Interrupted Dance of Five Heteroatoms: Reinventing Ozonolysis to Make Geminal Alkoxyhydroperoxides from C═N Bonds
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(8), С. 5699 - 5714
Опубликована: Апрель 2, 2024
Four
heteroatoms
dance
in
the
cascade
of
four
pericyclic
reactions
initiated
by
ozonolysis
C═N
bonds.
Switching
from
imines
to
semicarbazones
introduces
fifth
heteroatom
that
slows
this
dance,
delays
reaching
thermodynamically
favorable
escape
path,
and
allows
efficient
interception
carbonyl
oxides
(Criegee
intermediates,
CIs)
an
external
nucleophile.
The
new
three-component
reaction
alcohols,
ozone,
oximes/semicarbazones
greatly
facilitates
synthetic
access
monoperoxyacetals
(alkoxyhydroperoxides).
Язык: Английский
Hydrosilylation or Dehydrogenative Silylation Pathways via the Au-Catalyzed Activation of Hydrosilanes
Journal of Organometallic Chemistry,
Год журнала:
2025,
Номер
unknown, С. 123546 - 123546
Опубликована: Янв. 1, 2025
Язык: Английский
Osmium catalysis in the reductive amination using carbon monoxide as a reducing agent
Molecular Catalysis,
Год журнала:
2020,
Номер
498, С. 111260 - 111260
Опубликована: Окт. 30, 2020
Язык: Английский
The Higher Propensity of Pd-SiHEt2+ over Pd-SiMe2Et+ to Transfer Silylium to Silyl Ether Intermediates Explains Divergent Products in Ketone Hydrosilylation Catalysis
Organometallics,
Год журнала:
2024,
Номер
43(11), С. 1256 - 1263
Опубликована: Май 31, 2024
The
catalytic
use
of
silylpalladium
cations
has
been
developed
for
the
hydrosilylation
ketones.
Product
outcome
was
heavily
influenced
by
hydrosilane
identity
with
tertiary
silanes
providing
silyl
ethers
and
secondary
silanes,
alkanes.
Stoichiometric
studies
suggest
a
key
differentiating
feature
is
ability
to
transfer
silylium
from
XantPhosPd-SiR3+
ether
intermediates
in
case
but
not
tertiary.
Formation
bimetallic
Pd
species
during
catalysis
points
behaving
as
source
both
electrophilic
ions
nucleophilic
Pd(0).
Язык: Английский
Au Nanoparticle-Catalyzed Double Hydrosilylation of Nitriles by Diethylsilane
Organic & Biomolecular Chemistry,
Год журнала:
2024,
Номер
22(26), С. 5346 - 5352
Опубликована: Янв. 1, 2024
We
present
the
first
example
of
Au-catalyzed
reduction
nitriles
into
primary
amines.
In
contrast
to
monohydrosilanes
which
are
completely
unreactive,
diethylsilane
(a
dihydrosilane)
is
capable
reducing
aryl
or
alkyl
amines
under
catalysis
by
Au
nanoparticles
supported
on
TiO
Язык: Английский
Substitution-Dependent Ring-Opening Hydrosilylation or Dehydrogenative Hydrosilylation of Cyclopropyl Aldehydes and Ketones Catalyzed by Au Nanoparticles
The Journal of Organic Chemistry,
Год журнала:
2022,
Номер
87(23), С. 15914 - 15924
Опубликована: Ноя. 17, 2022
The
reaction
between
hydrosilanes
and
aryl-substituted
cyclopropyl
aldehydes
or
ketones
catalyzed
by
Au
nanoparticles
supported
on
TiO2
provides
two
distinct
ring-opening
motifs
depending
the
substituents.
2-Aryl-substituted
carbonyl
compounds
form
linear
enol
ethers
via
formal
silyl
hydride
addition
carbon
atom
bearing
aryl
group.
Under
conditions,
hydrosilylation
adducts
undergo
hydrolytic
deprotection
to
acyclic
ketones.
For
2,2-arylalkyl-
2,2-diaryl-substituted
compounds,
a
dehydrogenative
pathway
is
solely
observed
yielding
chromatographically
stable
silyloxy-1,3-dienes.
In
presence
of
2,2,6,6-tetramethylpiperidine-1-oxyl
(TEMPO),
inhibited,
indicative
radical
pathway.
proposed
intermediate
α-cyclopropyl
silyloxy
radicals
radical-clock
benzyl
radicals,
which
may
either
be
captured
hydrosilane
H
(for
2-aryl-substituted
substrates)
eliminate
H2
silyloxy-1,3-dienes
in
case
bulkier
2,2-disubstituted
ones.
Язык: Английский
Transition Metal Promoted Synthesis of Isoindoline Derivatives
Опубликована: Апрель 15, 2022
Isoindoline
can
be
considered
as
the
"hydrogenated
sister"
of
isoindole
which
is
widespread
in
nature
heterocyclic
core
alkaloids
and
antibiotics.
This
chapter
devoted
to
analysis
methods
involving
use
transition
metal
catalysts
with
particular
regard
activity
specific
organometallic
species.
Transition-metal-catalysed
cyclisations
three
π-systems
have
been
deeply
investigated
valuable
synthetic
tool
for
generation
aromatic
rings.
Transition
metal-promoted
Diels-Alder
reactions
represent
a
very
convenient
methodology
synthesis
nonaromatic
nitrogen
heterocycles.
Several
metals
successfully
adopted
intramolecular
aza-Michael
addition
ortho-alkenyl
benzyl
amine
derivatives.
A
relevant
route
isoindolines
based
on
5-exo-dig
cyclization
through
C—C
bond
formation
achieved
by
a-arylation.
Язык: Английский
Reduction of Carbonyl Compounds by Diethylsilane Catalyzed by Titania-Supported Gold Nanoparticles
Synfacts,
Год журнала:
2020,
Номер
16(10), С. 1205 - 1205
Опубликована: Сен. 17, 2020
Key
words
gold
catalysis
-
nanoparticles
reduction
diethylsilane
carbonyl
compounds
catalyst
support
Язык: Английский
Deoxygenation of Epoxides with Hexamethyldigermane Catalyzed by Au Nanoparticles on TiO2
Asian Journal of Organic Chemistry,
Год журнала:
2021,
Номер
10(12), С. 3364 - 3369
Опубликована: Окт. 29, 2021
Abstract
Mono‐
and
disubstituted
epoxides
undergo
quantitative
deoxygenation
into
the
corresponding
alkenes
by
hexamethyldigermane
(Me
3
GeGeMe
)
in
presence
of
1
mol%
supported
Au
nanoparticles
on
TiO
2
,
with
digermane
being
transformed
digermoxane.
Tri‐
tetrasubstituted
react
either
poorly
or
remain
intact,
allowing
thus
selective
intermolecular
a
monosubstituted
epoxide
highly
substituted
one.
Stereoisotopic
studies
Hammett‐type
kinetics
indicate
dipolar
transition
state
process,
whose
degree
polarity
profile
depends
substituents.
For
alkyl‐substituted
is
almost
stereospecific
(retention
configuration),
while
for
aryl‐substituted
ones,
which
character
more
profound,
substantial
loss
stereospecificity
observed.
Язык: Английский