Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(36)
Published: June 5, 2024
Pyrroles
and
indoles
bearing
N-allenyl
tethers
participate
in
a
variety
of
iridium-catalyzed
cycloisomerization
processes
initiated
by
C-H
activation
step,
to
deliver
diversity
synthetically
relevant
azaheterocyclic
products.
By
appropriate
selection
the
ancillary
ligand
substitution
pattern
allene,
reactions
can
diverge
from
simple
intramolecular
hydrocarbonations
tandem
involving
intriguing
mechanistic
issues.
Accordingly,
wide
range
heterocyclic
structures
ranging
dihydro-indolizines
pyridoindoles
tetrahydroindolizines,
as
well
cyclopropane-fused
tetrahydroindolizines
be
obtained.
Moreover,
using
chiral
ligands,
these
cascade
carried
out
an
enantioselective
manner.
DFT
studies
provide
insights
into
underlying
mechanisms
justify
observed
chemo-
regio-
stereoselectivities.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(19), P. 3347 - 3351
Published: May 10, 2023
The
Lewis-base-catalyzed
enantioselective
formal
[4
+
2]
annulation
reaction
of
o-acylamino-aryl
MBH
carbonates
and
electron-deficient
olefins
was
developed.
Tetrahydroquinolines
with
three
sequential
stereogenic
centers
containing
a
quaternary
stereocenter
were
obtained
in
high
yields
good
enantioselectivity.
Organic Letters,
Journal Year:
2022,
Volume and Issue:
24(10), P. 2008 - 2013
Published: March 10, 2022
We
report
an
unexpected
dearomative
periphery
modification
strategy
for
transforming
quinolinium
salts
into
structurally
crowded
pyrrolidine–tetrahydroquinoline
polycyclic
systems
with
complete
regio-
and
diastereoselectivity.
Importantly,
the
reaction
pathway
was
regulated
by
simply
tuning
substituents,
achieving
substituent-directed
divergent
synthesis.
The
notable
features
of
this
transformation
include
readily
available
starting
materials,
green
conditions,
a
simple
workup
procedure,
high
bond-
ring-forming
efficiency,
diverse
The Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
88(24), P. 17181 - 17196
Published: Nov. 28, 2023
A
convenient
synthetic
protocol
for
regioselective
and
diastereoselective
construction
of
complex
dispiro-indanone-fluorenone-oxindole
motifs
was
developed
by
the
base-promoted
annulation
reaction
bindone
MBH
carbonates
isatins
adjusting
conditions.
DABCO
promoted
in
DCM
at
room
temperature,
affording
dispiro[indene-2,4′-fluorene-1′,3″-indoline]
derivatives
good
yields
with
high
diastereoselectivity.
Triethylamine
two
molecular
1,3-indanediones
esters
ethanol
elevated
temperature
selectively
gave
dispiro[indene-2,4′-fluorene-3′,3″-indolines]
moderate
yields.
However,
triethylamine
excess
refluxing
ethanol,
Z-isomer
as
major
product
E-isomer
minor
product.
The Journal of Organic Chemistry,
Journal Year:
2020,
Volume and Issue:
86(2), P. 1779 - 1788
Published: Dec. 30, 2020
An
efficient
decarboxylative
[3
+
2]
annulation
reaction
of
ethynylethylene
carbonates
and
azlactones
has
been
developed
with
a
copper
salt
as
catalyst.
This
practical
methodology
gives
access
to
diverse
library
γ-butyrolactones
bearing
α,β-two
vicinal
quaternary
carbon
centers
in
good
high
yields
levels
diastereoselectivities
(up
98%
yield,
>95:5
dr).
Preliminary
trials
on
enantioselective
variant
chiral
PyBox
ligand
provided
products
up
71%
ee.
synthetic
method
features
mild
conditions,
broad
functional
group
tolerance,
large-scale
synthesis,
versatile
transformation.
A
plausible
catalytic
cycle
for
the
protocol
is
proposed
based
previous
related
studies
our
experimental
observations.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(7), P. 1472 - 1477
Published: Feb. 13, 2024
A
highly
efficient
enantioselective
[4
+
2]
cycloaddition
of
2-amino-β-nitrostyrenes
with
cyclic
N-sulfonyl
ketimines
has
been
developed.
This
reaction
utilizes
an
organocatalytic
approach,
employing
a
multiple-hydrogen-bonding
bifunctional
squaramide-based
catalyst.
The
process
allows
for
the
precise
synthesis
chiral
polycyclic
benzosultams,
showcasing
intricate
structures
that
incorporate
quaternary
centers.
Noteworthy
outcomes
this
method
include
high
yields
excellent
enantioselectivities
and
diastereoselectivities
(up
to
97%
yield,
96%
ee,
>20:1
dr).
A
cascade
reaction
of
α-aryl
vinyl
and
propargyl
sulfonium
salts
with
C-nucleophiles
afforded
functionalized
thioethers
via
Michael
addition
followed
by
[2,3]-sigmatropic
rearrangement.
The Journal of Organic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 6, 2025
We
report
a
domino
reaction
of
2-(2-acylvinyl)indoles
as
well
the
corresponding
pyrroles
with
styrylsulfonium
salts
under
mild
conditions,
affording
cyclopropamitosene
analogues
in
high
yields
and
complete
diastereoselectivity.
A
wide
range
(E)-β-hetaryl-α,β-unsaturated
ketones
were
successfully
employed
for
synthesis
potentially
bioactive
cyclopropa[3,4]pyrrolo[1,2-a]indoles
related
cyclopropa[a]pyrrolizines,
demonstrating
versatility
developed
method.
In
contrast,
(Z)-isomers
substrates
fail
to
give
derivatives
but
undergo
cyclopropanation
terminal
methyl
group.
Organic Letters,
Journal Year:
2020,
Volume and Issue:
22(21), P. 8451 - 8457
Published: Oct. 22, 2020
An
S-selective
arylation
of
pyridylsulfides
with
good
functional
group
tolerance
was
developed.
To
demonstrate
synthetic
utility,
the
resulting
pyridylsulfonium
salts
were
used
in
a
scalable
transition-metal-free
coupling
protocol,
yielding
functionalized
bipyridines
extensive
tolerance.
This
modular
methodology
permits
selective
introduction
groups
from
commercially
available
pyridyl
halides,
furnishing
symmetrical
and
unsymmetrical
2,2'-
2,3'-bipyridines.
Iterative
application
enabled
synthesis
terpyridine
three
different
pyridine
components.
The Journal of Organic Chemistry,
Journal Year:
2022,
Volume and Issue:
87(9), P. 5804 - 5816
Published: April 27, 2022
An
efficient
Cu-catalyzed
annulation
reaction
of
ketone
oxime
acetates
with
ortho-trifluoroacetyl
anilines
has
been
disclosed.
With
the
developed
protocol,
a
series
4-trifluoromethyl
quinolines
were
obtained
in
good
to
excellent
yields
(58-99%)
under
redox-neutral
conditions.
The
protocol
also
could
be
extended
ferrocene-based
for
construction
ferrocene-substituted
fluorine-containing
quinolines.
