Chinese Journal of Chemistry,
Год журнала:
2024,
Номер
42(18), С. 2133 - 2139
Опубликована: Май 7, 2024
Comprehensive
Summary
Heteronuclear
metal
complexes
have
played
an
increasingly
important
role
in
both
small
molecules
activation
and
catalytic
transformation
due
to
the
potential
metal‐metal
synergies.
In
this
work,
we
reported
that
well‐defined
Mg‐Ni‐Mg
complex
[(
L
Mg)
2
Ni(C
H
4
)
]
{
=
[(DippNCMe)
CH]
−
,
Dipp
2,6‐
i
Pr
C
6
3
}
was
capable
of
catalyzing
conversion
a
diverse
array
terminal
alkenes
hydrosilylated
products
anti
‐Markovnikov
fashion
using
PhSiH
as
silicon
source.
The
stoichiometric
reaction
heterometallic
with
one
equivalent
obtained
silyl‐nickel‐monohydride
NiH(C
)(SiHPhEt)]
featuring
Ni‐Si‐H‐Mg
interaction.
Moreover,
treatment
three
equivalents
provided
silyl‐nickel‐trihydride
NiH
(SiHPhEt)]
hydride‐bridged
at
fragment.
Further
reactions
resultant
silyl‐nickel
alkenes,
e.g.,
ethylene
styrene,
yielded
corresponding
alkene‐coordinated
],
(C
)]
(CH
CHPh)],
respectively,
elimination
PhEtSiH
.
Based
on
control
experiments,
were
considered
active
intermediates
hydrosilylation
reaction.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(21)
Опубликована: Март 12, 2024
Abstract
The
nuanced
role
of
spin
effects
remains
a
critical
gap
in
designing
proficient
open‐shell
catalysts.
This
study
elucidates
an
iron‐catalyzed
allylic
C(
sp
3
)−H
silylation/alkyne
hydrosilylation
reaction,
which
the
state
iron
catalyst
dictates
reaction
kinetics
and
pathway.
Specifically,
crossover
led
to
alkyne
hydrosilylation,
whereas
conservation
resulted
novel
silylation
reaction.
chemoselectivity,
governed
by
spin‐crossover
efficiency,
reveals
unexpected
dimension
first
realm
transition‐metal‐catalyzed
situ
bonds,
had
been
previously
inhibited
heightened
reactivity
alkenes
reactions.
Furthermore,
this
can
either
accelerate
or
hinder
at
different
stages
within
single
catalytic
phenomenon
scarcely
documented.
Moreover,
we
identify
substrate‐assisted
C−H
activation
mechanism,
departure
from
known
ligand‐assisted
processes,
offering
fresh
perspective
on
strategies.
Chemical Science,
Год журнала:
2022,
Номер
13(26), С. 7873 - 7879
Опубликована: Янв. 1, 2022
Although
research
on
iron-catalysed
reactions
has
recently
achieved
significant
progress,
the
activity
and
selectivity
of
iron
catalysts
are
generally
inferior
to
those
noble-metal
catalysts.
The
development
new
reactions,
especially
in
which
exhibit
superior
or
other
catalysts,
is
key
promote
catalysis.
Herein,
we
report
first
protocol
for
hydroalumination
internal
alkynes.
Specifically,
presence
bearing
2,9-diaryl-1,10-phenanthroline
ligands,
alkynes
were
stereo-
regioselectively
hydroaluminated
with
commercially
available
reagent
diisobutylaluminum
hydride.
Compared
metal-catalysed
alkyne
reported
literature,
following
advantages:
unusual
amino-group-directed
regioselectivity,
a
wide
substrate
scope,
good
functional
group
tolerance,
high
selectivity,
mild
reaction
conditions.
alkenylaluminum
products
prepared
this
way
could
undergo
diverse
array
transformations,
used
synthesis
bioactive
compounds.
current
study
expands
scope
catalysis,
provides
efficient
access
alkenylaluminum,
discloses
origin
superiority
thus
may
inspire
further
studies
related
fields.
