Angewandte Chemie,
Год журнала:
2023,
Номер
136(1)
Опубликована: Ноя. 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.
Organic Letters,
Год журнала:
2024,
Номер
26(31), С. 6586 - 6590
Опубликована: Июль 30, 2024
A
rhodium-catalyzed
[4
+
2]
cycloaddition
of
ynamines
and
2-(cyanomethyl)phenylboronates
has
been
developed,
leading
to
efficient
excellent
regioselective
synthesis
valuable
indole-linked
aromatic
compounds
in
a
concise
flexible
approach.
Interestingly,
this
strategy
was
successful
the
construction
C···N
axially
chiral
indoles
with
high
enantiocontrol
by
introduction
new
phosphoramidite
ligand
(Xie-Phos).
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 17, 2024
Transition-metal
catalyzed
asymmetric
allylic
substitution
with
alkyl
and
heteroaryl
carbon
nucleophiles
has
been
well-established.
However,
the
arylation
of
acyclic
internal
alkenes
aryl
remains
challenging
underdeveloped.
Herein
we
report
a
stereospecific
3-aza-Cope
rearrangement
interrupted
substitution-isomerization
(Int-AASI)
that
enables
arylation.
By
means
this
stepwise
strategy,
both
enantioenriched
products
axially
chiral
could
be
readily
obtained
in
high
enantioselectivities.
Experimental
studies
support
mechanism
involving
cascade
amination,
alkene
isomerization.
Density
functional
theory
detailed
reasons
achieving
chemoselectivity,
regioselectivity,
stereoselectivity
stereospecificity,
respectively.
Angewandte Chemie,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 17, 2024
Abstract
Transition‐metal
catalyzed
asymmetric
allylic
substitution
with
alkyl
and
heteroaryl
carbon
nucleophiles
has
been
well‐established.
However,
the
arylation
of
acyclic
internal
alkenes
aryl
remains
challenging
underdeveloped.
Herein
we
report
a
stereospecific
3‐aza‐Cope
rearrangement
interrupted
substitution‐isomerization
(
Int‐AASI
)
that
enables
arylation.
By
means
this
stepwise
strategy,
both
enantioenriched
products
axially
chiral
could
be
readily
obtained
in
high
enantioselectivities.
Experimental
studies
support
mechanism
involving
cascade
amination,
alkene
isomerization.
Density
functional
theory
detailed
reasons
achieving
chemoselectivity,
regioselectivity,
stereoselectivity
stereospecificity,
respectively.
Angewandte Chemie,
Год журнала:
2023,
Номер
136(1)
Опубликована: Ноя. 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.
