Advanced Synthesis & Catalysis,
Год журнала:
2023,
Номер
365(9), С. 1398 - 1404
Опубликована: Апрель 12, 2023
Abstract
Herein,
we
present
a
chiral
boro‐phosphate
catalyzed
atroposelective
asymmetric
transfer
hydrogenation
method,
leading
to
family
of
axially
styrene‐type
allylalcohols.
This
dynamic
kinetic
resolution
approach
portrays
simple
procedure,
mild
conditions
and
good
enantiocontrol
(51–95%
ee),
thus
providing
an
important
alternative
assemble
the
challenging
atropisomeric
aryl‐acyclic
alkene
scaffolds.
magnified
image
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
63(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.
Synthesis,
Год журнала:
2023,
Номер
56(12), С. 1862 - 1872
Опубликована: Дек. 14, 2023
Abstract
The
construction
of
axially
chiral
alkene
frameworks
is
currently
one
hottest
topics
in
the
field
organic
synthetic
chemistry.
Compared
to
traditional
molecules,
such
as
biaryls,
heterobiaryls,
and
anilides,
synthesis
alkenes
far
more
challenging,
especially
for
acyclic
tetrasubstituted
analogues.
In
this
review,
we
summarized
development
strategies
analogues,
including
asymmetric
difunctionalization,
C–H
functionalization,
cross-coupling,
(dynamic)
kinetic
resolution,
allylic
substitution-isomerization.
1
Introduction
2
Synthesis
Cyclic
Tetrasubstituted
Axially
Chiral
Alkenes
3
Acyclic
4
Summary
Outlook
Here,
an
Ir/Zn-cocatalyzed
atroposelective
[2+2+2]
cycloaddition
of
1,6-diynes
and
ynamines
was
developed,
forging
various
functionalized
C─N
axially
chiral
indoles
pyrroles
in
generally
good
to
excellent
yields
(up
99%),
chemoselectivities,
high
enantioselectivities
98%
enantiomeric
excess)
with
wide
substrate
scope.
This
cocatalyzed
strategy
not
only
provided
alternative
promising
reliable
way
for
asymmetric
alkyne
cyclotrimerization
easy
handle
but
also
settled
the
issues
previous
[Rh(COD)2]BF4-catalyzed
system
on
construction
axial
chirality
such
as
complex
operations,
limited
scope,
low
efficiency.
In
addition,
control
experiments
theoretical
calculations
disclosed
that
Zn(OTf)2
markedly
reduced
barrier
migration
insertion
significantly
increase
reaction
efficiency,
which
distinctly
different
from
work
Lewis
acid
improving
yield
through
accelerating
oxidative
addition
reductive
elimination.
Advanced Synthesis & Catalysis,
Год журнала:
2023,
Номер
365(9), С. 1398 - 1404
Опубликована: Апрель 12, 2023
Abstract
Herein,
we
present
a
chiral
boro‐phosphate
catalyzed
atroposelective
asymmetric
transfer
hydrogenation
method,
leading
to
family
of
axially
styrene‐type
allylalcohols.
This
dynamic
kinetic
resolution
approach
portrays
simple
procedure,
mild
conditions
and
good
enantiocontrol
(51–95%
ee),
thus
providing
an
important
alternative
assemble
the
challenging
atropisomeric
aryl‐acyclic
alkene
scaffolds.
magnified
image