Acta Chimica Sinica,
Год журнала:
2023,
Номер
81(7), С. 777 - 777
Опубликована: Янв. 1, 2023
Throughout
the
history
of
transition-metal
catalysis,
almost
every
breakthrough
is
closely
related
to
development
ligands.Therefore,
catalysis
roughly
parallels
ligand
lies
in
heart
transition
metal
catalysis.Since
beginning
homogeneous
metals
have
been
accompanied
by
phosphine
ligands
(Wilkinson's
catalyst).Till
now,
are
one
most
widely
used
types.There
several
key
factors
for
popularity
ligands,
among
which
backbone
plays
a
decisive
role
supporting
their
stability,
activity
and
selectivity.Many
privileged
contain
five-or
six-membered
rings
core
structures,
possibly
due
ready-availability,
low
ring
strain,
high
stability.Seven-and
above
membered
cyclic
structures
flexible
frameworks,
many
stable
conformations,
difficult
synthesize,
making
them
unsuitable
as
backbones.The
cyclobutane
structure
has
relatively
strong
but
its
conformation
can
be
flipped,
it
inappropriate
skeleton,
too.As
smallest
all-carbon
ring,
three
carbon
atoms
cyclopropane
located
same
plane.Because
unique
electronic
rigidity
cyclopropane,
changing
substituent
on
any
will
affect
substituents
other
two
carbons.And
simple
synthesize
modify,
promising
skeleton.However,
surprising
that
with
rarely
studied
so
far,
applications
need
further
explored,
too.Based
types
this
perspective
systematically
summarizes
reported
phosphine-containing
(including
monophosphines,
diphosphines,
phosphine-heteroatoms
triphosphines)
backbone,
catalysis.We
hope
draw
researchers'
attention
cyclopropane-based
thus
promote
catalysis.
Abstract
As
the
monomers
of
proteins,
amino
acids
are
critical
in
chemistry
and
biology,
playing
important
roles
multiple
fields
such
as
synthetic
chemistry,
medicinal
materials
chemistry.
Unlike
proteinogenic
acids,
unnatural
can
be
difficult
to
obtain
from
living
organisms
generally
synthesized
chemically.
Recently,
a
method
involving
asymmetric
N−H
bond
carbene
insertion
reaction
with
α‐diazoacetates
precursor
has
shown
high
enantioselectivity
good
functional
group
tolerance,
allowing
for
facile
synthesis
natural
introduction
new
concepts
catalysis.
The
Wittig
reaction,
which
is
one
of
the
most
effective
methods
for
synthesizing
alkenes
from
carbonyl
compounds,
generally
gives
thermodynamically
stable
Chemical Science,
Год журнала:
2024,
Номер
15(19), С. 7130 - 7135
Опубликована: Янв. 1, 2024
Chiral
phosphorus-containing
compounds
find
applications
across
various
fields,
including
asymmetric
catalysis,
medicinal
chemistry,
and
materials
science.
ACS Central Science,
Год журнала:
2024,
Номер
11(1), С. 36 - 45
Опубликована: Авг. 16, 2024
Multicomponent
reactions
(MCRs),
highly
sought-after
methods
to
produce
atom-,
step-,
and
energy-economic
organic
syntheses,
have
been
developed
extensively.
However,
catalytic
asymmetric
MCRs,
especially
those
involving
radical
species,
remain
largely
unexplored
owing
the
difficulty
in
stereoselectively
regulating
extraordinarily
high
reactivity
of
open-shell
species.
