Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(3), P. 681 - 686
Published: Jan. 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.
Organic Letters,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 11, 2025
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,
Journal Year:
2023,
Volume and Issue:
62(47)
Published: Oct. 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,
Journal Year:
2024,
Volume and Issue:
26(6), P. 1154 - 1159
Published: Feb. 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,
Journal Year:
2022,
Volume and Issue:
21(3), P. 489 - 493
Published: Dec. 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,
Journal Year:
2024,
Volume and Issue:
26(3), P. 681 - 686
Published: Jan. 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.
