Angewandte Chemie,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 9, 2024
Abstract
Starting
from
N
‐acyl
sulfonimidamides,
mechanochemically
generated
rhodium
nitrenoids
undergo
intramolecular
N−O
couplings
to
provide
unprecedented
1,3,2,4‐oxathiadiazole
3‐oxides
in
good
excellent
yields.
The
cyclization
proceeds
efficiently
with
a
catalyst
loading
of
only
0.5
mol
%
the
presence
phenyliodine(III)
diacetate
(PIDA)
as
oxidant.
Neither
an
inert
atmosphere
nor
additional
heating
is
required
this
solvent‐free
procedure.
Under
heat
or
blue
light,
newly
formed
five‐membered
heterocycles
function
nitrene
precursors
reacting
sulfoxides
exemplified
by
imidation
dimethyl
sulfoxide.
Angewandte Chemie,
Год журнала:
2023,
Номер
136(2)
Опубликована: Ноя. 24, 2023
Abstract
Herein,
we
report
that
bulky
alkylphosphines
such
as
P
t
Bu
3
can
switch
the
roles
from
actor
to
spectator
ligands
promote
FeCl
2
‐catalyzed
N
‐amidation
reaction
of
arylamines
with
dioxazolones,
giving
hydrazides
in
high
efficiency
and
chemoselectivity.
Mechanistic
studies
indicated
phosphine
could
facilitate
decarboxylation
dioxazolones
on
Fe
center,
hydrogen
bonding
interactions
between
nitrenoid
intermediates
might
play
a
role
modulating
delicate
interplay
ligand,
arylamine,
acyl
nitrene
N,
favoring
N−N
coupling
over
N−P
coupling.
The
new
ligand‐promoted
protocols
offer
convenient
way
access
various
challenging
triazane
compounds
via
double
or
sequential
primary
arylamines.
Angewandte Chemie,
Год журнала:
2024,
Номер
136(14)
Опубликована: Фев. 17, 2024
Abstract
Nucleophilic
substitutions
are
fundamentally
important
transformations
in
synthetic
organic
chemistry.
Despite
the
substantial
advances
bimolecular
nucleophilic
(S
N
2)
at
saturated
carbon
centers,
analogous
S
2
reaction
amide
nitrogen
atom
remains
extremely
limited.
Here
we
report
an
substitution
method
with
amine
nucleophiles
for
nitrogen–nitrogen
(N−N)
bond
formation
that
leads
to
a
novel
strategy
toward
biologically
and
medicinally
hydrazide
derivatives.
We
found
use
of
sulfonate‐leaving
groups
played
pivotal
role
reaction.
This
new
N−N
coupling
allows
O
‐tosyl
hydroxamates
as
electrophiles
readily
available
amines,
including
acyclic
aliphatic
amines
‐heterocycles
nucleophiles.
The
features
mild
conditions,
broad
substrate
scope
(>80
examples),
excellent
functional
group
tolerability,
scalability.
is
applicable
late‐stage
modification
various
approved
drug
molecules,
thus
enabling
complex
scaffold
synthesis.
Research Square (Research Square),
Год журнала:
2024,
Номер
unknown
Опубликована: Апрель 16, 2024
Abstract
Photoelectrochemical
(PEC)
cell
is
an
ideal
platform
for
organic
transformation
because
of
its
green
benefits
and
minimal
energy
consumption.
As
emerging
methodology,
the
reaction
types
photoelecrocatalytic
synthesis
(PECOS)
are
limited
to
simple
oxidation
C–H
activation
at
current
stage.
Metal
catalysis
with
superiority
in
construction
C(sp2)–N
bonds
has
not
been
touched
yet
PECOS.
We
introduce
here
a
PEC
method
that
successfully
engages
Ni
mild
production
aniline
derivatives.
Experimental
computational
investigations
elucidate
addition
photoanode-generated
amine
radical
catalyst
avoids
sluggish
nucleophilic
attack,
enabling
proceed
ultra-low
potential
(–0.4
V
vs.
Ag/AgNO3)
preventing
overoxidation
products
conventional
electrochemical
synthesis.
This
synergistic
strategy
exhibits
good
functional
group
tolerance
wide
substrate
scope
on
both
aryl
halides
amines,
by
which
some
important
natural
pharmaceutical
chemicals
have
modified.
Angewandte Chemie,
Год журнала:
2024,
Номер
136(26)
Опубликована: Апрель 19, 2024
Abstract
A
highly
efficient
and
chemoselective
approach
for
the
divergent
assembling
of
unsymmetrical
hydrazines
through
an
unprecedented
intermolecular
desulfurdioxidative
N−N
coupling
is
developed.
This
metal
free
protocol
employs
readily
accessible
N
‐arylhydroxylamines
‐sulfinylanilines
to
provide
valuable
hydrazine
products
with
good
reaction
yields
excellent
functional
group
tolerance
under
simple
conditions.
Computational
studies
suggest
that
in
situ
generated
O
‐sulfenylated
arylhydroxylamine
intermediate
undergoes
a
retro‐[2π+2σ]
cycloaddition
via
stepwise
diradical
mechanism
form
bond
release
SO
2
.
Angewandte Chemie,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 9, 2024
Abstract
Starting
from
N
‐acyl
sulfonimidamides,
mechanochemically
generated
rhodium
nitrenoids
undergo
intramolecular
N−O
couplings
to
provide
unprecedented
1,3,2,4‐oxathiadiazole
3‐oxides
in
good
excellent
yields.
The
cyclization
proceeds
efficiently
with
a
catalyst
loading
of
only
0.5
mol
%
the
presence
phenyliodine(III)
diacetate
(PIDA)
as
oxidant.
Neither
an
inert
atmosphere
nor
additional
heating
is
required
this
solvent‐free
procedure.
Under
heat
or
blue
light,
newly
formed
five‐membered
heterocycles
function
nitrene
precursors
reacting
sulfoxides
exemplified
by
imidation
dimethyl
sulfoxide.
