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
Calcium‐Catalyzed Multicomponent Reactions in Organic Synthesis
Asian Journal of Organic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 19, 2025
Abstract
Calcium
catalysis
has
garnered
significant
attention
from
synthetic
organic
chemists
as
a
sustainable
alternative
to
Lewis
acidic
transition
metals,
rare‐earth
and
strong
Brønsted
acids.
This
alkaline
earth
metal,
abundant
in
nature,
environmentally
benign,
moisture‐tolerant,
biodegradable,
low
toxicity,
offers
distinct
advantages.
catalysts
exhibit
exceptional
proficiency
activating
diverse
functional
groups,
particularly
π‐activated
species
such
ketones,
alcohols,
enamines,
aldehydes,
alkenes,
alkynes,
allenes,
thereby
enabling
nucleophilic
additions
tandem
chemical
transformations.
These
characteristics
resonate
with
the
core
tenets
of
green
chemistry,
enhancing
atom
step
economy
while
minimizing
waste
generation.
review
presents
thorough
in‐depth
analysis
calcium‐catalyzed
multi‐component
reactions
(MCRs),
underscoring
their
transformative
role
advancing
synthesis.
Furthermore,
it
explores
untapped
potential
calcium
broadening
horizons
MCRs,
fostering
innovative
eco‐friendly
methodologies
for
applications
pharmaceuticals
materials
science.
Key
challenges
future
prospects
within
this
evolving
domain
are
also
critically
examined.
Язык: Английский
Divergent Reactions of α-Diazo 1,3-Dicarbonyl Compounds with Allylic Carbonates Involving Ketene versus Carbene Intermediates Enabled by Cooperative Rh(II)/Pd(0) Dual Catalysis
Organic Letters,
Год журнала:
2024,
Номер
26(37), С. 7920 - 7925
Опубликована: Сен. 9, 2024
A
cooperative
Rh(II)/Pd(0)
dual-catalysis
strategy
that
enabled
divergent
reactions
of
α-diazo
1,3-dicarbonyl
compounds
with
allylic
carbonates
involving
ketene
versus
carbene
intermediates
is
described.
The
efficient
synthesis
α-quaternary
allylated
β-keto-esters
was
accomplished
by
the
alkylation
compounds.
Alternatively,
an
unprecedented
(1+4)
annulation
2-(hydroxymethyl)allyl
via
dual
catalysis
also
successfully
developed,
affording
a
wide
variety
tetrahydrofurans
in
good
to
high
yields.
Язык: Английский
Three‐component allylic alkylation reaction of α‐diazo ketones with water and allyl carbonates for construction of homoallylic alcohols
Advanced Synthesis & Catalysis,
Год журнала:
2024,
Номер
366(17), С. 3616 - 3623
Опубликована: Июнь 20, 2024
Abstract
A
three‐component
allylic
alkylation
reaction
of
α‐diazo
ketones,
water
and
allyl
carbonate
under
the
cooperative
catalysis
Rh
2
(OAc)
4
,
Pd
(dba)
3
Brønsted
acid
was
disclosed.
This
method
provides
an
expeditious
access
to
α‐keto
homoallylic
alcohols
in
good
high
yields.
Controlled
experiments
support
that
transformations
proceed
through
cross‐interception
two
active
intermediates
Pd‐allyl
species
enol
derived
from
oxonium
ylides.
Moreover,
synthetic
generated
products
enable
creation
motifs
enriched
with
dense
functional
groups,
underscoring
their
potential
as
valuable
building
blocks.
Язык: Английский
Cesium and Phenoxide Interaction Enabled by Rh Overrides the Innate Solvent-Mediated Chemoselectivity
ACS Catalysis,
Год журнала:
2024,
Номер
14(16), С. 12351 - 12358
Опубликована: Авг. 5, 2024
DLPNO-CCSD(T)
calculations
are
carried
out
to
understand
the
distinctive
chemoselectivity
in
a
Rh(II)-catalyzed
carbene
insertion
into
C(sp2)–H
bond
unprotected
phenols
without
preinstalled
directing
groups.
As
per
conventional
rules
of
solvation
and
separated
ion
pair
polar
aprotic
solvents
like
acetonitrile,
reaction
should
have
resulted
an
O–H
insertion.
However,
our
reveal
transition
state
model
that
helps
overriding
innate
acetonitrile.
It
involves
explicit
participation
added
Cs2CO3
base,
where
interaction
between
phenoxide
oxygen
Cs
cation,
but
not
as
metal-bound
phenoxide,
is
crucial
for
controlling
chemoselectivity.
Our
study
will
be
helpful
developing
further
reactions
with
broad
catalyst,
substrate,
solvent
scope.
Язык: Английский