Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(45)
Published: July 11, 2024
Abstract
Here,
we
report
a
strategy
enabling
triple
switchable
chemo‐,
regio‐,
and
stereodivergence
in
newly
developed
palladium‐catalyzed
cycloadditions
of
allenes.
An
asymmetric
pseudo‐stereodivergent
cycloaddition
allenes
bearing
primary
leaving
group
at
the
α
‐position,
where
dynamic
kinetic
hydroalkoxylation
racemic
unactivated
was
enantio‐determining
step,
is
realized,
providing
four
stereoisomers
[(
Z,R
),
(
Z,S
E,S
E,R
)]
containing
di‐substituted
alkene
scaffold
stereogenic
center.
By
tuning
reaction
conditions,
mechanistically
distinctive
uncovered
selectively
with
same
set
substrates.
switching
position
allenes,
involving
an
intermolecular
O‐attack
disclosed.
Diverse
mechanisms
reactions
enable
rapid
access
to
structurally
stereochemically
diverse
3,4‐dihydro‐2
H
‐1,4‐benzoxazines
high
efficiency
selectivity.
Chemical Reviews,
Journal Year:
2024,
Volume and Issue:
124(14), P. 8657 - 8739
Published: July 2, 2024
Chiral
phosphorus
ligands
play
a
crucial
role
in
asymmetric
catalysis
for
the
efficient
synthesis
of
useful
optically
active
compounds.
They
are
largely
categorized
into
two
classes:
backbone
chirality
and
P-stereogenic
ligands.
Most
reported
belong
to
former
class.
Privileged
ones
such
as
BINAP
DuPhos
frequently
employed
wide
range
catalytic
transformations.
In
contrast,
latter
class
has
remained
small
family
many
years
mainly
because
their
synthetic
difficulty.
The
late
1990s
saw
emergence
novel
with
superior
enantioinduction
ability
Rh-catalyzed
hydrogenation
reactions.
Since
then,
numerous
have
been
synthesized
used
This
Review
summarizes
thus
far,
including
stereochemical
electronic
properties
that
afford
high
excellent
enantioselectivities.
Examples
reactions
use
this
described
together
applications
construction
key
intermediates
natural
products
therapeutic
agents.
literature
covered
dates
back
1968
up
until
December
2023,
centering
on
studies
published
later
years.
The Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
89(3), P. 1846 - 1857
Published: Jan. 12, 2024
Herein,
we
describe
an
efficient
transition-metal-free
regioselective
C3alkylation
of
indoles
for
the
synthesis
bis(indolyl)methanes
and
3-styryl
indoles.
Nitrobenzene
is
employed
as
oxidant
to
oxidize
alcohols
in
presence
a
strong
base
reaction
avoids
use
transition
metals
such
Ru
Mn.
The
protocol
provides
favorable
route
access
biologically
active
compounds
arundine,
vibrindole
A,
turbomycin
B.
Organic Process Research & Development,
Journal Year:
2024,
Volume and Issue:
28(4), P. 949 - 977
Published: April 8, 2024
P-Chiral
phosphorus
ligands
received
little
attention
in
organic
chemistry
until
Knowles
made
his
landmark
contribution
asymmetric
hydrogenation
by
developing
the
P-chiral
CAMP
and
DIPAMP.
The
development
of
accelerated
end
last
century
with
advent
some
highly
efficient
renowned
for
hydrogenation,
including
BisP*,
TangPhos,
QuinoxP*,
DuanPhos,
et
al.
However,
most
reported
were
air-sensitive,
difficult
to
make,
or
lacked
structural
modularity,
hampering
their
availability
applicability.
sterically
electronically
tunable
is
particularly
desirable.
Over
past
decade,
a
family
hindered,
electron-rich,
structurally
tunable,
air-stable
dihydrobenzooxaphosphole
emerged
that
proved
be
versatile
various
transformations.