Herein,
we
report
a
conceptually
novel
three-component
cascade
reaction
readily
accessible
glycine
esters,
α-bromo
carbonyl
compounds
2-vinylcyclopropyl
ketones
via
synergistic
photoredox/Brønsted
acid
catalysis,
which
three
sequential
C–C
(σ/π/σ)
bond-forming
events
occurred
through
addition/ring-opening/radical–radical
coupling
protocol,
affording
an
array
valuable
enantioenriched
unnatural
α-amino
derivatives
bearing
two
contiguous
stereogenic
centers
alkene
moiety
moderate
good
yield
with
diastereoselectivity,
excellent
enantioselectivity
E-dominated
geometry
under
mild
conditions.
The
relay
process,
unique
proton-coupled
electron
transfer
(PCET)-promoted
radical–radical
coupling,
is
supported
by
mechanistic
investigations
quantum
mechanics
calculations
should
garner
broad
interest
further
inspire
development
multicomponent
reactions.
Chinese Journal of Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Июнь 3, 2025
Comprehensive
Summary
The
chiral
cyclopropane
framework
is
a
crucial
structural
motif
in
bioactive
molecules
such
as
pharmaceuticals
and
natural
products.
Asymmetric
cyclopropanation
of
alkenes
via
transition
metal‐catalyzed
carbene
transfer
represents
one
the
most
direct
approaches
for
synthesizing
cyclopropanes.
While
significant
progress
has
been
made
asymmetric
α‐C‐substituted
carbenes,
highly
enantioselective
α‐silyl
which
possess
greater
transformation
potential,
remains
largely
unexplored.
In
this
study,
we
report
Cu(I)/chiral
bisoxazoline
catalytic
system
that
enables
cyclopropanation/Cope
rearrangement
reactions
between
α‐silyl‐α‐alkenyl
carbenes
(generated
from
ring
opening
1‐silyl
cyclopropene)
alkenes.
This
methodology
provides
access
to
series
cyclopropylsilanes
containing
stereogenic
quaternary
carbon
centers
well
allylic
silane
moieties
cycloheptadienylsilanes,
thereby
expanding
diversity
organosilicon
compounds.
Theoretical
calculations
reveal
rate‐determining
step
involves
cyclopropene,
where
silyl
group
not
only
dictates
regioselectivity
but
also
significantly
influences
stereoselectivity
reaction
through
its
steric
rigid
properties.
ACS Catalysis,
Год журнала:
2022,
Номер
12(21), С. 13143 - 13148
Опубликована: Окт. 13, 2022
We
have
developed
a
method
for
highly
enantioselective
N–H
bond
insertion
reactions
of
α-alkyl-α-diazoacetates
and
various
carbamates
cooperatively
catalyzed
by
TpCu,
where
Tp
=
(hydrotris(4,5-bromopyrazolyl)borate),
chiral
spiro
phosphoric
acid.
These
provide
straightforward
access
to
unnatural
optically
active
N-carbonate
α-alkyl-α-amino
esters,
which
are
widely
used
in
artificial
peptide
synthesis.
This
mild
uses
readily
available
starting
materials
features
broad
substrate
scope,
good
functional
group
tolerance,
high
yields
(58–88%),
enantioselectivities
(90–96%
ee).
The
combination
the
neutral
copper
catalyst
TpCu
acid
ensures
success
reaction
inhibiting
β-H
migration
carbene
intermediate
promoting
proton
transfer
an
enolate
intermediate.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
62(1)
Опубликована: Ноя. 1, 2022
Herein
we
report
the
first
method
for
highly
enantioselective
Brønsted
acid
catalyzed
Heyns
rearrangements.
These
reactions,
by
a
chiral
spiro
phosphoric
acid,
afforded
synthetically
valuable
α-aryl-α-aminoketones
which
cannot
be
obtained
means
of
previously
reported
rearrangement
methods.
This
features
low
catalyst
loadings,
high
yields
and
enantioselectivities,
making
these
reactions
practical.
We
used
to
efficiently
synthesize
various
amines,
including
some
biologically
active
molecules.
experimentally
proved
that
acid-catalyzed
rearrangements
proceeded
via
proton-transfer
process
involving
an
enol
intermediate
stereocontrol
was
realized
during
step.