Chemistry - A European Journal,
Journal Year:
2023,
Volume and Issue:
29(71)
Published: Sept. 28, 2023
Metal-free
catalytic
C-H
functionalization
is
highly
desired
for
the
construction
of
C-C
bonds.
We
herein
report
a
chemoselective
consecutive
[2+3]-cyclative
simultaneous
formation
two
bonds
with
polycyclic
phenols
catalyzed
by
commercially
available
and
low-cost
B(C6
F5
)3
.
This
system
tolerates
wide
range
substrate
scope,
providing
series
2,6,7,8-tetrahydroacenaphthylen-3-ol-type
compounds
efficiently.
Several
derivatizations
products
have
also
been
conducted
to
show
potential
application
this
method
in
synthesis
compounds.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(35)
Published: May 10, 2024
A
copper-catalyzed
C4-selective
addition
of
silicon
nucleophiles
released
from
an
Si-B
reagent
to
prochiral
pyridinium
triflates
is
reported.
The
dearomatization
proceeds
with
excellent
enantioselectivity
using
Cu(CH
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(49), P. 8797 - 8802
Published: Dec. 1, 2023
A
straightforward
methodology
for
the
enantioselective
synthesis
of
1,2-dihydrophthalazines
via
dearomatization
phthalazines
by
anion-binding
catalysis
has
been
developed.
The
process
involves
Mannich-type
addition
silyl
ketene
acetals
to
in
situ
generated
N-acylphthalazinium
chlorides
using
a
tert-leucine
derived
thiourea
as
H-bond
donor
catalyst.
Ensuing
selective
and
high-yielding
transformations
provide
appealing
dihydro-
tetrahydro-phthalazines,
phthalazones,
piperazic
acid
homologues,
en
route
biologically
relevant
molecules.
Chemistry - A European Journal,
Journal Year:
2024,
Volume and Issue:
30(39)
Published: May 13, 2024
The
in
situ
generation
of
active
photoredox
organic
catalysts
upon
anion-binding
co-catalysis
by
making
use
the
ionic
nature
common
photosensitizers
is
reported.
Hence,
merge
and
photocatalysis
permitted
modulation
photocatalytic
activity
simple
acridinium
halide
salts,
building
an
effective
-
ion
pair
complex
able
to
promote
a
variety
visible
light
driven
transformations,
such
as
anti-Markovnikov
addition
olefins,
Diels-Alder
desilylative
C-C
bond
forming
reactions.
Anion-binding
studies,
together
with
steady-state
time-resolved
spectroscopy
analysis,
supported
postulated
formation
between
thiourea
hydrogen-bond
donor
organocatalyst
salt,
which
proved
essential
for
unlocking
photosensitizer.
Synthesis,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Aug. 8, 2024
Abstract
In
recent
years,
the
significance
of
spirocyclic
motifs
in
drug
discovery
has
increased,
owing
to
their
unique
ability
engage
biological
targets.
We
present
first
example
PIFA-mediated
dearomative
spirocyclization
phenol-tethered
pyrazoles,
highlighting
intramolecular
trapping
by
pyrazole
moiety.
This
method
efficiently
affords
a
variety
spirocyclohexadienone-pyrazolo[3,4-b]piperidinones
with
yields
up
82%.
Mechanistic
studies
reveal
that
dearomatization
process
involves
cationic
intermediate.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(51), P. 9164 - 9169
Published: Dec. 14, 2023
We
describe
here
an
organocatalytic
asymmetric
cascade
formal
[3
+
3]
cycloaddition
of
benzothiazoles
with
2-nitroallylic
acetates
and
nitroenynes.
This
dearomative
methodology
provided
a
facile
efficient
strategy
for
the
construction
broad
range
valuable
benzothiazolopyridines
bearing
two
adjacent
stereogenic
centers
in
moderate
to
good
yields
excellent
stereocontrol.
A
computational
analysis
of
possible
routes
cooperative
catalysis
involving
hydrogen
bond
donating
thiourea
and
halogen
organocatalysts
has
been
carried
out
at
the
M06-2X/SDD
level
theory
using
solvation
model
based
on
density
(SMD).
For
systems
2-iodoimidazolium
or
iodonium
salt
derivatives,
previously
suggested
route
including
sequential
electrophilic
activation
a
reaction
electrophile
via
XB-activated
HB
donor
was
ruled
out.
European Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
27(11)
Published: Dec. 28, 2023
Abstract
Thioureas
catalyze
the
reaction
of
phosphonites
with
in
situ‐
generated
isoquinolinium
salts
to
give
C
and
P
‐stereogenic
α‐aminophosphinates
high
enantioselectivity
(up
96
%)
yield
95
%).
Low
diastereoselectivity
was
obtained
this
is
rationalized
context
a
mechanistic
proposal
involving
anion‐binding
catalysis
P−C
bond
formation
step
followed
by
uncatalyzed
Arbuzov
collapse.
The
scope
reaction,
including
g‐scale
example,
demonstrated.
The Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
89(14), P. 10258 - 10271
Published: July 11, 2024
Dearomatization
is
a
fundamental
chemical
reaction
that
affords
complex
three-dimensional
heterocyclic
frameworks.
We
disclose
the
first
organocatalytic
dearomatization
of
5-aminopyrazoles,
which
yields
range
structurally
diversified
C4-hydroxylated
pyrazolines
with
≤95%
in
<1.5
h
at
room
temperature.
This
catalytic
process
achieved
using
