Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(39)
Published: July 31, 2023
Abstract
Aryl
fluorides
are
important
structural
motifs
in
many
pharmaceuticals.
Although
the
Balz–Schiemann
reaction
provides
an
entry
to
aryl
from
aryldiazonium
tetrafluoroborates,
it
suffers
drawbacks
such
as
long
time,
high
temperature,
toxic
solvent,
gas
release,
and
low
functional
group
tolerance.
Here,
we
describe
a
general
method
for
synthesis
of
tetrafluoroborates
using
piezoelectric
material
redox
catalyst
under
ball
milling
conditions
presence
Selectfluor.
This
approach
effectively
addresses
aforementioned
limitations.
Furthermore,
can
be
recycled
multiple
times.
Mechanistic
investigations
indicate
that
this
fluorination
may
proceed
via
radical
pathway,
Selectfluor
plays
dual
role
both
source
fluorine
terminal
reductant.
Organic Process Research & Development,
Journal Year:
2024,
Volume and Issue:
28(5), P. 1903 - 1909
Published: Feb. 21, 2024
Solid-forming
reactions
are
notoriously
challenging
to
process
in
standard
flow
processes.
Even
though
the
formation
of
a
solid
product
within
reaction
can
facilitate
simple
purification,
homogeneous
often
utilized
enable
processing.
We
report
application
dynamic
spinning
disc
reactor
(SDR)
technology
as
strategy
handle
situ
while
handling
exothermic
chemistry.
The
system
is
exemplified
by
using
diazotization
and
azo
coupling
system.
Advantages
approach
include
use
water
sole
solvent,
mild
operating
conditions
(20
°C),
isolation
procedure
filtration
drying.
demonstrate
that
stable
operation
possible
for
120
min,
affording
55.9
g
Sudan
II.
Chemical Engineering & Technology,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 14, 2025
Abstract
3‐Amino‐1‐adamantanol
(3AA)
is
an
important
intermediate
of
vildagliptin.
In
this
work,
a
fully
continuous
flow
synthesis
3‐amino‐1‐adamantanol
has
been
proposed.
Selecting
amantadine
sulfate
(AS)
as
the
starting
material,
effects
process
parameters
were
systematically
investigated,
such
molar
ratio
reactants,
amount
sulfuric
acid
and
reaction
temperature.
The
kinetics
nitration
carried
out
in
both
batch
processes
to
explain
relationship
between
rate
constant.
Based
on
apparent
constants
thermodynamic
parameters,
3AA
combining
nitration,
hydrolysis
neutralization
realized.
Compared
with
method,
time
was
shortened
from
8
h
36
min,
side
reactions
significantly
inhibited,
yield
increased
87.8
%
95.2
by
strategy.
Organic Process Research & Development,
Journal Year:
2023,
Volume and Issue:
27(2), P. 322 - 330
Published: Jan. 16, 2023
A
proof-of-concept
study
for
the
synthesis
of
1,2-difluorobenzene
from
2-fluoroaniline
via
Balz–Schiemann
reaction
using
HF/pyridine
as
fluorinating
reagent
is
reported.
Key
to
success
a
fast
reaction,
clean
profile─and
thus
high
product
selectivity─was
photochemically
induced
fluorodediazoniation
in
situ-generated
diazonium
salt
performed
continuous
flow
mode.
high-power
365
nm
light-emitting
diode
provided
more
robust
and
efficient
irradiation
system
compared
medium-pressure
Hg
lamp
with
respect
performance
on
scale-out
runs
time,
allowing
generation
within
10
min
residence
time
selectivity
≥95%
at
full
conversion.
Current Opinion in Green and Sustainable Chemistry,
Journal Year:
2024,
Volume and Issue:
47, P. 100907 - 100907
Published: March 13, 2024
Reactive
intermediates
are
transient
high-energy
species
playing
a
pivotal
role
in
the
synthesis
of
organic
molecules.
Continuous
flow
processing
is
frequently
exploited
generating
plethora
reactive
situ
followed
by
their
rapid
transformation
to
target
Reactor
miniaturisation
along
with
high
heat
and
mass
transfer
rates
key
features
that
these
processes
provide
for
additional
benefits
such
as
safety
scalability.
This
short
review
highlights
recent
advances
field
chemistry
generation
use
photochemical
reactions,
low-temperature
sequences
well
related
transformations.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
62(2)
Published: Nov. 22, 2022
Abstract
Among
the
tools
available
to
chemists
for
drug
design
of
bioactive
compounds,
bioisosteric
replacement
atoms
or
groups
is
cornerstone
modern
strategies.
Despite
undeniable
interest
in
amino‐to‐hydroxyl
interchange,
enzymatic
deaminative
hydroxylation
remains
unmatched.
Herein,
we
report
a
user
friendly
and
safe
procedure
selectively
convert
aminoheterocycles
their
hydroxylated
analogues
by
means
simple
pyrylium
tetrafluoroborate
salt.
The
step
relies
on
Lossen‐type
rearrangement
under
mild
conditions
thus
avoiding
use
strong
hydroxide
bases.
In
addition
biorelevant
heterocycles,
electron‐deficient
anilines
was
also
demonstrated.
Finally,
mechanistic
experiments
allowed
identification
key
intermediates,
unveiling
rather
unusual
mechanism
this
formal
aromatic
substitution.
