Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: Dec. 30, 2024
The
functionalized
polycycle
with
densely
contiguous
tertiary
stereocenters
is
a
formidable
challenge
in
synthesizing
the
parvistemoline
family
of
Stemona
alkaloids.
We
herein
report
their
catalytic,
asymmetric
total
syntheses
13-14
steps
from
commercially
available
2-(methoxycarbonyl)-pyrrole,
featuring
development
and
deployment
an
Ir/Pd-synergistically-catalyzed
allylation
α-non-substituted
keto
esters
secondary
aryl-substituted
alcohols,
stereodivergently
accessible
to
four
stereoisomers.
Using
chiral
Pd-enolate
Ir
π-allyl
complex
under
neutral
conditions,
no
epimerization
occurs.
Additionally,
other
two
adjacent
stereogenic
centers
can
be
installed
diastereoselectively
by
Zn(BH
Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(35)
Published: May 16, 2024
Abstract
The
construction
of
chiral
motifs
containing
nonadjacent
stereocenters
in
an
enantio‐
and
diastereoselective
manner
has
long
been
a
challenging
task
synthetic
chemistry,
especially
with
respect
to
their
stereodivergent
synthesis.
Herein,
we
describe
protocol
that
enables
the
1,5/1,7‐nonadjacent
tetrasubstituted
through
Pd/Cu‐cocatalyzed
Heck
cascade
reaction.
Notably,
C=C
bond
relay
strategy
involving
shift
π‐allyl
palladium
intermediate
was
successfully
applied
asymmetric
1,7‐nonadjacent
stereocenters.
current
method
allows
for
efficient
preparation
molecules
bearing
two
privileged
scaffolds,
oxindoles
non‐natural
α‐amino
acids,
good
functional
group
tolerance.
full
complement
four
stereoisomers
products
could
be
readily
accessed
by
simple
combination
metal
catalysts
different
enantiomers.
European Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
27(46)
Published: Aug. 26, 2024
Abstract
The
chiral
fluorene
fragment
constitutes
one
of
the
most
important
scaffolds
frequently
found
in
numerous
bioactive
molecules,
ligands,
and
advanced
functional
materials
due
to
its
unique
physical
properties.
In
this
context,
various
transition
metal‐
organo‐catalyzed
asymmetric
reactions
have
been
developed
prepare
fluorenes
with
high
optical
purity.
present
mini‐review,
we
summarize
fifteen
years
achievements
catalytic
synthesis
their
derivatives.
Particular
attention
is
given
strategies
used
mechanistic
aspects
some
significant
reactions.
Moreover,
cutting‐edge
developments
silafluorenes
are
also
highlighted.
Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 11, 2024
Abstract
Chiral
2‐azetines
and
allenes
are
highly
valuable
structural
units
in
natural
products
useful
chemicals.
However,
enantioselective
synthesis
of
both
has
been
extremely
challenging.
Herein,
we
present
asymmetric
construction
chiral
(70–98
%
yields
up
to
96
ee)
through
phosphine‐catalyzed
[2+2]
annulation
yne‐enones
with
sulfamate‐derived
cyclic
imines.
These
were
easily
transformed
into
upon
treatment
Et
3
SiH,
BF
⋅
2
O
water
at
rt
for
minutes.
Based
on
the
above
transformations,
a
concise
one‐pot
synthetic
procedure
combining
imines
under
phosphine
catalysis
sequential
reduction/isomerization/ring‐opening
reaction
was
thus
set
up,
providing
axially
tetrasubstituted
satisfactory
enantioselectivities
(56–90
91
ee).
Organic Letters,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 20, 2024
A
Pd-catalyzed
asymmetric
Heck
cascade
reaction
involving
the
intramolecular
carbopalladation
of
unsaturated
hydrocarbons,
followed
by
nucleophilic
trapping
resulting
palladium
species,
is
a
powerful
approach
for
constructing
chiral
N-heterocycles.
However,
use
prochiral
nucleophiles
in
these
reactions
remains
significantly
underexplored.
Herein,
we
report
novel
Pd/Cu
catalytic
system
Heck/Tsuji–Trost
allenamides
and
aldimine
esters.
This
robust
method
allows
rapid
synthesis
wide
range
enantiopure
non-natural
α-substituted
tryptophans
high
yields
(up
to
99%
yield)
with
excellent
enantioselectivities
98%
ee).
Additionally,
synthetic
utility
this
protocol
demonstrated
through
scale-up
experiments
diverse
valuable
transformations.
European Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 27, 2024
Abstract
Chiral
sulfur‐containing
compounds
play
an
important
role
in
asymmetric
catalysis
and
synthesis,
chiral
pharmaceuticals,
materials.
While
great
progress
has
been
made
the
synthesis
of
these
compounds,
catalytic
heterocycles
remains
relatively
limited
compared
to
acyclic
ones.
In
this
study,
we
successfully
report
efficient
highly
selective
structurally
diverse
chirality‐at‐sulfur(IV)
six‐membered
under
mild
conditions
via
a
Pd‐catalyzed
(4+2)
dipolar
cyclization.
More
importantly,
products
enable
enantioselective
preparation
variety
other
S‐stereogenic
derivatives.
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
unknown, P. 18872 - 18883
Published: Dec. 11, 2024
Catalytic
asymmetric
construction
of
atropisomers
with
multiple
stereogenic
elements
has
recently
become
an
emerging
area.
However,
general
methods
that
produced
bearing
remote
1,5-axial
and
central
chirality
efficiently
stereoselectively
are
scarce
yet
highly
challenging.
We
herein
report
a
catalytic
diastereo-
atroposelective
desymmetrizing
alkynylation
axially
prochiral
dialkynes
ortho-quinone
methides
(o-QMs),
furnishing
1,5-remote
centrally
elements.
The
control
axis
far
from
the
reaction
site
could
be
simultaneously
achieved
during
stereoselective
C(sp3)–C(sp)
bond-forming
process
to
generate
center.
In
addition,
kinetic
resolution
racemic
alkynes
via
o-QMs
been
developed,
further
enriching
structural
diversity
1,5-central
axial
chirality.
present
method
expands
chemical
space
atropisomeric
molecules
chiral
by
facile
downstream
diversification
C–C
triple
bonds.
Finally,
can
also
applied
for
motifs
1,9-
1,10-stereogenic
centers.
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: Dec. 30, 2024
The
functionalized
polycycle
with
densely
contiguous
tertiary
stereocenters
is
a
formidable
challenge
in
synthesizing
the
parvistemoline
family
of
Stemona
alkaloids.
We
herein
report
their
catalytic,
asymmetric
total
syntheses
13-14
steps
from
commercially
available
2-(methoxycarbonyl)-pyrrole,
featuring
development
and
deployment
an
Ir/Pd-synergistically-catalyzed
allylation
α-non-substituted
keto
esters
secondary
aryl-substituted
alcohols,
stereodivergently
accessible
to
four
stereoisomers.
Using
chiral
Pd-enolate
Ir
π-allyl
complex
under
neutral
conditions,
no
epimerization
occurs.
Additionally,
other
two
adjacent
stereogenic
centers
can
be
installed
diastereoselectively
by
Zn(BH
