The Chemical Record,
Год журнала:
2023,
Номер
23(5)
Опубликована: Март 9, 2023
Abstract
Aryl
alkenes
represents
one
of
the
most
widely
occurring
structural
motif
in
countless
drugs
and
natural
products,
direct
C−H
functionalization
aryl
provides
atom‐
step
efficient
access
toward
valuable
analogues.
Among
them,
group‐directed
selective
olefinic
α
‐
β
‐C−H
functionalization,
bearing
a
directing
group
on
aromatic
ring,
has
attracted
remarkable
attentions,
including
alkynylation,
alkenylation,
amino‐carbonylation,
cyanation,
domino
cyclization
so
on.
These
transformations
proceed
by
endo
exo
−C−H
cyclometallation
provide
alkene
derivatives
excellent
site‐
stereo‐selectivity.
Enantio‐selective
were
also
covered
to
synthesis
axially
chiral
styrenes.
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.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(20), С. 14719 - 14727
Опубликована: Окт. 4, 2023
An
efficient
palladium-catalyzed
enantioselective
direct
N-alkylation
of
indoles
using
a
novel
type
axially
chiral
styrene-phosphine
ligand
SJTU-PHOS-1
was
developed.
This
reaction
demonstrated
good
functional
group
compatibility
and
wide
range
scope
substrates
in
mild
conditions.
Moreover,
the
DFT
calculations
expounded
coordination
mode
metal
catalyst
enantioselectivity
control.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(46)
Опубликована: Сен. 27, 2022
Although
palladium-catalyzed
asymmetric
C-H
functionalization
and
Heck
reactions
represents
one
of
the
most
important
synthetic
strategies
for
construction
quaternary
stereocenters,
developing
enantioselective
version
PdII
-catalyzed
carbopalladation-initiated
cascade
still
remains
a
formidable
challenge.
Herein,
an
unprecedent
[3+2]
annulation
oxime
ethers
alkynes
has
been
developed,
providing
both
spiro
nonspiro
indenes
bearing
all-carbon
stereocenters
in
good
yields
(up
to
98
%)
with
excellent
enantioselectivities
>99
%
ee).
This
is
accomplished
by
merging
atroposelective
activation/double
carbopalladation
transient
axial-to-central
chirality
transfer
process,
constituting
first
successful
example
catalytic
strategy
involving
axially
chiral
styrene
intermediate.
The Chemical Record,
Год журнала:
2023,
Номер
23(5)
Опубликована: Март 9, 2023
Abstract
Aryl
alkenes
represents
one
of
the
most
widely
occurring
structural
motif
in
countless
drugs
and
natural
products,
direct
C−H
functionalization
aryl
provides
atom‐
step
efficient
access
toward
valuable
analogues.
Among
them,
group‐directed
selective
olefinic
α
‐
β
‐C−H
functionalization,
bearing
a
directing
group
on
aromatic
ring,
has
attracted
remarkable
attentions,
including
alkynylation,
alkenylation,
amino‐carbonylation,
cyanation,
domino
cyclization
so
on.
These
transformations
proceed
by
endo
exo
−C−H
cyclometallation
provide
alkene
derivatives
excellent
site‐
stereo‐selectivity.
Enantio‐selective
were
also
covered
to
synthesis
axially
chiral
styrenes.
