Hexafluoroisopropanol
(HFIP)-mediated
terminal
selective
heteroarylation
of
allenamides
has
been
accomplished
through
H-bonding
network-enabled
substrate
activation
in
a
robust
fashion.
This
strategy
features
cascade
process
involving
sequential
nucleophilic
addition
followed
by
electrophilic
heteroaromatic
substitution
and
is
well
suited
for
late-stage
functionalization
complex
bioactive
molecules.
The
elucidation
the
underlying
mechanism
was
achieved
comprehensive
combination
several
control
experiments,
kinetic
studies,
isotopic
labeling
isolation
HFIP-allenamide
intermediate
adduct.
ACS Catalysis,
Год журнала:
2024,
Номер
14(14), С. 10882 - 10892
Опубликована: Июль 4, 2024
The
key
structure
of
β-aminosilanes
has
attracted
significant
interest
because
their
latent
biological
activities
in
the
field
medicinal
chemistry.
However,
structural
variety
been
significantly
constrained
by
absence
a
comprehensive
synthetic
approach.
Thus,
development
regiodivergent
catalytic
systems
for
construction
structurally
diverse
via
an
intermolecular
cycloaddition
strategy
would
represent
addition
to
limited
toolkit
available
synthesis.
We
herein
present
attractive
approach
synthesis
through
regioselective
N-allenamides
with
expansion
silacyclobutanes
catalyzed
Pd/PR3.
Just
selecting
suitable
protecting
group
N-allenamides,
regioselectivity
is
completely
switched
efficiently
provide
two
regioisomers
silacyclic
β-aminosilanes.
Two
regioselectivities
were
proceeded
during
migratory
insertion
and
reductive
elimination
process,
origin
which
could
be
well
rationalized
using
density
functional
theory
calculations.
A
palladium-catalyzed
[3
+
2]
cycloaddition
of
cyclopropenones
with
N-allenamides
has
been
developed.
This
methodology
facilitates
the
synthesis
γ-amino-α'-methylenecyclopentenones
in
moderate
to
excellent
yields
good
regioselectivity
and
compatibility
various
functional
groups.
The
employment
as
versatile
2C
synthons
enables
simultaneous
incorporation
both
a
nitrogen
atom
methylene
group
into
cyclopentenones.
Furthermore,
this
approach
exhibits
reverse
when
compared
general
allenes.
Density
theory
calculations
successfully
elucidated
origin
observed
regioselectivity.
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(4), С. 2320 - 2342
Опубликована: Фев. 1, 2024
In
this
study,
we
present
a
novel
and
environmentally
sustainable
protocol
for
the
γ-hydrofunctionalization
of
N-allenyl
compounds
using
various
heteronucleophiles
catalyzed
solely
by
simple
Brønsted
acids.
The
method
displays
remarkable
attributes,
highlighting
its
sustainability,
efficiency,
regio-
stereoselectivity,
as
well
versatile
applicability
to
diverse
heteroatom-containing
enamides.
Notably,
our
approach
eliminates
need
metal
catalysts
toxic
solvents,
representing
significant
advancement
in
greener
chemistry
practices.
We
demonstrate
broad
scope
successfully
scaling
up
reactions
gram-scale
syntheses,
underscoring
robustness
potential
industrial
implementation.
resulting
γ-heterosubstituted
enamides
offer
new
possibilities
further
synthetic
transformations,
yielding
highly
functionalized
with
applications.
Mechanistic
investigations
reveal
pivotal
role
CSA
catalyst,
enabling
alcohol
addition
via
covalent
activation
mode.
Chemical Science,
Год журнала:
2024,
Номер
15(43), С. 17962 - 17970
Опубликована: Янв. 1, 2024
Herein,
we
report
the
first
visible-light-induced
strategy
for
rapid
synthesis
of
densely
functionalized
α-
and
γ-phosphorylated
β-sulfonyl
enamines
in
a
regio-
stereoselective
manner
from
N
-sulfonyl
allenamides
H-phosphine
oxides.
The
site-selective
alkylation
of
α-aminotropones
is
effectively
realized
via
gold(I)-catalyzed
electrophilic
activation
allenamides
and
allenyl
ethers,
yielding
up
to
85%
in
30
examples.
A
dedicated
combined
spectroscopic
computational
investigation
accounts
for
both
chemo-
regioselective
profiles
the
protocol.
New
opportunities
chemical
space
tropone/tropolone
derivatives
are
identified.
Current Organic Synthesis,
Год журнала:
2024,
Номер
21(7), С. 889 - 902
Опубликована: Янв. 4, 2024
Abstract:
Allenamides
are
special
allenes,
and
the
unique
reactivity,
selectivity
(both
stereoselective
regionally
selective)
stability
of
allenamides
have
been
widely
studied.
In
this
review,
development
free
radical
transformation
over
last
few
years
will
be
summarized.
This
review
discusses
in
detail
three
parts:
intermolecular
addition
to
C-
X
(X
=
N,
S,
O,
Se)
bonds,
metal
salt
mediated
cyclization
allenamides,
photocatalytic
allenamides.
addition,
reasonable
details
mechanisms
provided
for
vast
majority
these
transformations.
