilanes,
could
be
obtained
with
excellent
levels
of
enantioselectivity
good
to
control
propargyl/allenyl
selectivity.
In
case
unsymmetrical
dialkyl
acetylenes,
selectivity
for
functionalization
at
less‐hindered
site
was
also
observed.
A
variety
electrophilic
silyl
sources
(R
SiOTf
R
SiNTf
2
),
either
commercial
or
in
situ
‐
generated,
were
used
reagents,
broad
range
simple
functionalized
alkynes,
including
aryl
alkyl
1,3‐enynes,
drug
derivatives
successfully
employed
substrates.
Detailed
mechanistic
experiments
DFT
calculations
suggest
that
an
η
‐propargyl/allenyl
Ir
intermediate
is
generated
upon
π‐complexation‐assisted
deprotonation
undergoes
outer‐sphere
attack
silylating
reagent
give
propargylic
silanes,
latter
step
identified
enantiodetermining
step.
Chemical Science,
Год журнала:
2024,
Номер
15(23), С. 8850 - 8857
Опубликована: Янв. 1, 2024
Cyclopentadienyliron(
ii
)
dicarbonyl
complexes
capable
of
coordinating
to
and
enhancing
the
acidity
a
range
unsaturated
substrates
have
emerged
as
new
class
base-metal
derived
catalysts
for
C–H
functionalization.
Chemical Communications,
Год журнала:
2024,
Номер
60(12), С. 1638 - 1641
Опубликована: Янв. 1, 2024
A
practical
one-pot
catalytic
tandem
multicomponent
allylation
condensation
carbonylation
to
construct
allylhydrazones
and
allyl
acylhydrazones
with
high
atom
economy,
water
as
a
coproduct
excellent
regioselectivity
in
reactions.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(32), С. 22122 - 22128
Опубликована: Авг. 5, 2024
The
discovery
and
utilization
of
main-group
element
catalysts
that
behave
similarly
to
transition
metal
(TM)
complexes
have
become
increasingly
active
areas
investigation
in
recent
years.
Here,
we
report
a
series
Lewis
acidic
bismuth(III)
allow
for
the
catalytic
allylic
C(sp3)–H
functionalization
olefins
via
an
organometallic
complexation-assisted
deprotonation
mechanism
generate
products
containing
new
C–C
bonds.
This
heretofore
unexplored
mode
reactivity
was
applied
regioselective
1,4-dienes
allylbenzene
substrates.
Experimental
computational
mechanistic
studies
support
key
steps
proposed
cycle,
including
intermediacy
elusive
Bi–olefin
allylbismuth
species.
Angewandte Chemie,
Год журнала:
2023,
Номер
135(10)
Опубликована: Янв. 4, 2023
Abstract
Herein,
we
report
a
synthesis
of
cyclohexanones
bearing
multi‐continuous
stereocenters
by
combining
copper‐catalyzed
asymmetric
conjugate
addition
dialkylzinc
reagents
to
cyclic
enones
with
iridium‐catalyzed
allylic
substitution
reaction.
Good
excellent
yields,
diastereoselectivity
and
enantioselectivity
can
be
obtained.
Unlike
the
stereodivergent
construction
adjacent
(1,2‐position)
reported
in
literature,
current
reaction
achieve
nonadjacent
(1,3‐position)
proper
combination
two
chiral
catalysts
different
enantiomers.
Chemical Science,
Год журнала:
2023,
Номер
14(34), С. 9191 - 9196
Опубликована: Янв. 1, 2023
Allenenitriles
bearing
different
synthetically
versatile
functional
groups
have
been
prepared
smoothly
from
5-alkynyl
fluorosulfonamides
in
decent
yields
with
an
excellent
chemo-
and
regio-selectivity
under
redox
neutral
conditions.
The
resulting
allenenitriles
can
be
readily
converted
to
useful
functionalized
heterocycles.
Based
on
mechanistic
study,
it
is
confirmed
that
this
the
first
example
of
radical-based
non-activated
propargylic
C-H
functionalization
for
allene
syntheses.
Angewandte Chemie,
Год журнала:
2024,
Номер
136(16)
Опубликована: Фев. 13, 2024
Abstract
We
report
a
highly
enantioselective
intermolecular
C−H
bond
silylation
catalyzed
by
phosphoramidite‐ligated
iridium
catalyst.
Under
reagent‐controlled
protocols,
propargylsilanes
resulting
from
C(sp
3
)−H
functionalization,
as
well
the
regioisomeric
and
synthetically
versatile
allenylsilanes,
could
be
obtained
with
excellent
levels
of
enantioselectivity
good
to
control
propargyl/allenyl
selectivity.
In
case
unsymmetrical
dialkyl
acetylenes,
selectivity
for
functionalization
at
less‐hindered
site
was
also
observed.
A
variety
electrophilic
silyl
sources
(R
SiOTf
R
SiNTf
2
),
either
commercial
or
in
situ
‐
generated,
were
used
reagents,
broad
range
simple
functionalized
alkynes,
including
aryl
alkyl
1,3‐enynes,
drug
derivatives
successfully
employed
substrates.
Detailed
mechanistic
experiments
DFT
calculations
suggest
that
an
η
‐propargyl/allenyl
Ir
intermediate
is
generated
upon
π‐complexation‐assisted
deprotonation
undergoes
outer‐sphere
attack
silylating
reagent
give
propargylic
silanes,
latter
step
identified
enantiodetermining
step.