SSRN Electronic Journal,
Год журнала:
2022,
Номер
unknown
Опубликована: Янв. 1, 2022
Reaction
of
thiopyrano[4,3-
b
]indole-3(5
H
)-thiones
and
dimethyl
acetylenedicarboxylate
proceed
via
two
competing
cascade
pathways.
Both
mechanisms
have
been
investigated
in
detail
by
DFT
PCM/B3LYP/6-311++G(d,p)
quantum
chemical
calculations.
Initially,
the
reactions
occur
an
alkyne–thiocarbonyl
metathesis
or
(3+2)
cycloaddition
mechanisms.
At
next
stages,
parallel
rearrangements
both
cases
proceed,
including
thiopyrane
rings
opening
thiophene
closure.
Cycloaddition
processes
intermediate
thioketones
a
second
equivalent
DMAD
leads
to
resulting
]indole
derivatives
bearing
thienyl
substituent.
The Chemical Record,
Год журнала:
2023,
Номер
23(7)
Опубликована: Апрель 12, 2023
Abstract
This
account
summarizes
our
recent
efforts
in
the
enantioselective
organocatalytic
synthesis
of
chiral
halogenated
compounds.
The
α‐halogenation
aldehydes,
decarboxylative
chlorination
β‐keto
acids,
and
C−C
bond
formation
at
trifluoromethylated
prochiral
carbon
to
yield
corresponding
organohalides
with
chlorinated,
fluorinated,
or
stereogenic
centers
are
discussed.
We
applied
common
organocatalysts,
such
as
Jørgensen‐Hayashi
catalyst
cinchona
alkaloid‐derivatived
catalyst,
developed
novel
amine
catalysts
for
these
reactions.
also
discusses
stereospecific
derivatizations
resulting
compounds
via
nucleophilic
substitution.
Thus,
we
synthesized
many
that
have
not
been
reported,
even
racemates.
The Journal of Organic Chemistry,
Год журнала:
2022,
Номер
87(18), С. 11968 - 11978
Опубликована: Сен. 5, 2022
A
C2-symmetrical
bis-thiourea
chiral
solvating
agent
(CSA),
TFTDA,
for
NMR
spectroscopy
has
been
obtained
by
reacting
(1R,2R)-1,2-bis(2-hydroxyphenyl)ethylenediamine
and
3,5-bis(trifluoromethyl)phenyl
isothiocyanate.
TFTDA
shows
remarkable
propensity
to
enantiodiscriminate
N-trifluoroacetyl
(N-TFA)
N-acetyl
(N-Ac)
derivatives
of
amino
acids
with
free
carboxyl
functions,
the
co-presence
1,4-diazabicyclo[2.2.2]octane
(DABCO)
as
third
achiral
additive,
which
is
needed
substrate
solubilization.
enhanced
enantiodiscriminating
efficiency
in
comparison
corresponding
monomeric
counterpart,
TFTMA,
pointing
out
cooperativity
between
its
two
symmetrical
entities.
wide
range
acid
have
efficiently
enantiodiscriminated
CDCl3,
high
enantioresolution
quotients,
guarantee
quality
applications
devoted
quantification
enantiomers.
High
maintained
also
diluted
5
mM
conditions
or
presence
sub-stoichiometric
amounts
CSA
(0.3
equiv).
The
role
phenolic
hydroxyls
DABCO-mediated
interaction
mechanism
enantiomeric
substrates
pointed
means
diffusion-ordered
(DOSY)
rotating
frame
Overhauser
effect
(ROESY)
experiments.
conformational
model
both
diastereomeric
solvates
formed
enantiomers
leucine
conceived
on
basis
ROE
data
order
give
a
discrimination
rationale.
Bulletin of the Korean Chemical Society,
Год журнала:
2022,
Номер
43(7), С. 896 - 911
Опубликована: Июнь 2, 2022
Abstract
The
asymmetric
phase‐transfer
catalysis
(PTC)
is
a
flourishing
field
of
contemporary
synthetic
organic
chemistry,
and
this
prominent
methodology
has
been
tremendously
successful
in
enantioselective
halogenations.
Both
electrophilic
nucleophilic
reaction
manifolds
were
enabled
through
the
exploitation
highly
ordered
ion
pairing
and/or
hydrogen‐bonding
interactions
around
carefully
designed
chiral
catalyst
with
an
insoluble
halogenating
reagent
as
well
suitable
substrate.
Fluorination
most
fruitful,
encouraging
results
have
also
documented
heavier
halogens.
This
review
surveys
examples
various
halogenations
via
PTC
from
its
beginning
to
prosperity
over
past
decade.
