European Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
26(35)
Published: July 27, 2023
Abstract
A
Friedel–Crafts
reaction
of
indolizines
with
2‐aryl‐3
H
‐indol‐3‐ones
catalyzed
by
B(C
6
F
5
)
3
is
described.
This
protocol
gives
access
to
indolizine
derivatives
that
are
valuable
building
blocks
in
synthetic
and
pharmaceutical
chemistry.
The
proceeds
under
mild
conditions,
affording
various
C2‐quaternary
indolin‐3‐ones
based
on
high
yields
regioselectivities.
Moreover,
the
transformations
target
products
were
realized
N‐methylation
trifluoromethane
sulfonation.
Chemical Science,
Journal Year:
2024,
Volume and Issue:
15(11), P. 3831 - 3871
Published: Jan. 1, 2024
In
the
vast
majority
of
top-selling
pharmaceutical
and
industrial
products,
phenolic
structural
motifs
are
highly
prevalent.
Non-functionalized
simple
phenols
serve
as
building
blocks
in
synthesis
value-added
chemicals.
It
is
worth
mentioning
that
lignin,
being
largest
renewable
biomass
source
aromatic
nature,
mainly
consists
units,
which
enable
production
structurally
diverse
phenols.
Given
their
remarkable
applicability
chemical
value
chain,
many
efforts
have
been
devoted
to
increasing
molecular
complexity
scaffold.
Among
key
techniques,
direct
functionalization
Csp
Organic & Biomolecular Chemistry,
Journal Year:
2023,
Volume and Issue:
21(21), P. 4393 - 4397
Published: Jan. 1, 2023
Herein,
we
describe
a
B(C
6
F
5
)
3
-catalyzed
redox-neutral
β-functionalization
of
tertiary
amines
with
cyclic-ketimines,
achieving
various
1,3-diamines
containing
the
indolin-3-one
moiety
via
borrowing
hydrogen
strategy.
Abstract
A
chiral
Brønsted
acid‐catalyzed
synthesis
of
axially
alkenes
was
developed
via
an
enantioselective
and
para
‐selective
Friedel–Crafts
reaction
between
phenols
1‐alkynylnaphth‐2‐ols.
This
methodology
features
efficient
hydroarylation
with
high
functional
group
tolerance,
complete
‐selectivity,
excellent
yields
(up
to
99%),
enantioselectivities
94%
ee)
in
the
presence
a
N
‐triflylphosphoramide
catalyst.
DFT
calculations
were
performed
investigate
‐selectivity
results
indicate
that
both
kinetics
thermodynamics
parameters
are
more
favorable
compared
ortho
‐selectivity.
2,2-Disubstituted
indolin-3-ones,
which
are
essential
components
in
many
manufactured
chemicals,
dyes,
and
naturally
occurring
bioactive
alkaloids,
have
emerged
as
exciting
synthetic
targets.
Much
attention
has
been
paid
to
accessing
these
units,
particularly
an
asymmetric
fashion,
during
the
last
decade.
In
this
review
article,
we
discuss
current
state
of
available
methods
with
existing
mechanistic
pathways
for
chiral
indolin-3-one
derivatives
under
various
catalytic
systems.
This
overall
presentation
protocols
access
2,2-disubstituted
or
fused
indolin-3-ones
aza-quaternary
centre
is
categorized
based
on
reaction
modes
2-substituted-3H-indole-3-one
other
similar
protocols.
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.
ACS Catalysis,
Journal Year:
2023,
Volume and Issue:
13(14), P. 9495 - 9501
Published: July 3, 2023
The
conventional
acid-catalyzed
aza-Friedel–Crafts
reaction
of
phenols
with
imines
typically
proceeds
in
an
ortho-selective
manner.
A
chiral
bis(imidazolidine)
pyridine
(PyBidine)-Ni(OAc)2
catalyst
switches
the
regioselectivity
to
para-selectivity.
By
replacement
benzyl
substituent
parent
PyBidine
a
bulky
Ph2CHCH2
substituent,
"bulky
PyBidine"-Ni(OAc)2
enabled
highly
para-selective
reactions
(up
99:1
para/ortho
selectivity).
With
assistance
Sr(OAc)2
additive,
wide
range
3,5-dialkoxyphenols
sulfonylaldimines
gave
para-substituted
products
up
93%
ee.
DFT
calculations
suggest
that
cooperative
activation
from
nickel
phenoxide
formation
(HOMO
activation)
and
hydrogen
bonding
sulfonylaldimine
(LUMO
is
key
for
switching
regioselectivity.
Chemistry - An Asian Journal,
Journal Year:
2023,
Volume and Issue:
18(18)
Published: Aug. 2, 2023
Abstract
A
facile
enantioselective
alkynylation
of
cyclic
ketimines
attached
to
a
neutral
functional
group
utilizing
the
dual
Cu(I)‐CPA
catalysis
is
described.
The
strategy
2‐aryl‐3
H
‐indol‐3‐one
directly
chiral
propargylic
amines
containing
indolin‐3‐one
moiety
in
good
yields
and
enantioselectivities.
Moreover,
gram‐scale
synthesis
propargylamines
based
C2‐quaternary
indolin‐3‐ones
was
performed.
synthetic
applications
were
confirmed
by
transformations
products
with
no
decrease
yield
enantioselectivity.
Asian Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
12(8)
Published: July 6, 2023
Abstract
Indol‐3‐ones
are
readily
available
reaction
substrates,
but
their
utility
in
asymmetric
reactions
is
underdeveloped.
Herein,
we
describe
the
organocatalytic
aza‐Friedel‐Crafts‐type
of
indol‐3‐ones
with
1‐
and
2‐naphthols.
By
using
spirocyclic
chiral
phosphoric
acids
quinine‐incorporated
squaramides
as
organocatalysts,
two
classes
structurally
distinct
compounds,
namely
2‐(hydroxylnaphthyl)‐indolin‐3‐ones
tetrahydrofuroindoles,
formed
respectively.
These
quaternary
centre‐containing
indoline
derivatives
may
find
use
synthesis
biologically
active
molecules.
European Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
27(31)
Published: June 7, 2024
Abstract
Here,
we
have
successfully
achieved
the
addition
of
difluoroacetate
radicals
to
2‐aryl‐3
H
‐indol‐3‐ones,
enabling
various
difluoroalkylations
C2‐tetrasubstituted
2‐aryl
indolin‐3‐ones
in
a
highly
efficient
and
economical
manner.
It
is
worth
mentioning
that
these
difluoroalkylation
compounds
can
be
easily
transformed
into
derivatives
under
mild
reaction
conditions.
Control
experiments
suggest
involvement
ethyl
radical
species
reaction.
