Mechanism and stereoselectivity in metal and enzyme catalyzed carbene insertion into X–H and C(sp2)–H bonds
Chemical Society Reviews,
Год журнала:
2024,
Номер
53(22), С. 11004 - 11044
Опубликована: Янв. 1, 2024
This
review
provides
a
mechanistic
overview
of
asymmetric
Fe,
Cu,
Pd,
Rh,
Au
and
heme-based
enzymes
catalyzed
carbene
insertion
reactions
to
construct
C–X
(X
=
O,
N,
S,
etc.
)
C–C
bonds,
focusing
on
the
stereochemical
models.
Язык: Английский
A combined experimental and computational study reveals a crossover between conventional cross-coupling and carbene insertion pathways in a Pd catalyzed C(sp2)–H insertion
Chemical Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
Computational
(DFT
and
DLPNO-CCSD(T))
calculations
along
with
experimental
tools
(deuterium
labelling,
kinetic
studies
using
VTNA,
ESI-HRMS
UV)
are
used
to
probe
the
mechanism
of
a
Pd(ii)-catalyzed
enantioselective
carbene
insertion
into
C(sp2)-H
indole.
Using
deuterium
labelling
studies,
we
demonstrate
intermediacy
metal-hydride
species,
which
contrasts
mechanistic
routes
for
other
transition
metals
(Rh,
Fe,
Au,
Cu,
etc.).
Our
VTNA
study
reveals
order
be
one
in
both
diazo
indole,
microkinetic
modelling
aligns
well
computationally
predicted
mechanism.
The
is
further
supported
by
detection
most
stable
intermediate
catalytic
cycle
ESI-HRMS.
An
investigation
origin
stereoselectivity
DLPNO-CCSD(T)
presents
new
paradigm,
wherein
stereocontrol
arises
during
formation
Pd
itself
as
opposed
proton
transfer
steps
found
all
metal
catalysts.
Язык: Английский
Solvent-Mediated Rate Deceleration of Diels–Alder Reactions for Enhanced Selectivity: Quantum Mechanical Insights
Chemistry,
Год журнала:
2024,
Номер
6(5), С. 1312 - 1325
Опубликована: Окт. 21, 2024
Solvents
can
have
a
tremendous
influence
on
the
rate
and
selectivity
of
chemical
reactions,
but
their
effects
are
not
always
well
accounted
for.
In
present
work,
density
functional
theory
computations
used
to
investigate
solvent
Diels–Alder
reactions
9-methylanthracene
with
(5-oxo-2H-furan-2-yl)
acetate
different
anhydrides
considering
overall
reaction
rates
as
between
possible
isomeric
products.
Crucially,
we
find
that
higher
in
non-polar
toluene,
whereas
is
enhanced
polar
acetone.
case
acetate,
difference
barriers
by
2.4
kJ/mol
acetone
compared
gas
phase,
halving
yield
side
product.
Similar
results
found
for
chloro-maleic
anhydride
cyano-maleic
anhydride,
highlighting
generality
trends
observed.
After
presenting
energetics,
detailed
discussion
reactivity
given
using
electrostatic
potentials,
frontier
orbitals,
indices
Fukui
functions.
summary,
this
study
highlights
importance
influencing
illustrates
possibility
studying
its
computationally.
Язык: Английский