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.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
147(3), С. 2776 - 2785
Опубликована: Янв. 8, 2025
The
asymmetric
Tsuji-Trost
reaction
has
been
extensively
studied
due
to
its
importance
in
establishing
stereogenic
centers,
often
adjacent
an
E-olefin
moiety
organic
molecules.
generally
preferential
formation
of
chiral
products
is
believed
result
from
the
thermodynamically
more
stable
syn-π-allylpalladium
intermediate.
rapid
associative
π-σ-π
isomerization
makes
it
challenging
synthesize
Z-olefin
via
transient
anti-π-allylpalladium
Herein,
we
report
a
strategy
for
regulating
by
tuning
steric
bulkiness
ligands,
allylic
leaving
groups,
and
counteranions.
utilization
Pd
catalyst
derived
phosphoramidite
ligands
interrupts
isomerization,
enabling
highly
efficient
Z-retentive
toward
array
α-amino
acid
derivatives
bearing
motif
high
yields
(up
95%)
excellent
stereoselectivity
99%
ee
>19:1
Z/E)
with
low
loading
(0.1
mol
%).
mechanistic
insights
design
reported
this
work
pave
way
rational
developments
Tsuji-Trost-type
reactions.
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.
ACS Catalysis,
Год журнала:
2023,
Номер
13(4), С. 2555 - 2564
Опубликована: Фев. 6, 2023
A
stereodivergent
synthesis
of
chiral
β-lactams
with
contiguous
tertiary/quaternary/tertiary
stereocenters
has
been
achieved
by
a
Cu/Ir-catalyzed
three-component
interrupted
Kinugasa
allylic
alkylation
reaction.
The
two
catalysts
independently
exert
high
local
stereocontrol,
providing
access
to
four
the
eight
possible
stereoisomers
in
yields
>99%
ee.
features
this
strategy
are
asymmetric
simultaneous
dual
metal-catalyzed
cascade
reactions
stereoselective
coupling
highly
transient
organometallic
intermediates.
Journal of the American Chemical Society,
Год журнала:
2022,
Номер
144(23), С. 10162 - 10167
Опубликована: Июнь 3, 2022
The
first
asymmetric
total
synthesis
of
bioactive
diterpenoid
hypoestin
A
with
an
unprecedented
[5-8-5-3]
tetracyclic
skeleton
is
accomplished
in
15
steps
from
commercially
available
(R)-limonene.
Furthermore,
the
second
syntheses
sesterterpenoids
albolic
acid
and
ceroplastol
II
21
are
also
reported.
synthetically
challenging
highly
functionalized
[X-8-5]
(X
=
5
or
7)
tricarbocyclic
ring
systems
found
A,
acid,
II,
schindilactone
as
well
other
natural
products,
efficiently
directly
constructed
via
a
unique
intramolecular
Pauson-Khand
reaction
allene-yne.
This
work
represents
reported
use
to
access
eight-membered-ring
product
synthesis.
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(5), С. 2884 - 2900
Опубликована: Янв. 25, 2023
The
involvement
of
planar
carbocation
intermediates
is
generally
considered
undesirable
in
asymmetric
catalysis
due
to
the
difficulty
gaining
facial
control
and
their
intrinsic
stability
issues.
Recently,
suitably
designed
chiral
catalyst(s)
have
enabled
a
guided
approach
nucleophiles
one
prochiral
faces
carbocations
affording
high
enantiocontrol.
Herein,
we
present
vital
mechanistic
insights
from
our
comprehensive
density
functional
theory
(B3LYP-D3)
study
on
Ir-phosphoramidite-catalyzed
reductive
deoxygenation
racemic
tertiary
α-substituted
allenylic
alcohols.
catalytic
transformation
relies
synergistic
action
phosphoramidite-modified
Ir
catalyst
Bi(OTf)3,
first
leading
formation
an
Ir-π-allenyl
intermediate
through
turn-over-determining
SN1
ionization,
followed
by
face-selective
hydride
transfer
Hantzsch
ester
analogue
yield
enantioenriched
product.
Bi(OTf)3
was
found
promote
significant
number
ionic
interactions
as
well
noncovalent
(NCIs)
with
substrates
(allenylic
alcohol
ester),
thus
providing
access
lower
energy
route
compared
pathways
devoid
Bi(OTf)3.
In
nucleophilic
addition,
induction
depend
efficacy
such
key
NCIs.
curious
case
reversal
enantioselectivity,
when
α-substituent
allenyl
changed
methyl
cyclopropyl,
identified
originate
change
mechanism
enantioconvergent
pathway
(α-methyl)
dynamic
kinetic
(α-cyclopropyl).
These
molecular
could
lead
newer
strategies
tame
enantioselective
reactions
using
suitable
combinations
catalysts
additives.
ACS Catalysis,
Год журнала:
2024,
Номер
14(20), С. 15743 - 15750
Опубликована: Окт. 9, 2024
Medium-sized
rings
are
important
structural
units
in
organic
molecules
of
significant
interest.
However,
their
efficient
synthesis,
especially
a
highly
enantioselective
manner,
has
been
formidable
challenge.
Herein,
we
report
an
synthesis
medium-sized
aza-rings
by
Z-retentive
asymmetric
allylic
substitution-enabled
intermolecular
cascade
cyclization
via
iridium/cinchona
dual
catalysis.
The
reaction
was
performed
under
mild
conditions
and
with
good
functional
group
tolerance.
Various
nine-
to
eleven-membered
can
be
afforded
moderate
high
yields
(up
98%)
enantioselectivities
93%
ee).
utilization
both
Z-linear
dipole
precursor
binary
catalyst
is
critical
for
the
desired
reactivity.
Organic Letters,
Год журнала:
2023,
Номер
25(25), С. 4621 - 4626
Опубликована: Июнь 15, 2023
We
present
here
an
iridium-catalyzed
diastereo-
and
enantioselective
[4
+
1]
cycloaddition
reaction
of
hydroxyallyl
anilines
with
sulfoxonium
ylides
under
mild
conditions,
leading
to
3-vinyl
indolines
in
moderate
good
yields
excellent
enantioselectivities.
Control
experiments
disclosed
a
plausible
mechanism.
