Organic Letters,
Год журнала:
2024,
Номер
26(3), С. 681 - 686
Опубликована: Янв. 17, 2024
This
study
presents
the
atroposelective
alkylation
of
2-arylindoles
catalyzed
by
a
substituted
cinchonium
salt
as
phase-transfer
catalyst.
Under
optimized
reaction
conditions,
various
substrates
are
employed
to
yield
products
with
high
enantioselectivity.
The
presence
an
ortho-nitro
group
at
aromatic
ring
is
essential
for
atroposelectivity,
because
it
facilitates
favorable
interactions
between
catalyst
and
substrate.
origin
enantioselectivity
reveals
π–π
both
enantiomers
unfavorable
steric
strains
undesired
enantiomers.
A
novel
P(═O)R2-directed
asymmetric
catalytic
olefination
has
been
developed,
enabling
efficient
access
to
carbon–nitrogen
axially
chiral
products
with
excellent
yields
(up
92%)
and
enantioselectivity
99%
enantiomeric
excess).
The
synergistic
coordination
of
phosphine
oxide
functionality
l-pGlu-OH
the
Pd
metal
center,
serving
as
an
directing
group
ligand,
was
key
success
this
C–H
functionalization
system.
reaction
demonstrated
a
broad
substrate
scope,
yielding
33
distinct
C–N
axial
products.
absolute
configuration
unambiguously
confirmed
via
X-ray
diffraction
analysis.
Additionally,
three
representative
applications
were
showcased,
involving
reduction
oxidation
produce
phosphines
related
derivatives.
plausible
cycle
mechanism
proposed,
supported
by
detailed
experimental
studies.
Aggregates
in
system
identified
aggregation-induced
polarization
experiments.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(47)
Опубликована: Окт. 11, 2023
An
intermolecular
enantioselective
N-alkylation
reaction
of
1H-indoles
has
been
developed
by
cooperative
rhodium
and
chiral
phosphoric
acid
catalyzed
N-H
bond
insertion
reaction.
N-Alkyl
indoles
with
newly
formed
stereocenter
adjacent
to
the
indole
nitrogen
atom
are
produced
in
good
yields
(up
95
%)
excellent
enantioselectivities
>99
%
ee).
Importantly,
both
α-aryl
α-alkyl
diazoacetates
tolerated,
which
is
extremely
rare
asymmetric
X-H
(X=N,
O,
S
et
al.)
C-H
reactions.
With
this
method,
only
0.1
mol
catalyst
2.5
required
complete
conversion
as
well
achieve
high
enantioselectivity.
Computational
studies
reveal
relay
acid,
origin
chemo
stereoselectivity.
Organic Letters,
Год журнала:
2024,
Номер
26(6), С. 1154 - 1159
Опубликована: Фев. 7, 2024
The
direct
functionalization
of
β-C(sp2)-H
bonds
in
enamides
has
garnered
increasing
attention
within
the
realm
organic
synthesis.
However,
these
remarkable
advancements
are
predominantly
dependent
on
transition
metals;
limited
success
been
achieved
via
organocatalytic
catalysis.
Herein,
we
report
a
CPA-catalyzed
cascade
intramolecular
cyclization
to
synthesize
chiral
dihydropyrimido[1,6-a]indoles
bearing
gem-difluoromethylene.
Moreover,
this
methodology
enables
synthesis
diverse
with
outstanding
enantioselectivities
moderate
high
yields.
Organic & Biomolecular Chemistry,
Год журнала:
2022,
Номер
21(3), С. 489 - 493
Опубликована: Дек. 8, 2022
Herein,
we
describe
a
challenging
organocatalytic
asymmetric
aza-
Friedel–Crafts
reaction
of
naphthols/phenols
with
cyclic-ketimines
attached
to
neutral
functional
group,
achieving
enantiomerically
enriched
chiral
aminonaphthols.
Organic Letters,
Год журнала:
2024,
Номер
26(3), С. 681 - 686
Опубликована: Янв. 17, 2024
This
study
presents
the
atroposelective
alkylation
of
2-arylindoles
catalyzed
by
a
substituted
cinchonium
salt
as
phase-transfer
catalyst.
Under
optimized
reaction
conditions,
various
substrates
are
employed
to
yield
products
with
high
enantioselectivity.
The
presence
an
ortho-nitro
group
at
aromatic
ring
is
essential
for
atroposelectivity,
because
it
facilitates
favorable
interactions
between
catalyst
and
substrate.
origin
enantioselectivity
reveals
π–π
both
enantiomers
unfavorable
steric
strains
undesired
enantiomers.
