Angewandte Chemie,
Journal Year:
2023,
Volume and Issue:
135(29)
Published: May 17, 2023
Abstract
Polyethyleneimines
find
many
applications
in
products
such
as
detergents,
adhesives,
cosmetics,
and
for
processes
tissue
culture,
gene
therapy,
CO
2
capture.
The
current
state‐of‐the‐art
technology
the
production
of
branched
polyethyleneimines
involves
aziridine
feedstock
which
is
a
highly
toxic,
volatile
mutagenic
chemical
raises
significant
concern
to
human
health
environment.
We
report
here
novel
method
synthesis
polyethyleneimine
derivative
from
ethylene
glycol
ethylenediamine
are
much
safer,
environmentally
benign,
commercially
available
potentially
renewable
feedstock.
polymerisation
reaction
catalysed
by
complex
an
earth‐abundant
metal,
manganese
liberates
H
O
only
by‐product.
Our
mechanistic
studies
using
combination
DFT
computation
experiment
suggest
that
proceeds
formation
subsequent
hydrogenation
imine
intermediates.
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
14(14), P. 10624 - 10634
Published: June 28, 2024
We
report
here
a
method
of
making
polyketones
from
the
coupling
diketones
and
diols
using
manganese
pincer
complex.
The
methodology
allows
us
to
access
various
(polyarylalkylketone)
containing
aryl,
alkyl,
ether
functionalities,
bridging
gap
between
two
classes
commercially
available
polyketones:
aliphatic
polyaryletherketones.
Using
this
methodology,
12
have
been
synthesized
characterized
analytical
techniques
understand
their
chemical,
physical,
morphological,
mechanical
properties.
Based
on
previous
reports
our
studies,
we
suggest
that
polymerization
occurs
via
hydrogen-borrowing
mechanism
involves
dehydrogenation
dialdehyde
followed
by
aldol
condensation
with
form
chalcone
derivatives
subsequent
hydrogenation
polyarylalkylketones.
Organometallics,
Journal Year:
2023,
Volume and Issue:
42(10), P. 1030 - 1036
Published: May 10, 2023
This
manuscript
describes
the
impact
of
metal
(ruthenium
versus
iron
manganese)
on
PNP
pincer
complex-catalyzed
dehydrogenative
coupling
formamides
with
alcohols
to
yield
carbamates.
Studies
are
conducted
compare
structure
and
reactivity
key
organometallic
intermediates
as
a
function
metal.
These
reveal
that
all
three
catalysts
undergo
fast
reaction
isocyanates
(the
initial
organic
products
formamide
dehydrogenation)
form
off-cycle
metallacyclic
species.
However,
structures
reactivities
these
vary
The
N-bound
isomer
metallacycle
is
formed
Fe
(literature)
Ru
(this
work),
while
both
O-bound
(kinetic)
(thermodynamic)
metallacycles
observed
Mn
work).
At
100
°C,
cycloadduct
reacts
rapidly
cyclohexanol
release
catalyst
along
corresponding
carbamate.
In
contrast,
show
dramatically
lower
toward
regeneration
under
analogous
conditions.
complexes
dehydrogenation
also
varies
metal,
≫
at
°C.
Overall,
complex
an
effective
for
conversion
variety
carbamates
150
°C
loadings
low
1
mol
%.
performance
substrate
scope
comparable
those
analogue.
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: July 24, 2024
Abstract
We
report
here
a
method
to
make
branched
and
partially
ethoxylated
polyethyleneimine
derivative
directly
from
ethanolamine.
The
polymerization
reaction
is
catalysed
by
pincer
complex
of
Earth-abundant
metal,
manganese,
produces
water
as
the
only
byproduct.
Industrial
processes
produce
polyethyleneimines
involve
transformation
ethanolamine
highly
toxic
chemical,
aziridine,
an
energy-intensive/waste-generating
process
followed
ring-opening
aziridine.
reported
bypasses
need
intermediate
presents
advantages
over
current
state-of-the-art.
propose
that
follows
hydrogen
borrowing
pathway
involves
(a)
dehydrogenation
form
2-aminoacetaldehyde,
(b)
dehydrative
coupling
2-aminoacetaldehyde
with
imine
derivative,
(c)
subsequent
hydrogenation
alkylated
amines.
Catalysis Science & Technology,
Journal Year:
2023,
Volume and Issue:
13(19), P. 5745 - 5756
Published: Jan. 1, 2023
We
report
manganese-catalyzed
CH
alkylation
of
indole/indolines
with
alcohols,
where
catalyst
control
provides
product
selectivity.
synthesise
several
life
science
molecules
(vibrindole
A,
turbomycin
B
alkaloid
and
antileukemic
anticancer
agents).
Chemistry - A European Journal,
Journal Year:
2023,
Volume and Issue:
30(1)
Published: Oct. 9, 2023
Abstract
In
the
present
work,
several
manganese(I)
complexes
of
chelating
heteroditopic
ligands
Mn1–3
,
featuring
ImNHC
(imidazol‐2‐ylidene)
connected
to
a
1,2,3‐triazole‐N
or
tzNHC
(1,2,3‐triazol‐5‐ylidene)
donors
via
methylene
spacer,
with
possible
modifications
at
triazole
backbone
have
been
synthesized
and
completely
characterized.
Notably,
CO
stretching
frequencies,
electrochemical
analysis,
frontier
orbital
analysis
certainly
suggest
that
ImNHC‐tzNHC
stronger
donation
capabilities
than
related
ImNHC‐Ntz
ligand
in
complexes.
Moreover,
these
well‐defined
phosphine‐free
Mn(I)−NHC
found
be
effective
non‐bifunctional
catalysts
for
α‐alkylation
nitriles
using
alcohols
importantly,
catalyst
Mn1
containing
weaker
triazole‐N
donor
displayed
higher
activity
compared
Mn2
/
Mn3
an
unsymmetrical
bis‐carbene
(ImNHC
tzNHC).
A
wide
range
aryl
were
coupled
diverse
(hetero)aromatic
as
well
aliphatic
get
corresponding
products
good
excellent
yields
(32
examples,
up
95
%
yield).
The
detailed
mechanistic
studies
including
deuterium
labelling
experiments
reveal
reaction
follows
Borrowing
Hydrogen
pathway.