Advanced Synthesis & Catalysis,
Год журнала:
2021,
Номер
364(4), С. 811 - 830
Опубликована: Дек. 16, 2021
Abstract
An
asymmetric
Sulfa‐Michael/Michael
domino
reaction
of
(
E
)‐4‐mercapto‐2‐butenoates
with
difluoromethyl‐eneoxindoles
catalyzed
by
a
quinidine‐derived
ammonium
salts
as
phase
transfer
catalyst
has
been
disclosed.
Under
mild
conditions,
broad
range
CF
2
H‐containing
spiro[indoline‐3,3′‐thiophene]s,
bearing
three
adjacent
chiral
centers
including
two
vicinal
spiro
quaternary
stereocenters,
catalysed
only
5
mol%
PTC
were
obtained
in
yields
75–98%,
excellent
diastereoselectivities
(>20:1,
almost
all
cases)
and
enantioselectivities
19–98%
short
times
(almost
less
than
20
minutes).
magnified
image
Synthesis,
Год журнала:
2022,
Номер
54(23), С. 5233 - 5244
Опубликована: Июль 3, 2022
Abstract
A
method
for
radical
cyclization
of
N-methacryloyl-2-arylbenzoimidazoles
with
nitriles,
ketones,
and
tert-butyl
nitrite
(TBN)
the
preparation
benzimidazo[2,1-a]isoquinolin-6(5H)-ones
advantage
mild
reaction
conditions,
excellent
functional
group
compatibility,
broad
substrate
scope
is
reported.
The
present
strategy
has
favorable
characteristics:
(1)
use
cheap
metal
catalysis;
(2)
N-radical-initiated
N-methacryloyl-2-arylbenzoimidazoles;
(3)
rare
example
C(sp3)–H
functionalization
in
this
cyclization.
Journal of Sulfur Chemistry,
Год журнала:
2022,
Номер
44(2), С. 248 - 259
Опубликована: Окт. 28, 2022
Reaction
of
thiopyrano[4,3-b]indole-3(5H)-thiones
and
dimethyl
acetylenedicarboxylate
(DMAD)
proceeds
via
two
competing
cascade
pathways.
Initially,
both
the
pathways
begin
from
thiocarbonyl
sulfur
acetylene
carbon
atoms
interaction.
Then
parallel
processes
take
place:
an
alkyne–thiocarbonyl
metathesis
a
(3
+
2)
cycloaddition.
In
next
stages,
in
cases,
thiophene
ring
formation
thiopyran
opening
proceed.
Finally,
(4
cycloaddition
reactions
intermediate
thioketones
second
equivalent
DMAD
leads
to
resulting
thiopyrano[4,3-b]indole
derivatives
bearing
thienyl
substituent.
The
kinetic
thermodynamic
characteristics
were
compared
on
basis
DFT
ab
initio
6-311++G(d,p)
quantum
chemical
calculations.
Beilstein Journal of Organic Chemistry,
Год журнала:
2024,
Номер
20, С. 1462 - 1467
Опубликована: Июль 1, 2024
Herein,
we
report
the
first
environmentally
friendly
systematic
fluoroalkoxylation
reactions
in
bicyclic
systems.
New
oxyfluorination
products
were
obtained
with
excellent
yields
(up
to
98%)
via
Wagner–Meerwein
rearrangement
using
benzonorbornadiene
and
chiral
natural
compound
(+)-camphene
as
alkenes,
selectfluor
an
electrophilic
fluorine
source,
water
various
alcohols
nucleophile
sources.
The
structure
of
oxy-
alkoxyfluorine
compounds
was
determined
by
NMR
QTOF-MS
analyses.
SSRN Electronic Journal,
Год журнала:
2022,
Номер
unknown
Опубликована: Янв. 1, 2022
Reaction
of
thiopyrano[4,3-
b
]indole-3(5
H
)-thiones
and
dimethyl
acetylenedicarboxylate
proceed
via
two
competing
cascade
pathways.
Both
mechanisms
have
been
investigated
in
detail
by
DFT
PCM/B3LYP/6-311++G(d,p)
quantum
chemical
calculations.
Initially,
the
reactions
occur
an
alkyne–thiocarbonyl
metathesis
or
(3+2)
cycloaddition
mechanisms.
At
next
stages,
parallel
rearrangements
both
cases
proceed,
including
thiopyrane
rings
opening
thiophene
closure.
Cycloaddition
processes
intermediate
thioketones
a
second
equivalent
DMAD
leads
to
resulting
]indole
derivatives
bearing
thienyl
substituent.
