Organic Chemistry Frontiers,
Journal Year:
2023,
Volume and Issue:
10(11), P. 2670 - 2679
Published: Jan. 1, 2023
A
general
mechanistic
map
involving
multiple
intermediates
and
pathways
has
been
proposed
systematically
studied
for
NHC-catalyzed
transformation
reactions
of
saturated
carboxylic
anhydrides.
The Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
89(5), P. 3133 - 3142
Published: Feb. 15, 2024
Organocatalytic
desymmetrization
reaction
is
a
powerful
tool
for
constructing
axial
chirality,
but
the
theoretical
study
on
origin
of
stereoselectivity
still
lags
behind
even
now.
In
this
work,
N-heterocyclic
carbene
(NHC)-catalyzed
biaryl
frameworks
synthesis
axially
chiral
aldehydes
has
been
selected
and
theoretically
investigated
by
using
density
functional
theory
(DFT).
The
fundamental
pathway
involves
several
steps,
i.e.,
desymmetrization,
formation
Breslow
oxidation,
esterification,
NHC
regeneration.
processes
have
identified
as
stereoselectivity-determining
rate-determining
steps.
Further
weak
interaction
analyses
proved
that
C–H···O
hydrogen
bond
C–H···π
interactions
are
responsible
stability
key
stereoselective
transition
states.
This
research
contributes
to
understanding
nature
NHC-catalyzed
reactions
compounds.
Catalysis Science & Technology,
Journal Year:
2023,
Volume and Issue:
13(18), P. 5259 - 5266
Published: Jan. 1, 2023
The
origin
of
regio-
and
stereoselectivities
NHC-catalyzed
enantioselective
radical
reactions
an
enal
a
pyridinium
salt
has
been
explored
via
theory
for
the
first
time.
Journal of Chemical Information and Modeling,
Journal Year:
2024,
Volume and Issue:
64(11), P. 4530 - 4541
Published: May 29, 2024
By
performing
molecular
dynamics
(MD),
quantum
mechanical/molecular
mechanical
(QM/MM)
calculations,
and
QM
cluster
the
origin
of
chemoselectivity
halohydrin
dehalogenase
(HHDH)-catalyzed
ring-opening
reactions
epoxide
with
nucleophilic
reagent
NO2−
has
been
explored.
Four
possible
chemoselective
pathways
were
considered,
computed
results
indicate
that
pathway
associated
attack
on
Cα
position
by
is
most
energetically
favorable
an
energy
barrier
12.9
kcal/mol,
which
close
to
14.1
kcal/mol
derived
from
experimental
kinetic
data.
A
hydrogen
bonding
network
formed
residues
Ser140,
Tyr153,
Arg157
can
strengthen
electrophilicity
active
site
substrate
affect
chemoselectivity.
To
predict
trends
transition
states,
multiple
analyses
including
distortion
analysis
electrophilic
Parr
function
(Pk+)
carried
out
or
without
enzyme
environment.
The
obtained
insights
should
be
valuable
for
rational
design
enzyme-catalyzed
biomimetic
organocatalytic
special
Journal of Chemical Information and Modeling,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 6, 2025
The
mechanisms
for
the
C(sp3)-H
activation
and
addition
reactions
between
acetonitrile
(or
acetone)
alkynes
have
been
investigated
with
M06-2X-D3/ma-def2-TZVP
method
basis
set.
SMD
(solvation
model
based
on
solute
electron
density)
was
applied
to
simulate
solvent
effect.
In
first
second
reactions,
2-phenylbut-3-yn-2-ol
reacted
acetone,
respectively.
First,
activations
of
acetone
could
be
achieved
by
PhCOO•
t-BuO•
radicals.
Then,
converted
into
final
products
P1
P2.
Gibbs
free
energy
surfaces
these
two
suggest
that
blue
lines
would
favorable
paths
lower
barriers,
terminal
C
atom
C≡C
bond
is
best
reactive
site.
Moreover,
analysis
IRI
(Interaction
Region
Indicator)
reveals
Z-
E-configuration
transformations.
While
in
third
fourth
methyl(2-(phenylethynyl)phenyl)sulfane
has
interactions
via
some
paths,
profiles
show
C10
atom,
rather
than
C11
priority,
are
favorable.
Furthermore,
action
mode
Na2HPO4
reduce
barrier
benefit
reaction.
vdW
(van
der
Waals)
play
an
important
role
choice
fifth
sixth)
reaction,
it
happened
1-(2-(methylthio)phenyl)-3-phenylprop-2-yn-1-one
acetontrile
yield
product
P5
P6).
computational
results
uncovered
line
path,
site
depends
interactions,
which
origin
selectivity.
addition,
investigation
byproducts
carried
out,
can
explain
reason
only
main
produced.
Both
those
agree
experimental
results.
localized
orbital
locator
(LOL)
isosurfaces,
Laplacian
order
(LBO),
density
critical
point
(ρBCP),
spin
isosurface
graphs,
graphs
used
analyze
structure
reveal
reaction
substances.
Nature Communications,
Journal Year:
2025,
Volume and Issue:
16(1)
Published: March 3, 2025
A
highly
enantioselective
electrophilic
selenylation/semipinacol
rearrangement
of
allenols
has
been
developed,
which
is
enabled
by
the
cooperative
catalysis
a
chiral
sulfide
and
an
achiral
sulfonic
acid.
The
designed
synthesized
catalyst
selenylating
reagent
play
crucial
role
in
enhancing
both
enantioselectivity
reactivity.
This
approach
exhibits
excellent
regio-,
chemo-,
enantioselectivity,
providing
access
to
diverse
enantioenriched
cyclopentanones
featuring
arylselenovinyl-substituted
quaternary
carbon
stereocenter.
Furthermore,
these
products
can
be
transformed
into
synthetically
valuable
alkyne,
vinyl
bromide,
aniline
derivatives.
Mechanistic
studies
reveal
that
combination
acid
not
only
facilitates
formation
catalytically
active
species,
but
also
governs
reaction.
Meanwhile,
density
functional
theory
calculations
disclose
four
hydrogen
bond
interactions
π‧‧‧π
interaction
are
responsible
for
observed
enantioselectivity.
Rearrangement
reactions
serve
as
steps
syntheses
biologically
provide
intellectual
conceptual
curiosities
within
broad
field
organic
chemistry.
Here,
authors
report
allenols,
catalysed
Lewis
base.