5
years
witnessed
an
increasing
number
studies
related
these
discovery
unprecedented
catalytic
properties
This
review
highlights
unique
catalysis
applications
synthesis
natural
products
therapeutic
agents.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(7), P. 1483 - 1488
Published: Feb. 12, 2024
Presented
herein
is
a
palladium-catalyzed
asymmetric
(3
+
2)
annulation
reaction
between
1,3-dienes
and
2-formylarylboronic
acids,
proceeding
in
cascade
vinylogous
addition
Suzuki
coupling
process.
Both
electron-neutral
electron-deficient
are
compatible
under
similar
catalytic
conditions,
distinct
regioselectivity
observed
via
functional-group
control
of
1,3-diene
substrates.
A
collection
1-indanols
with
dense
functionalities
constructed
stereoselectively.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(12), P. 2349 - 2353
Published: March 15, 2024
Enantioselective
construction
of
all-carbon
quaternary
centers
has
been
achieved
via
the
palladium-catalyzed
highly
enantioselective
allenylation
oxindoles
with
2,3-allenylic
carbonates
to
afford
a
variety
optically
active
allene
products,
which
contain
oxindole
units
different
functional
groups,
in
high
ee.
The
corresponding
synthetic
applications
have
also
demonstrated.
Chemical Science,
Journal Year:
2023,
Volume and Issue:
14(39), P. 10812 - 10823
Published: Jan. 1, 2023
A
class
of
prochiral
allenylic
di-electrophiles
have
been
introduced
for
the
first
time
as
three-atom
synthons
in
cycloadditions,
and
a
new
type
[4+3]
cycloaddition
involving
transition
metal-catalyzed
enantioselective
sequential
substitution
has
successfully
developed,
enabling
challenging
seven-membered
exocyclic
axially
chiral
allenes
to
be
accessed
good
yields
with
enantioselectivity.
Through
addition
catalytic
amount
ortho-aminoanilines
or
ortho-aminophenols,
racemization
products
is
effectively
suppressed.
Mechanistic
studies
reveal
that
elusive
Pd-catalyzed
intramolecular
rather
than
intermolecular
enantio-determining
step
this
cycloaddition.
By
tuning
ligands,
desymmetric
leading
linear
tri-substituted
tandem
substitution/β-vinylic
hydrogen
elimination
(formal
enynylation)
multi-functionalized
1,3-enynes
achieved
chemodivergently.
The
first
catalytic
enantioselective
Friedel-Crafts
(FC)
allenylic
alkylation
for
the
creation
of
central
chirality
has
been
developed
under
cooperative
Ir(I)/(phosphoramidite,olefin)
and
Lewis
acid
catalysis.
Using
racemic
alcohol
as
electrophile,
this
enantioconvergent
reaction
proceeds
through
an
Ir(I)-stabilized
carbocation
intermediate,
which
is
intercepted
with
a
variety
electron-rich
arenes
heteroarenes.
resulting
highly
enantioenriched
(up
to
>99.5:0.5
er)
1,1-disubstituted
methanes,
bearing
benzylic
carbon
stereocenter,
are
obtained
complete
regiocontrol
–
both
on
(hetero)arenes
well
fragment.
This
protocol
allows
formal
introduction
4
alkane
chains
into
stereocenter.
An
intramolecular
version
FC
also
shown
proceed
promising
enantioselectivity
same
conditions.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Aug. 21, 2024
The
ubiquitous
nature
of
amines
in
drug
compounds,
bioactive
molecules
and
natural
products
has
fueled
intense
interest
their
synthesis.
Herein,
we
introduce
a
nickel-catalyzed
enantioconvergent
allenylic
amination
methanol-activated
allenols.
This
protocol
affords
diverse
array
functionalized
high
yields
with
excellent
enantioselectivities.
synthetic
potential
this
method
is
demonstrated
by
employing
as
nucleophiles
conducting
gram-scale
reactions.
Furthermore,
mechanistic
investigations
DFT
calculations
elucidate
the
role
methanol
an
activator
reaction,
facilitating
oxidative
addition
C-O
bond
allenols
through
hydrogen-bonding
interactions.
remarkable
outcomes
arise
from
rapid
racemization
enabled
nickel
catalyst
highly
enantioselective
dynamic
kinetic
asymmetric
transformation
η
