Asian Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 9, 2024
Abstract
Phenyl‐4‐pyridyl‐2,5‐dipyrimidinylmethane
(
1
)
has
been
synthesized
in
five
steps
from
5‐methylpyrimidine.
The
structural
feature
of
is
the
symmetry
elements
with
respect
to
180°
rotation
aryl
group
along
central
C−C
bonds.
Due
this
feature,
compound
expected
good
crystallinity
despite
asymmetric
molecular
structure.
optical
resolution
was
achieved
by
high
performance
liquid
chromatography
using
chiral
stationary
phase
(chiral
HPLC).
circular
dichroism
(CD)
spectra
two
fractions
showed
opposite
signs.
As
expected,
X‐ray
crystallographic
analysis
successfully
performed
for
both
racemic
and
enantiomerically
pure
crystals
,
nitrogen
atoms
being
unambiguously
assigned
cases.
It
concluded
first‐eluted
fraction
HPLC
determined
be
S
configuration
CD
calculation
reproducing
experimental
spectrum
anomalous
diffraction
.
Nature Communications,
Journal Year:
2025,
Volume and Issue:
16(1)
Published: March 4, 2025
Nonlinear
effects
(NLEs)
serve
as
a
widespread
tool
in
the
study
of
asymmetric
catalytic
reactions.
However,
due
to
diversity
ligand-metal
coordination
modes,
information
obtained
solely
from
linear
relationship
between
ee
values
ligands
and
products
complex
systems
is
often
indirect.
Here,
we
report
precise
method
that
directly
connects
metal
complexes
products,
with
purpose
determining
active
species
occur
systems.
Through
an
in-depth
analysis
mechanism
our
previous
copper-catalyzed
esterification
reactions,
find
intrinsic
key
(LLCuI)
within
this
traditionally
non-linear
system.
This
holds
promise
powerful
for
exploration
catalysis
mechanisms,
heralding
new
avenues
understanding
application
processes.
Molecules,
Journal Year:
2024,
Volume and Issue:
29(6), P. 1307 - 1307
Published: March 15, 2024
New
arylamide-
and
arylthiourea-based
chiral
solvating
agents
(CSAs)
were
synthesized
starting
from
commercially
available
isomannide
isosorbide.
The
two
natural
isohexides
transformed
into
the
three
amino
derivatives,
having
isomannide,
isosorbide,
isoidide
stereochemistry,
then
groups
derivatized
with
3,5-dimethoxybenzoyl
chloride
or
3,5-bis(trifluoromethyl)phenyl
isothiocyanate
to
obtain
CSAs.
Bis-thiourea
derivative
containing
moiety
exo–exo
stereochemistry
was
remarkably
efficient
in
differentiation
of
NMR
signals
(NH
acetyl)
enantiomers
N-acetyl
(N-Ac)
acids
presence
1,4-diazabicyclo[2,2,2]octane
(DABCO).
Nonequivalences
ranges
0.104–0.343
ppm
0.042–0.107
for
NH
acetyl
groups,
respectively,
allowed
very
accurate
enantiomeric
excess
determination,
a
reliable
correlation
found
between
relative
positions
their
absolute
configuration.
Therefore,
complete
stereochemical
characterization
could
be
performed.
Dipolar
interactions
detected
ternary
mixture
CSA/N-Ac-valine/DABCO
led
identification
different
interaction
model
enantiomers,
involving
formation
one-to-one
substrate/CSA
complex
(S)-N-Ac-valine
one-to-two
(R)-N-Ac-valine,
as
suggested
by
complexation
stoichiometry.
Organic Chemistry Frontiers,
Journal Year:
2024,
Volume and Issue:
11(22), P. 6358 - 6366
Published: Jan. 1, 2024
This
work
reported
that
37
different
difficult-to-crystallize
guest
molecules
were
co-crystallized
with
the
host
macrocycle
F[3]A1-[P(O)Ph]3
at
room
temperature,
and
molecular
structures
of
guests
could
be
determined
by
SCXRD.
Analytical Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 19, 2025
The
quantification
of
molar
fractions
and
enantiomeric
excess
has
been
demonstrated
in
mixtures
d-
l-tryptophan
l-phenylalanine,
respectively,
avoiding
derivatization
the
analyte
with
additional
reagents
or
separation
steps.
technique
is
based
on
electrospray
ionization
(ESI),
which
allows
generation
anions
nonvolatile
compounds
such
as
amino
acids
large
biomolecules.
Electrons
are
photodetached
from
these
anions.
distribution
forward
backward
scattered
photoelectrons
analyzed,
leading
to
photoelectron
circular
dichroism
(PECD),
observable
interest.
concept
proven
by
blind
measurements
analyzing
unknown
composition.
(ee)
values
not
only
possible
for
signals
originating
molecular
anion
but
also
dimer
anion.
ESI-PECD
known
be
applicable
chemical
entities
several
thousand
Daltons.
Natural Product Reports,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 1, 2025
With
emerging
resistance
and
a
lag
in
the
development
of
new
molecules,
bioactive
natural
product
peptides
are
source
chemistries
to
drive
advances
medicine
biotechnology.
Analytical Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 11, 2025
High-throughput
mass
spectrometry
(HT-MS)
facilitates
rapid,
large-scale
data
acquisition,
providing
a
fast
and
efficient
solution
for
various
analytical
challenges.
However,
the
increasing
volume
of
generated
by
MS
requires
automation
easy-to-use
processing
tools.
Currently,
there
is
no
freely
available
software
that
compatible
with
most
instruments
species
authentication
or
classification.
Here,
we
introduce
RapidMass,
cutting-edge
platform
designed
to
automate
handling,
evaluation,
presentation,
management
HT-MS
identification.
Key
features
include
streamlined
workflow
spectra
from
(e.g.,
DI-MS,
ASAP-MS,
DART-MS),
three
specialized
algorithms
scoring
unknown
samples,
peak
annotation
review,
visualization
MS1
MS2
spectra,
an
expandable
personal
database
customized
management.
Performance
validation
conducted
on
nine
sets
covering
diverse
sample
compositions,
instrument
types,
suppliers,
resolutions,
acquisition
modes,
demonstrated
RapidMass's
excellent
performance,
times
12
20
s
per
accuracies
ranging
97%
100%
easily
confused
plants.
With
its
user-friendly
interface,
RapidMass
empowers
users
create
manage
personalized
databases,
presenting
significant
prospects
broad
applications
across
fields.
