Remote Hydroamination of Disubstituted Alkenes by a Combination of Isomerization and Regioselective N–H Addition
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(7), С. 3875 - 3881
Опубликована: Фев. 13, 2023
Remote
hydrofunctionalizations
of
alkenes
incorporate
functional
groups
distal
to
existing
carbon–carbon
double
bonds.
While
remote
carbonylations
are
well-known,
most
common
for
addition
relatively
nonpolar
B–H,
Si–H,
and
C–H
bonds
with
alkenes.
We
report
a
system
the
hydroamination
disubstituted
functionalize
an
alkyl
chain
selectively
at
subterminal,
unactivated,
methylene
position.
Critical
high
regioselectivity
reaction
rates
electronic
properties
substituent
on
amine
development
ligand
DIP-Ad-SEGPHOS
by
evaluating
steric
effects
modules
reactivity
selectivity.
The
is
compatible
broad
scope
aminopyridines
enables
regioconvergent
synthesis
amines
from
isomeric
mixture
products
can
be
derivatized
nucleophilic
aromatic
substitution
amino
variety
nucleophiles.
Язык: Английский
Strain-Inducing Positional Alkene Isomerization
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(36), С. 20053 - 20061
Опубликована: Авг. 30, 2023
Small,
strained
ring
systems
are
important
pharmacophores
in
medicinal
chemistry
and
versatile
intermediates
organic
synthesis.
However,
the
kinetic
thermodynamic
instability
of
many
molecules
renders
them
challenging
to
prepare.
Here,
we
report
a
strain-inducing
positional
alkene
isomerization
reaction
that
provides
mild
selective
access
cyclobutene
building
blocks
from
readily
obtained
cyclobutylidene
precursors.
This
endergonic
relies
on
sequential
synergistic
action
decatungstate
polyanion
photocatalyst
cobaloxime
co-catalyst
store
potential
energy
form
strain.
The
versatility
products
is
demonstrated
through
diverse
subsequent
strain-releasing
transformations.
Mechanistic
studies
reveal
steric
basis
for
strain-selective
product
formation.
Язык: Английский
Catalytic Contra-Thermodynamic Isomerization–Asymmetric Hydroboration of Alkenyl Alcohols and Amines
ACS Catalysis,
Год журнала:
2024,
Номер
14(7), С. 5458 - 5468
Опубликована: Март 28, 2024
Catalytic
isomerization
of
alkenes
is
a
powerful
tool
for
the
construction
complex
synthetically
valuable
molecules
due
to
their
redox-neutral,
atom-
and
step-economical
nature.
However,
traditional
catalytic
asymmetric
typically
required
use
heteroatomic
group
such
as
OH
or
NR2
thermodynamic
driving
force
(i.e.,
C═C
double
bond
isomerizes
along
direction
groups).
Here,
we
present
contra-thermodynamic
isomerization/asymmetric
hydroboration
alkenyl
alcohols
amines,
in
which
opposite
OR
NR2.
Compared
thermal
isomerizations,
this
reaction
overcomes
unfavorable
bias
form
alkene
intermediate,
followed
by
an
irreversible
terminal
provide
highly
chiral
1,n-boryl
ethers
amines.
This
protocol
shows
wide
substrate
scope,
including
allylic
alcohols,
homoallylic
protected
various
free
The
synthetic
utilities
practicability
method
were
demonstrated
gram-scale
reactions,
diverse
product
transformations,
its
applications
synthesis
bioactive
molecules.
Preliminary
mechanistic
studies
show
that
involves
dissociative
1,1-disubstituted
intermediates.
Язык: Английский
Methoxide‐Enabled Zirconium‐Catalyzed Migratory Alkene Hydrosilylation
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(46)
Опубликована: Июль 24, 2024
A
zirconocene
dichloride-catalyzed
alkene
hydrosilylation
is
reported
that
can
be
applied
to
non-activated
and
conjugated
terminal
internal
alkenes.
It
involves
a
catalytic
Zr-walk
process
leads
selective
conversion
the
linear
product.
Lithium
methoxide
serves
as
mild
catalyst
activating
agent,
which
significantly
increases
applicability
operational
simplicity
in
comparison
earlier
zirconium(II)-based
protocols.
Supported
by
additional
experiments
calculations,
mechanism
via
zirconium(IV)
intermediates
proposed.
Due
benign
nature
ready-availability
of
zirconium
catalyst,
reaction
an
attractive
alternative
established
methods.
Язык: Английский
Methoxide‐Enabled Zirconium‐Catalyzed Migratory Alkene Hydrosilylation
Angewandte Chemie,
Год журнала:
2024,
Номер
136(46)
Опубликована: Июль 24, 2024
Abstract
A
zirconocene
dichloride‐catalyzed
alkene
hydrosilylation
is
reported
that
can
be
applied
to
non‐activated
and
conjugated
terminal
internal
alkenes.
It
involves
a
catalytic
Zr‐walk
process
leads
selective
conversion
the
linear
product.
Lithium
methoxide
serves
as
mild
catalyst
activating
agent,
which
significantly
increases
applicability
operational
simplicity
in
comparison
earlier
zirconium(II)‐based
protocols.
Supported
by
additional
experiments
calculations,
mechanism
via
zirconium(IV)
intermediates
proposed.
Due
benign
nature
ready‐availability
of
zirconium
catalyst,
reaction
an
attractive
alternative
established
methods.
Язык: Английский