Angewandte Chemie,
Journal Year:
2023,
Volume and Issue:
136(1)
Published: Nov. 16, 2023
Abstract
Axially
chiral
open‐chained
olefins
are
an
underexplored
class
of
atropisomers,
whose
enantioselective
synthesis
represents
a
daunting
challenge
due
to
their
relatively
low
racemization
barrier.
We
herein
report
rhodium(I)‐catalyzed
hydroarylative
cyclization
1,6‐diynes
with
three
distinct
classes
arenes,
enabling
highly
broad
range
axially
1,3‐dienes
that
conformationally
labile
(Δ
G
≠
(
rac
)=26.6–28.0
kcal/mol).
The
coupling
reactions
in
each
category
proceeded
excellent
enantioselectivity,
regioselectivity,
and
Z/E
selectivity
under
mild
reaction
conditions.
Computational
studies
the
quinoline
N
‐oxide
system
reveal
proceeds
via
initial
oxidative
1,6‐diyne
give
rhodacyclic
intermediate,
followed
by
σ‐bond
metathesis
between
arene
C−H
bond
Rh−C(vinyl)
bond,
subsequent
C−C
reductive
elimination
being
enantio‐determining
turnover‐limiting.
DFT‐established
mechanism
is
consistent
experimental
studies.
coupled
products
‐oxides
undergo
facile
visible
light‐induced
intramolecular
oxygen‐atom
transfer,
affording
epoxides
complete
axial‐to‐central
chirality
transfer.
Chemistry - An Asian Journal,
Journal Year:
2023,
Volume and Issue:
19(1)
Published: Dec. 5, 2023
Abstract
Iron‐catalyzed
C−H
activation
has
recently
emerged
as
an
increasingly
powerful
synthetic
method
for
the
step‐
and
atom‐
economical
direct
functionalizations
of
otherwise
inert
bonds.
Iron's
low‐cost
toxicity
along
with
its
catalytic
versatility
have
encouraged
scientific
community
to
elect
this
metal
development
new
methodologies.
Within
review,
we
aim
present
a
collection
most
recent
examples
iron‐catalyzed
particular
emphasis
on
modern
strategies
mechanistic
aspects.
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
14(3), P. 2049 - 2057
Published: Jan. 23, 2024
Transition-metal-catalyzed
C(sp3)–H
functionalization
has
been
much
less
investigated
compared
to
C(sp2)–H
because
the
site-selectivity
control
in
bond
activation
is
more
challenging
than
that
activation.
Site-selective
without
assistance
of
directing
groups
highly
desirable,
installation
and
removal
are
not
required.
Hence,
cycloaddition
through
a
site-selective
C–H
triggered
by
formation
metallacycles,
such
as
metalloles,
atom-
step-economical
method
for
synthesizing
complex
carbo-
heterocycles
from
simple
unsaturated
substrates.
Herein,
we
report
cobalt/photoredox
dual-catalysis-enabled
cyclization
1,5,10-enediynes
via
remote
metallole
formation,
affording
axially
chiral
aryl
alkenes.
Several
experiments
theoretical
calculations
suggest
cleavage
proceeds
σ-complex-assisted
metathesis
(σ-CAM)
intermediate.
The Journal of Organic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 10, 2025
A
palladium-catalyzed
new
mode
of
cascade
arylative
cyclization
1,6-diynes
is
disclosed
using
dibenzoxaborin
as
an
arylating
agent
featuring
transmetalation
and
selective
migratory
insertion
the
key
steps.
This
process
enables
efficient
construction
polysubstituted
fused
naphthalene
skeletons
via
formation
three
C-C
bonds
through
dual
regioselectivity
in
both
arylation
well
C-H
functionalization.
Some
control
experiments
kinetic
isotope
effect
(KIE)
studies
were
conducted
to
elucidate
reaction
mechanism,
some
product
diversifications
achieved
showcase
synthetic
potential.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
63(1)
Published: Nov. 16, 2023
Abstract
Axially
chiral
open‐chained
olefins
are
an
underexplored
class
of
atropisomers,
whose
enantioselective
synthesis
represents
a
daunting
challenge
due
to
their
relatively
low
racemization
barrier.
We
herein
report
rhodium(I)‐catalyzed
hydroarylative
cyclization
1,6‐diynes
with
three
distinct
classes
arenes,
enabling
highly
broad
range
axially
1,3‐dienes
that
conformationally
labile
(Δ
G
≠
(
rac
)=26.6–28.0
kcal/mol).
The
coupling
reactions
in
each
category
proceeded
excellent
enantioselectivity,
regioselectivity,
and
Z/E
selectivity
under
mild
reaction
conditions.
Computational
studies
the
quinoline
N
‐oxide
system
reveal
proceeds
via
initial
oxidative
1,6‐diyne
give
rhodacyclic
intermediate,
followed
by
σ‐bond
metathesis
between
arene
C−H
bond
Rh−C(vinyl)
bond,
subsequent
C−C
reductive
elimination
being
enantio‐determining
turnover‐limiting.
DFT‐established
mechanism
is
consistent
experimental
studies.
coupled
products
‐oxides
undergo
facile
visible
light‐induced
intramolecular
oxygen‐atom
transfer,
affording
epoxides
complete
axial‐to‐central
chirality
transfer.
Synlett,
Journal Year:
2024,
Volume and Issue:
35(19), P. 2246 - 2250
Published: Aug. 7, 2024
Abstract
A
Fe(OTf)3
and
γ-cyclodextrin-catalyzed
hydroarylation
of
alkenes
with
1-naphthols
or
2-naphthols
is
demonstrated.
This
efficient
general
method
delivers
a
wide
range
benzylic
naphthols
from
readily
available
starting
materials
high
chemo-
regioselectivity
in
up
to
99%
yield,
no
need
for
strong
base
additive.
