Organic Letters,
Journal Year:
2017,
Volume and Issue:
19(22), P. 6140 - 6143
Published: Nov. 2, 2017
An
N-bromosuccinimide-catalyzed
intermolecular
annulation
of
acetyl
indoles
with
alkynes
was
developed,
allowing
for
regioselective
formation
valuable
carbazoles
through
direct
C-H
bond
functionalization.
The
readily
available
catalyst,
wide
substrate
scope,
gram
scale
synthesis,
and
mild
conditions
make
this
method
practical.
Mechanistic
investigations
indicate
that
the
bromination
indole
takes
place
to
generate
a
bromide
intermediate,
followed
by
coupling
an
alkyne
intramolecular
cycloaromatization
furnish
carbazole
products.
Organic Letters,
Journal Year:
2017,
Volume and Issue:
19(17), P. 4576 - 4579
Published: Aug. 17, 2017
Highly
efficient
methods
for
the
synthesis
of
2-arylbenzothiazoles
and
2-arylnaphtho[2,1-d]thiazoles
have
been
developed.
Readily
available
aromatic
amines,
benzaldehydes,
elemental
sulfur
were
directly
assembled
through
oxidative
annulation
C–H
functionalization
under
transition-metal-free
conditions,
where
DMSO
or
oxygen
served
as
oxidant.
NH4I
KI
catalyst
was
found
to
be
effective
promote
transformations
give
products
in
good
excellent
yields
with
wide
functional
group
tolerance.
Chemical Science,
Journal Year:
2021,
Volume and Issue:
12(29), P. 10092 - 10096
Published: Jan. 1, 2021
Radical
spirocyclization
via
dearomatization
has
emerged
as
an
attractive
strategy
for
the
rapid
synthesis
of
structurally
diverse
spiro
molecules.
We
report
use
electrochemistry
to
perform
oxidative
biaryls
leading
tri-
and
difluoromethylated
spiro[5.5]trienones
in
a
user
friendly
undivided
cell
set-up
constant
current
mode.
The
catalyst-
chemical
oxidant-free
procedure
features
ample
scope,
employs
electricity
green
sole
oxidant.
Organic Chemistry Frontiers,
Journal Year:
2021,
Volume and Issue:
8(11), P. 2710 - 2771
Published: Jan. 1, 2021
This
review
presents
a
critical
and
authoritative
analysis
of
several
exciting
benzannulation
approaches
developed
in
the
past
decade
for
construction
carbazoles,
indolocarbazoles,
benzocarbazoles,
carbolines.
The Journal of Organic Chemistry,
Journal Year:
2017,
Volume and Issue:
82(6), P. 2935 - 2942
Published: Feb. 21, 2017
An
efficient
one-pot
two-step
indole-to-carbazole
strategy
has
been
developed.
This
transition
metal-free
methodology
uses
oxygen
as
the
sole
oxidant
and
starts
from
cheap
readily
available
indoles,
ketones,
alkenes.
The
present
protocol
efficiently
enables
assembly
of
a
diverse
array
substituted
carbazole
products
with
good
regioselectivity
broad
tolerance
functional
groups.
Organic Letters,
Journal Year:
2017,
Volume and Issue:
19(19), P. 5074 - 5077
Published: Sept. 18, 2017
Gold(III)-catalyzed
cycloisomerization
of
α-bis(indol-3-yl)methyl
alkynols
selectively
affords
1-(indol-3-yl)carbazoles,
in
a
transformation
that
takes
place
through
selective
1,2-alkyl
vs
1,2-vinyl
migration
step
the
vinyl-gold
intermediate
generated
from
initial
5-endo-spirocyclization.
The
reaction
proceeds
well
with
either
tertiary
or
secondary
starting
as
wide
variety
alkyne
substituents.
key
role
other
indol-3-yl
substituent
for
unexpected
selectivity
1,2
rearrangement
has
also
been
supported
by
DFT
calculations
reveal
low
barrier,
two-step
mechanism
alkyl
path
where
second
indole
significantly
stabilizes
carbocationic
intermediate.
Organic Letters,
Journal Year:
2017,
Volume and Issue:
19(14), P. 3743 - 3746
Published: June 29, 2017
An
NH4I-based
reductive
system
has
been
explored
to
promote
the
oxime
N–O
bond
cleavage
and
thereby
enable
a
modular
synthesis
of
broad
range
pharmacologically
significant
fluorinated
pyridines.
Compared
with
traditional
condensation
methods
for
pyridine
assembly,
this
protocol
was
found
be
highly
regio-
chemoselective
presented
functional
group
tolerance.
Organic Letters,
Journal Year:
2019,
Volume and Issue:
21(9), P. 3372 - 3376
Published: April 23, 2019
A
new,
one-pot
domino
benzannulation
reaction
between
indole-3-ynones
and
various
nitromethane
derivatives
has
been
explored
for
a
general
entry
to
diversely
functionalized
carbazole
frameworks
(28
examples).
The
scope
of
this
new
extended
variants
like
2-chloroindole-3-ynones
eventuate
in
chemo-differentiated
1,2,3,4-tetrasubstituted
carbazoles
with
retention
the
nitro
group.
efficacy
strategy
demonstrated
through
concise
total
synthesis
natural
products,
viz.
carbazomycin
A,
calothrixin
B,
staurosporinone
(K252c).
Organic Letters,
Journal Year:
2021,
Volume and Issue:
23(11), P. 4406 - 4410
Published: May 21, 2021
A
novel
Rh(III)-catalyzed
C–H
activation/annulation
cascade
of
indole-enaminones
with
diazo
compounds
was
reported
to
construct
diversely
functionalized
carbazole
frameworks.
The
most
notable
characteristic
is
that
this
transformation
could
smoothly
furnish
a
[5
+
1]
cyclization
product
good
excellent
yields
(up
95%),
accompanied
by
the
thorough
removal
acetyl
and
N,N-dimethyl
groups
two
substrates
from
target
products,
rather
than
normally
expected
[4
2]
products.
