Angewandte Chemie,
Год журнала:
2024,
Номер
136(47)
Опубликована: Авг. 7, 2024
Abstract
The
first
enantioselective
Friedel‐Crafts
(FC)
allenylation
reaction
for
the
creation
of
central
chirality
is
developed
under
cooperative
Ir(I)/(phosphoramidite,olefin)
and
Lewis
acid
catalysis.
This
enantioconvergent
utilizes
racemic
allenylic
alcohol
as
electrophile
shows
compatibility
with
a
variety
electron‐rich
arenes
heteroarenes.
resulting
highly
enantioenriched
(up
to
>99.5
:
0.5
e.r.)
1,1‐disubstituted
methanes,
bearing
benzylic
carbon
stereocenter,
are
obtained
complete
regiocontrol
–
both
on
(hetero)arenes
well
fragment.
protocol
allows
formal
introduction
4‐carbon
alkyl
chain
into
(hetero)arenes,
along
stereocenter.
Judicious
synthetic
elaborations
not
only
lead
FC
alkylation
products
less
but
also
substituted
in
ortho
‐
even
meta
‐selective
fashion.
An
intramolecular
version
this
shown
proceed
promising
enantioselectivity
same
catalytic
conditions.
Mechanistic
studies
revealed
involvement
dynamic
kinetic
asymmetric
transformation
(DyKAT)
alcohols
reaction.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(31), С. 21837 - 21846
Опубликована: Июль 26, 2024
The
interest
in
the
discovery
and
development
of
skeletal
editing
processes
that
selectively
insert,
exchange,
or
delete
an
atom
organic
molecules
has
significantly
increased
over
last
few
years.
However,
this
class
proceed
through
creation
a
chiral
center
with
high
asymmetric
induction
have
been
largely
unexplored.
Herein,
we
report
enantioselective
single-carbon
insertion
aryl-
alkyl-substituted
alkenes
mediated
by
catalytically
generated
Rh-carbynoid
phosphate
nucleophiles
produce
enantioenriched
allylic
phosphates
(enantiomeric
ratio
(e.r.)
=
89.5:10.5-99.5:0.5).
key
to
process
was
diastereo-
cyclopropanation
alkene
formation
transient
cyclopropyl-I
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(37), С. 25878 - 25887
Опубликована: Сен. 3, 2024
The
highly
efficient
synthesis
of
chiral
indolines
fused
with
an
azabicyclo[2.2.1]heptanone
moiety
is
achieved
by
asymmetric
dearomatization
reaction
indoles
cyclobutanones.
A
new
imidodiphosphorimidate
(IDPi)
catalyst
synthesized
and
exhibits
extraordinary
activity
in
promoting
a
cascade
Friedel-Crafts/semipinacol
rearrangement.
Target
molecules
are
prepared
good
yields
(up
to
95%)
excellent
enantioselectivity
98%
ee)
operational
convenience.
Combined
experimental
computational
studies
provide
detailed
mechanistic
insights
into
the
energy
landscape
origin
stereochemical
induction
reaction.
We
report
a
chiral
phosphoric
acid-catalyzed
hydrolytic
parallel
kinetic
resolution
(HPKR)
of
racemic
epoxides
and
activated
alcohols.
Using
an
acyloxy-assisted
activation
strategy,
this
method
enables
the
highly
stereocontrolled
hydrolysis
under
mild
conditions.
A
wide
range
aryl-substituted
secondary
alcohols
were
effectively
transformed,
providing
corresponding
with
combined
yields
up
to
99%
enantiomeric
ratios
exceeding
99:1.
An
asymmetric
oxidation
of
N,N-dialkyl
sulfenamides
is
exhibited
by
using
anionic
stereogenic-at-cobalt(III)
complexes
as
catalysts.
This
protocol
provides
an
alternative
approach
to
access
a
diverse
set
chiral
tertiary
sulfinamides
with
high
enantioselectivities
(24
examples,
up
94:6
e.r.).
Additionally,
control
experiments
suggest
that
this
could
be
accomplished
through
cationic
S(IV)
intermediate.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 9, 2025
Phosphorus(V)
stereocenters
that
are
fully
substituted
by
heteroatoms
play
important
roles
in
bioactive
molecules
and
organocatalysts.
Existing
methods
to
achieve
such
motifs
rely
almost
entirely
on
resolution
or
diastereocontrol,
prefunctionalized
substrates
usually
required
generate
specific
P(V)
stereocenters.
In
contrast,
related
catalytic
rare,
no
generally
applicable
method
is
described.
Here,
we
report
a
modular
strategy
access
broad
variety
of
stereogenic-at-phosphorus
skeletons,
including
ProTide
analogs,
alkoxylphosphoramidates,
phosphates,
phosphorothioates,
phosphonamidates,
through
designed
enantioselective
continuous
substitutions
simple
precursors.
The
nucleophilic
substitution
sequence
readily
determined
the
stereoconfiguration
products.
Concise
synthesis
analogs
drug
demonstrated
practical
value
protocol.
Experimental
computational
studies
unveiled
unique
π-π
stacking
effect
chalcogen
bonding
interaction
between
catalyst
substrate
as
origin
stereoselectivity.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 27, 2025
We
present
a
stereoretentive
nucleophilic
substitution
of
homoallylic
tertiary
alcohols
via
the
formation
nonclassical
cyclopropyl
carbinyl
(CPC)
carbocation
intermediate.
This
strategy
enables
creation
highly
congested
centers
with
preserved
stereocontrol,
addressing
typical
challenges
instability
and
reactivity
in
SN1
mechanisms.
The
stabilization
CPC
intermediate
is
crucial
for
achieving
precise
regio-
stereoselectivity,
significantly
enhancing
utility
SN1-type
mechanisms
complex
molecule
synthesis.
